SmartLIFE SITE MEASUREMENT

SmartLIFE SITE MEASUREMENT Final Report Paul Cartwright, Emmanuel Moulinier and Fran Nowak

BRE is the UK’s leading centre of expertise on the built environment, construction, energy use in buildings, fire prevention and control, and risk management. BRE is a part of the BRE Group, a world leading research, consultancy, training, testing and certification organisation, delivering sustainability and innovation across the built environment and beyond. The BRE Group is wholly owned by the BRE Trust, a registered charity aiming to advance knowledge, innovation and communication in all matters concerning the built environment for the benefit of all. All BRE Group profits are passed to the BRE Trust to promote its charitable objectives. BRE is committed to providing impartial and authoritative information on all aspects of the built environment. We make every effort to ensure the accuracy and quality of information and guidance when it is published. However, we can take no responsibility for the subsequent use of this information, nor for any errors or omissions it may contain. BRE, Garston, Watford WD25 9XX Tel: 01923 664000, Email: [email protected] [email protected], www.bre.co.uk BRE publications are available from www.ihsbrepress.com or IHS BRE Press Willoughby Road Bracknell RG12 8FB, UK Tel@ 01344 328038 Fax: 01344 328005 Email: [email protected] Requests to copy any part of this publication should be made to the publisher: IHS BRE Press Garston, Watford WD25 9XX, UK Tel: 01923 664761 Email: [email protected]

Supplement to BR500, SmartLIFE – Lessons learned Published as pdf file on CD Rom

© Copyright BRE 2008 First published 2008

Executive Summary

BRE undertook a site measurement research programme to study and compare the construction process for the construction of 106 homes in the Fenland District of Cambridgeshire. The study’s specific aim was to compare four different construction methods: • Conventional brick and block construction • Open panel timber frame • Light gauge steel frame • Insulating concrete formwork (ICF).

The 106 homes are located on three sites: • Beaufort Drive, Chatteris, a 15 unit development with all dwellings constructed using open panel timber frame • Norwood Road, March, a 56 unit development of 35 steel framed closed panel dwellings and 21

traditional brick and block dwellings • Hereward Hall, March, a 35 unit development of 15 dwellings constructed using an insulating concrete

formwork (ICF) system and 20 dwellings constructed using traditional brick and block cavity construction.

In total, six house types were used – six types on the Norwood Road site, four on the Hereward Hall site and four at Beaufort Drive. The limited number of house types allowed for a structured comparison between the different construction methods, which is often not possible when a large number of house types are used.

A detailed study of the construction process was undertaken following the digging of the first foundations in September 2006. A site observer/data analyst was based on each site on a full-time basis collecting and analysing the data. The majority of the data was collected using BRE’s performance and resource measurement tools, CaliBRE and SMARTAudit. A total of 140,361 man-hours were monitored on the three sites.

Some of these findings relate directly to issues concerning the application of modern methods of construction while others are generic house construction process issues. In summary the key findings are: • All three sites had site specific issues to tackle. These included access restrictions and scheduling two

construction methods on the same site. • The average man-hours required for the construction on site varied between house types, with some

methods requiring less than others for certain house types. • Over 21,846 man-hours have been non-value-added time as defined by BRE’s work breakdown structure • There are a number of issues relating specifically to the use of modern methods of construction while

other issues are typical of the construction process in general and most had root causes relating to design, methods of work, supply chain management or site management.

• Although there were only three main plan forms, variations in external finishes and internal layouts made it difficult for the assembly teams to achieve the benefits of a learning curve. Often the next plot in sequence needed reference to a new set of drawings and specifications. Even terraces had variations for end of terraces and changes in finish for elevations.

• The only component common to all unit types was the bathroom pod, which was mostly delivered and installed ‘just in time’ with low man-hour requirements and relatively few snags.

• Attempts to use local trades proved counterproductive, especially when the sites were competing for the same trade skills.

• Over 2000 m³ of waste material were recorded during the project, of which some was segregated for recycling. Remedial work due to work methods or design variations and packaging were the main causes of waste.

Contents

Executive Summary iii 1 Background to the project 1 2 Introduction to the sites 4 2.1 Beaufort Drive 4 2.2 Hereward Hall 6 2.3 Norwood Road 8 2.4 House types 10 3 Description of the report outputs 12 3.1 Planned progress against actual progress 12 3.2 Resource utilisation: operatives on site 13 3.3 Output rates: man-hours per dwelling 13 3.4 Performance 14 3.5 Waste measurement 14 3.6 Opportunities for Improvement 14 3.6.1 Causes of process waste 14 3.6.2 Issues relating to design 16 3.6.3 Issues relating to managing the supply chain 17 3.6.4 Issues relating to managing the site 17 3.6.5 Issues relating to methods of work 17 4 Summary data 18 5 Beaufort Drive 19 5.1 Overall resource footprint 19 5.2 Progress on site 21 5.3 Substructure 21 5.3.1 Speed of build 22 5.3.2 Performance summary 24 5.3.3 Internal/local drainage 25 5.4 Superstructure 27 5.4.1 Overall resource footprint 27 5.4.2 Timber frame erection 28 5.4.3 Roof construction 31 5.4.4 External skin 32 5.5 Bathroom pods 33 5.6 Internal works and finishes 34 5.7 Waste measurement 35

6 Hereward Hall 39 6.1 Overall resource footprint 39 6.2 Progress on site 41 6.3 Substructure 43 6.4 Superstructure 45 6.4.1 ICF houses 45 6.4.2 Design Issues 48 6.4.3 Brick and block cavity wall construction 49 6.5 Bathroom pods 51 6.6 Internal works 52 6.7 Waste measurement 52 7 Norwood Road 55 7.1 Overall resource footprint 55 7.2 Progress on site 56 7.3 Substructure 58 7.4 Superstructure 59 7.4.1 Light gauge steel frame erection 59 7.4.2 Conventional brick and block construction 61 7.4.3 Bathroom pods 64 7.5 Internals 65 7.6 Final finishes 67 7.7 Waste measurement 69 8 Conclusions 72 8.1 Data limitations 72 8.2 Beaufort Drive 72 8.3 Hereward Hall 73 8.4 Norwood Road 73 8.5 Lessons Learnt 74 Appendix A: CaliBRE Performance Measurement Toolkit 82

Appendix B: SMARTAudit Waste Measurement 84

Appendix C: SmartLIFE and the measurement process overview 86

Appendix D: Schedule of construction methods and house types for the project 88

SmartLIFE Site Measurement – Final Report

1

1 Background to the project

The construction phase of the SmartLIFE project comprised the construction of 106 new homes in the Cambridgeshire towns of March and Chatteris, which have become home to both private buyers and housing association tenants. The process of constructing them was a demonstration and training scheme involving some of the leading organisations responsible for shaping affordable housing policy and creating sustainable communities.

English Partnerships, the Housing Corporation, Fenland District Council and the Department for Communities and Local Government are funding the project. It was led by SmartLIFE, a joint venture between Cambridgeshire County Council and BRE. Fenland District Council and Home Group, one of the largest housing providers in the UK, were key partners in driving forward the development.

The project was developed to examine how modern methods of construction (MMC) could be used to alleviate housing shortages in growth areas. Its unique aspect is the extent to which every step of the construction process has gone under the microscope to assess issues such as build speed, build quality, the sustainability of the construction process and the post-occupancy performance of the resulting houses, including energy efficiency.

Avebury, a practical construction consultancy and architects, together with architects Churchill Hui and Proctor and Matthews worked with three leading manufacturers of innovative buildings systems, Fusion, Pinewood Structures and Polarwall Insulating Concrete Formwork. Inspace Partnerships – Regeneration and New Homes Ltd were the main contractor and calfordseaden LLP provided an extensive range of services as the employer’s agent including EcoHomes assessment, Housing Quality Indicator assessment, life cycle costing and general cost advice, as well as providing advice from their extensive experience of modern methods of construction.

The project examined a raft of issues connected with using modern methods of construction and conventional brick and block construction in order to compare and analyse different systems and to identify potential improvements.

Three innovative construction systems were used: • Fusion StIF™ panelised steel frame system for Norwood Road • Pinewood Structures panelised timber frame system for Beaufort Drive • Polarwall Insulating Concrete Formwork (ICF) system for Hereward Hall.

The systems were used to build approximately 60% of the homes: the other 40% were built using conventional brick and block constructions. A mix of terraced, detached and semi-detached properties were constructed with two, three and four bedrooms. See Appendix D.

The number and variety of houses involved means that a wide selection of real-time measurements were taken and assembled in various permutations to assess what worked well and the opportunities for improvement.

SmartLIFE Site Measurement – Final Report 2

Measurements were taken using BRE’s CaliBRE and SMARTAudit systems. The same set of measures were obtained for each building system and the ‘brick and block’ houses. See Appendix C.

CaliBRE was used to map the construction process, identify and code packages and tasks, monitor site construction processes and produce analysis, reports and feedback for the construction team. In addition, the data collected was used to assess the project against benchmarks using the Constructing Excellence Key Performance Indicators (KPIs).

Sustainability KPIs will be used, including waste produced. SMARTWaste, BRE’s web-based ‘Site Methodology to Audit, Reduce and Target Waste’ was used to evaluate the waste produced, enabling the contractor to identify how it was generated and the potential for reducing it.

The effect of the 106 new homes on the environment and locality were assessed both during and post-construction. Measures will be taken of the proportion of ecologically valuable habitat created or retained within the area. Finally, the whole life performance of the finished buildings will be assessed to examine issues such as energy efficiency based on the manufacture, installation, maintenance, repair and replacement of key components.

The development is split across three sites – Beaufort Drive, Hereward Hall and Norwood Road. Each site and each system was the responsibility of a dedicated architect. At Beaufort Drive, there are 15 Pinewood Structures timber frame homes, at Hereward Hall there are 15 Polarwall insulating concrete formwork homes and 20 conventional brick and block homes and at Norwood Road, there are 35 Fusion light gauge steel frame homes and 21 conventional brick and block homes. See the table in Figure 1.

Each design had to show how it reflected local and national guidance in terms of design and the creation of sustainable communities. In addition, the designs complied with Housing Corporation Scheme Development Standards (SDS). In terms of site layout, comfort and security were important. The layouts were designed to promote creative children’s play and encourage residents to use their streets in ways that reduce social isolation, particularly amongst older people. Each site has achieved Secured by Design accreditation, which focused on issues connected with crime prevention.

In addition, each home was designed to optimise sunlight and daylight used to minimise energy consumption. Gardens have been positioned for maximum benefit – south-facing, wherever possible – with minimal ‘over-shading’ from trees and other buildings. Energy-efficiency best practice has been adopted with wall construction U-values of at least 0.27 w/m2K. The development achieved an EcoHomes rating of ‘very good’. EcoHomes is the homes version of BREEAM, the BRE Environmental Assessment Method, which balances environmental performance with the need for a quality standard of living. The issues assessed are grouped into seven categories: • Energy • Water • Pollution • Materials • Transport • Ecology • Land use • Health and well-being

The development will help to meet the current demand for housing in the Fenland area, with 48% of the 106 properties designated for rent or shared-ownership, the rest are for private sale.


3

Occupancy2 bed 4 person

3 bed 5 person

4 bed 6 person

Site

Construction method A Type E Type B Type B Type 4 bedroom

Total

Beaufort Drive

Timber frame 5 5 5 15

Conventional brick and block 8 7 5 20 Hereward Hall Insulation concrete formwork 5 5 5 15

Light gauge steel frame 18 12 5 35 Norwood Road Conventional brick and block 2 10 9 21

Total 106

Figure 1: Summary of the number of plots by construction method and house type


2 Introduction to the sites

2.1 Beaufort Drive

The Beaufort Drive site in Chatteris, the smallest site, involved the construction of 15 timber framed houses using the Pinewood Structures Ltd timber frame system. The construction used open panel timber frames combined with floor cassettes and light gauge steel framed bathroom pods. The construction began in September 2006 and was completed in October 2007.Three different house types were used and a mix of sale, shared ownership and rented houses were constructed.

Figure 2: Timber frame erection Figure 3: Plot 12 completed


5

Figure 4: Artist’s impression of the Beaufort Drive development

Figures 5: Schematic site plan of Beaufort Drive

1

2

8

10 9

11

13

12

5

3 4

Jan Timber Frame

6

1415

7

B

E

A

Type


2.2 Hereward Hall

The second SmartLIFE site involved the construction of 15 insulating concrete formwork (ICF) units and 20 units of traditional brick and blockwork cavity construction units. The ICF units were constructed using the Polarwall external wall system in which blocks of polystyrene are fitted together to form a cavity that is filled with concrete to form the structure of the house. The construction began in September 2006 and was completed in February 2008. Three houses types were used as detailed in the schematic site plan in Figure 9.

Figure 6: Erecting the insulating formwork Figure 7: Plots 4 to 6

Figure 8: Artist’s impression of the Hereward Hall development


7

Figure 9: Schematic site plan of the Hereward Hall site

1 2 3

13

7

910

128

11

14

15

17

18

19

21

23

20

2224

35

32

25 26

27 28

16

29

31

30

34

33

4 65

Brick and Block Polarwall ICF

Type

B

E

A


2.3 Norwood Road

The final site is Norwood Road, a development of 35 panellised steel frame houses and 21 traditional brick and block cavity construction houses. The 35 steel frame houses were constructed using the Fusion StIF™ panelised steel frame system. Construction began in September 2006 and was completed in September 2007. Four house types were used as detailed by the schematic site plan in Figure 13.

Figure 10: Row of light gauge steel framed terraced Figure 11: Conventional brick and block houses houses

Figure 12: Artist’s impression of the Norwood Road development


9

Figure 13: Schematic site plan of Norwood Road

1 2 3

4

6513 7 9 10

128

1114 15 16

17 18

19

21

23

20

22

24 25

26 27 28 29

35 36

34 33 32 31 30

39

53

38

37

40

41

42

43

4445

47

48

46

49

50

52

54 55 56Steel Frame

Brick and Block

B

E

A

B4

Type


2.4 House types

Three main house types were used on all three sites, A, B and E. Norwood Road also had a four bedroom house type (B4) built using conventional brick and block construction. All three house types were built using both conventional brick and block construction and modern methods of construction.

Figure 14: House type A, 2 bed/4 person house to the right of the picture

Figure 15: House type B, 3 bed/5 person


11

Figure 16: House type E, 3 bed/5 person. L- shaped house with roof terrace house

Figure 17: House type B4, 4 bed/6 person. L shaped ground floor detached house without roof terrace


3 Description of the report outputs

The measurement of the construction process using the CaliBRE and SMARTAudit measurement tools allows a number of outputs to be produced. These outputs are explained in detail below. See Appendices A and B for more information about these tools.

3.1 Planned progress against actual progress The data collected by the observers was used to produce a chart that lists all the work carried out on each of the dwellings per day or per week. By using a shaded colour area to represent the original planned programme and numbers to represent the actual progress of a particular stage of the construction, one can immediately see how closely the work followed the planned schedule. This provides a useful performance indicator based on predictability i.e. percentage achieved progress against planned programme.

The list of dwellings is arranged in the order they were constructed and set out vertically, with the first dwelling at the bottom. Each succeeding week is added alongside the previous one, so a picture of the actual progress of the site emerges.

Some stages of work follow the original planned sequence but more often a break from the sequence occurs.

When the planned programme is followed exactly we see all of the numbers (representing the work observed), fall within the shaded area.

A major breakdown in the sequence can cause inefficiencies in the process and make control of the site difficult particularly because it disguises the measure of progress. In this example the original programme has not been followed and some fragmentation (repeat visits) has occurred.

Figure 18: Planned progress versus actual progress

Ju ly August22 23 17 18 19 20 21 24 25 26 27 28 31 1 2 3 4 7 8 9 10 11 14 15 16 17 18

9 # # # # ## # # # # #

# # # # # #

# # # # #

# # # # #

# # # # #

# # # # #

# # # # #

# # # # #

# # # # #

# # # # #

# # # # #

# # # # #

# # # # #

# # # # #

# # # # #14 1415 15

12 1213 13

10 1011 11

8 89 9

6 67 7

4 45 5

2 23 3

D ates

1 1

July August22 23 17 18 19 20 21 24 25 26 27 28 31 1 2 3 4 7 8 9 10 11 14 15 16 17 18

9 # # # # ## # #

# # # #

# # # # #

# # # # #

# # # # #

# # # # #

# # # # #

# # # # #

# # # # #

# # # # #

# # # # #

# # # # #

# # # # #

# # # # #

# # # # #14 1415 15

12 1213 13

10 1011 11

8 89 9

6 67 7

4 45 5

2 23 3

Dates

1 1


13

3.2 Resource utilisation: operatives on site

From the collected data, a complete record of site attendance is available. In fact only the number of operatives in each gang or trade is needed to compare rates of progress and to predict gangs required to cope with future progress rates.

Figure 19: Number of operatives on site per day (traditional superstructure) The height of each bar represents the number of operatives on the site during that day or week. In the case shown in Figure 19 (traditional superstructure) there is a large gang with a build up of labour at the beginning and a tail off at the end. Care should be taken to note whether the resources are plotted per week or day.

3.3 Output rates: man-hours per dwelling

The CaliBRE process is based on a sampling technique. If the number of observations allocated to a dwelling type is small, the accuracy of that figure as a measure of the number of man-hours is low. Greater accuracy can be obtained by taking the average for a group of dwellings of similar design or construction, as applied to SmartLIFE.

The dwellings are arranged in order of construction and each dwelling is represented by a bar of length to correspond with the number of man-hours spent on that dwelling. The example shown in Figure 20 indicates a steady rate of production.

Figure 20: Average number of man-hours per dwelling

100 10050 50

150 150200 200250 250300 300350 350400 400450 450

550 550500 500

600 600650 650700 700750 750800 800

900 900850 850

1000 1000950 950

Man-hour

1050 1050

19 8 18 136 21 9 7Man-hour 11 5 10

205

234

208

316

261244

273

251

198

293

226

263

191

234219

204 207

0

50

100

150

200

250

300

350


3.4 Performance

Each observation made by the observers includes a code for the activities being carried out by the operatives. By analysis one can find what percentage of their time was spent doing each of these activities and as a result one can have a measure of the productivity rates. These productivity rates are recorded on a histogram and plotted per dwelling. The four colours represent the four main activity groupings as shown on the right.

The example shown on the right is an ‘ideal’ with very little non-productive time being achieved without substantial productive support time (supervision).

Here one can see that several of the dwellings have a higher than usual non-productive percentage. This usually indicates where difficulties have occurred, either with the design, the supply chain, the site management or the methods of work.

Figure 21: Performance plot shown as a percentage of man-hours

3.5 Waste measurement

In addition to measuring the site performance in terms of the labour resource efficiency the observer also collects information, through the application of SMARTAudit, on what waste is produced on site. The observer records the different waste products put in the waste material skips, their volumes, from which work package they were produced and from which plots and areas of the site the waste is produced.

3.6 Opportunities for Improvement

The data analysed enables the user to identify where non-value-added time has been spent. Then, following feedback from the site team, causes of the non value added time can be investigated. A detailed explanation of the causes of ‘non waste’ are provided in the following section.

3.6.1 Causes of process waste Construction can be a wasteful process, not only in terms of wasted materials, but also wasted man-hours. Activity sampling, and the subsequent analysis of the monitored data, can identify and quantify that wasted effort.

10 10

0 0

50 50

80 80

100 100

%8 18 13% 11 5 10 6 21 9 7 19

-20%

0%

20%

40%

60%

80%

100%

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17

100

80

60

40

20

0

20

128 129 130 131% 122 123 124 125 126 127

-20%

0%

20%

40%

60%

80%

100%

122 123 124 125 126 127 128 129 130 131


15

In terms of human resources it is relatively easy to identify certain types of ‘non-added-value’ activities, shown in Figure 22 as the red columns, such as repeat work, double handling and not working at the workplace.

0

40

80

120

160

200

BK C F H1 H2 N P RO RT SU T1 T2 U W

Figure 22: Typical activity breakdown in man-hours

Here the 100 man-hours for rework are typical of the snagging or hand-over stage. Strategies for reduced or zero defects would aim to minimise rework. There are, though, other types of activity which are equally wasteful such as taking too long to complete a task and a lack of continuity in the overall process leading to repeat visits or delays in starting subsequent packages. The causes of this waste are analysed in later chapters for each project.

In order to extract this information, data is first collected on what activities individuals are engaged in (see the Activity Code Chart in Figure 23). The non-productive time can then be analysed and the cause of the waste identified with reference to the figure.

Added Value Statutory

Non-Added-Value

SupportSU Supervisio n

T1 Setting out

T2 Testing and checking

No t seen d uring ob servation round

Handling mater ials fro m stores to workplace

Not working and not at the workplace

Not working at the workplace

Making g ood or correcting

Walking around site

A

H1

I

N

RT

W

Carrying out the p rescribed task

Preparation of materials

F

P

Handling mater ials at the workplace

Unlo ad ing

H2

U

C Cleanin g

HS Carrying out work related to health and safety

related to sa fety

RO Inclement weather

BK Taking break

Figure 23: Activity codes for the activity sampling


From this chart, packages running head of programme can be observed as well as those which have started late and/or overrun. In order to use this information a measure of predictability was devised as a (KPI) key performance-indicating tool.

Here the opportunity for managers to improve their predictability includes making a better plan using the knowledge gained from the monitored data.

The CaliBRE methodology includes a feedback system to identify and categorise the causes of waste, the site team’s strategies for dealing with it and the identification of broader lessons related to these causes.

BRE has analysed numerous sites using the CALIBRE system over the past 20 years, and the findings from these sites have shown that CaliBRE issues usually fall into four main areas: • Design • Site management • Managing the supply chain • Methods of work, and also • Miscellaneous reasons

In practice the feedback system breaks the causes down into much greater detail, but for the purposes of this appraisal each project is looked at under these categories.

The four main categories (plus miscellaneous) of the causes of identified process waste used in the feedback system are illustrated in Figure 24, which is an example from a conventional brick and block site.

Figure 24: Typical percentage breakdown of causes of waste Generally the approach is to quantify where empirically possible, the resource wasted, identify the cause, obtain details of any plan of action to deal with the waste and monitor the implementation. This feedback is generally carried out on a regular basis with the site management team. So, for example, if double handling was identified as a significant waste then the cause might be a supply chain issue or a site management issue.

3.6.2 Issues relating to design In general the non value added time ensues from a failure on the part of the design team to appreciate the effect of their decisions on the construction process. This assessment of buildability is one of the CALIBRE outputs that differs with the more usual analysis of efficiency and performance in other time and motion studies. This unique offering enables it to provide a more formal channel of communication from the work

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Cause

Supplier managementshortcomings

Project managementshortcomings

Miscellaneous reasons

Methods of work

Design Specification


17

face back to the design team. A better understanding of these construction processes can lead to an opportunity for improvement in buildability at the design stage and throughout the construction process.

3.6.3 Issues relating to managing the supply chain Much time wastage ensues from a failure on the part of the specialist design consultants (e.g. mechanical and engineering consultant) to plan in sufficient detail. For example, services suppliers often lacked detailed layout drawings when they need them. In those cases where development was still taking place on site, following suppliers suffered a knock-on effect of delayed starts and an increased number of visits needed to carry out their work.

3.6.4 Issues relating to managing the site In this case the waste in resources ensues from a failure on the part of the project management team to predict and control the construction process on site. For most of the projects monitored, the management had little historic information to help plan the projects, so predictability was generally low. This showed up particularly in delays at the foundation stages of many of the studies. Improving the feedback and understanding of these construction processes provide an opportunity for improvement in performance by the project team. Other aspects of site management monitored included material waste reduction, safety issues and tidiness.

3.6.5 Issues relating to methods of work Although much of the resource waste arises from a failure on the part of the design team to appreciate the effect of their decisions at the work face, traditional work practices are also a substantial contribution. In the assessments of performance note is taken of the interaction between the trades and the knock-on effect of any snagging or unfinished work. A better understanding of these construction processes at the work place, feeds back to the whole project team to design and plan opportunities for improvement.


4 Summary data

The table in Figure 25 summarises some of the key statistics from the three sites.

Indicator Beaufort Drive Hereward Hall Norwood Road

Total man-hours monitored for the site 23,318 48,930 68,113

Average number of man-hours on site per day 104 192 313

Average number of operatives on site per day 14 27 43

Total non value added hours for the site 4,967 11,348 7,531

Percentage of non value added hours 12.7 23.2 11

Volume of waste produced (excluding inert waste from site clearance and foundation excavation) (m³)

236 710 879

Figure 25: Summary of data collected on the three sites


19

5 Beaufort Drive

Beaufort Drive, the smallest of the three SmartLIFE sites, was also the most restricted site in terms of access. The site shared an access road with a small existing development. This was shown to be a major constraint for the project. Access to the existing development had to be maintained for long periods and so infrastructure works including drainage could not be carried out efficiently.

5.1 Overall resource footprint

The table in Figure 27 provides an overview of the average man-hours per plot for the site showing the breakdown for certain components. The average number of man-hours per plot for the timber frame erection was 51 man-hours. The average man-hours per plot for the superstructure including the outer skin of brickwork and blockwork, rendering and weather boarding was 378 man-hours. The overall labour resource input is over 1,000 man-hours per plot. This increases to 1,554 including site management and infrastructure which is high for this site due to the low number of plots.

Average man-hours per plot for timber frame erection 51

Average man-hours for timber frame superstructure including scaffolding, brickwork skin and external finishes

378

Average man-hours per plot for all works excluding site management and infrastructure works 1,002

Average man-hours per plot including site management and infrastructure works 1,554

Figure 26: Average resource input for timber frames houses (man-hours)

Most of the labour input was in the period from February 2007 to June 2007 as illustrated by Figure 27. The timber frame commenced in January 2007 and following this, the number of operatives on site increased as trades were required for internal works and external finishes. The footprint shows a gap in the ground worker resource in January. This is due to the ‘tight’ site layout which meant that it was impractical for the ground workers to stay on site at the same time as the first blocks of timber frame were being erected. Access to their work areas was restricted by the crane and other timber-frame-related work on site.


0

40

80

120

160

200

240

280

320

02/10

/06

17/10

/06

01/11

/06

15/11

/06

30/11

/06

15/12

/06

11/01

/07

26/01

/07

12/02

/07

27/02

/07

14/03

/07

29/03

/07

17/04

/07

02/05

/07

18/05

/07

05/06

/07

20/06

/07

05/07

/07

20/07

/07

06/08

/07

30/08

/07

RendererFloor cov ererPlastererPainterInsulation InstallerWall/Floor TilerRoof tilerCarpenterElectriciansSite LabourerTimber FrameForkLif t Driv erScreederScaf f olderPlumbersBeam & block installerFence InstallerBrickLay erGround worker

Num

ber

of M

an-H

ours

Figure 27: A resource footprint over the course of the project showing average daily resource usage for each trade on Beaufort Drive

Figure 28: Comparison of average resource usage for the different house types for each work package

0

200

400

600

800

1,000

1,200

1,400

B A E

MA

N-H

OU

RS

Final finishes

Internals

Superstructure

Substructure

HOUSE TYPE


21

5.2 Progress on site

Figure 29: Progress chart showing the main stages of the construction process for the Beaufort Drive site

• There are four distinct construction phases. The first phase includes plots 4 to 12, the second phase includes plots 1 and 2, the third phase includes plot 13 and the fourth phase includes plots 14 and 15

• The timber frame erection period ranged from two to nine weeks depending on the phase. • Internal works took over 25 weeks per plot, in accordance with the planned programme, for most plots.

Multiple visits were required by the internal trades to complete the plots.

5.3 Substructure

The substructure stage of construction at Beaufort Drive involved the use of the three different construction methods. These methods were selected according to the ground conditions of this brownfield site. Trench fill foundations were used for the majority of the plots including plots 3 to 12, 14 and 15. Raft foundations were used for plots 1 and 2 and a strip footing with blockwork was used for plot 13. Storage space was very limited and therefore the foundations for plots 14 and 15 were not constructed until the road and storm drains under the road were finished to maintain continued access for the residents to the existing properties.

Sept 0

Feb Mar Apr May June July AugDecember October November 25 2 10 16 23 30 6 13 20 27 4 11 18 3 8 15 22 29 5 12 19 26 5 12 19 26 2 9 1

623 30 7 14 21 28 4 11 18 25 2 9 16 23 30 6 13 20 28

Week Number

4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51

plot 004plot 005plot 003plot 006plot 007plot 008plot 009plot 010plot 011plot 012plot 001plot 002plot 013plot 014plot 015

Week Number

Substructures Timber frame erection

Internal works and external skin


FOUNDATIONS AVERAGES by TYPE

0

20

40

60

80

100

120

140

160

180

B3 (1) A2 (2) E3 (1) A2 (RAFT)

HOUSE TYPES

Raft foundationsTrenchfill foundationsInsulationFloor screedDrainage: InternalBlockwork to DPCBeams and Block

STRIP FOUNDATION

0

50

100

150

200

250

300

350

400

450

500

13Plot No

Strip footingsw ith blockw orkInsulation

Floor screed

Drainage:InternalBlockw ork toDPCBeams andBlock

Figure 30: Comparison of man-hours for the different substructure methods by house type

The substructure construction for plot 13 was the most labour intensive, accounting for 485 man-hours. This was substantially higher than the average of 113 man-hours recorded for the other plots. A different foundation design was used, strip footings and blockwork which are more complex than the trench fill design used for most of the plots, to take into account the risk concerning the stability of the adjacent party wall and obstructions in the ground.

5.3.1 Speed of build

Trench fill foundations

The main method used was trench fill foundations. This was by far the fastest and most resource efficient method of construction taking on average 16 man-hours per plot in contrast to 125 man-hours per plot for the raft foundations and 312 man-hours for the strip footings and blockwork for plot 13.


23

Figure 31: Excavating trench for plot 8 Figure 32: Pouring concrete for plots 10 and 11

Strip footings with blockwork

Strip footings with blockwork were used for the foundation on plot 13. The ground conditions in this area of the site meant a different foundation system was required and one that was more complex than the trench fill design used for most of the plots. The foundation took into account the risk concerning the stability of the adjacent party wall and obstructions in the ground. The management team and the ground workers worked out a solution on site that suited the ground conditions but it was more expensive in cost, build duration and resource utilisation than using trench fill solution.

The construction began in January, three months after most of the other foundations. The foundation required 312 man-hours to complete. The main reason for the greater resource usage than a trench fill foundation was the requirements for timber shuttering as wells the time spent excavating soil and laying blocks.

Figure 33: Fix timber shuttering Figure 34: Fix timber shuttering


Figure 35: Blockwork built on concrete footing Raft foundations

Raft foundations were used for plots 1 and 2. The ground conditions included existing foundations from an old development which meant this method was suitable for this area of the site. The initial excavation took place in October 2006 but most of the work including the reinforcement and concrete pour were carried out in February 2007. The average resource requirement for the complete substructure construction of these two plots was 158 man-hours per plot. This is significantly higher than for the trench fill foundations but lower than the resource required for strip footings and blockwork required for plot 13.

Figure 36: Fixing reinforcement Figure 37: Foundation following concrete pour

5.3.2 Performance summary There was a direct correlation between the higher resource usage and the amount of non value added time meaning plot 13 with the highest resource usage also had the highest proportion of non value added time. The performance chart below shows that the number of man-hours of non value added time was close to 100 for plot 13 and over 30 man-hours for both plots 1 and 2.

The high proportion of non value added was due to project management issues with the ground works contractor and delays in finalising the foundation method to be used for the three plots.


25

Figure 38: Performance for foundations in man-hours

Impact on the program

In addition to a higher proportion of non value added time required for some of the foundations, there was also an impact on the programme.

Plot Number Build Duration 1 7 weeks 2 8 weeks 3 1 day 4 5 days 5 5 days 6 5 days 7 5 days 8 2 days 9 2 days 10 2 days 11 2 days 12 2 days 13 17 weeks 14 3 days 15 3 days Figure 39: Comparison of build duration for foundations

5.3.3 Internal/local drainage Further issues affecting the substructure stage of construction related to the internal drainage. Although, some of these issues were not remedied until other stages of the construction were underway they are accounted for within the substructure stage.


Design and management issues

On a number of plots internal drainage was added or moved due to drawing errors showing the wrong positions for drainage. Specific issues included drains located under the timber frame sole plates and omission of drains for the downstairs bathroom.

Figure 40: Digging hole to add drainage for shower Figure 41: Drainage position conflicting with sole plate position

The non value added time relating to the internal drainage was highest for plots 3, 4, 8, 9, 10 and 11. In total, 42 percent of the internal drainage work has been defined as non value added time equating to a total of 156 man-hours.

Figure 42: Performance per location (man-hours) The impact of these drainage issues was a delay to the timber frame erection and an increase in man-hours for the timber frame erection for remedial work to the sole plate fixing.


27

5.4 Superstructure

5.4.1 Overall resource footprint

Figure 43: Summary of man-hours per plot for timber frame superstructure construction Figures 43 and 44 illustrate the resource used for the superstructure construction for each plot and the average for each house type respectively. Plots 8 to 11, house type E3, are clearly the least resource intensive while 3,4,5 and 13, house type B3, are the most resource intensive.

The key reasons for the greater resource utilisation for the B type houses are: • The design with a roof terrace required a larger resource requirement for the external finishes with an

average of 107 man-hours per plot.

0

100

200

300

400

500

600

700

800

900

3 (B) 4 (B 5 (B) 6 (A) 7 (A) 8 (E) 9 (E) 10 (E) 11 (E) 12 (E) 1 (A) 2 (A) 13 (B) 14 (E) 15 (A)Plots in sequence

Man

-Hou

rs p

er P

lot

Windows/ Doors

Total externalfinishesTotal roof

Brickwork

Pods, 1st fix etc

Timber frame

Scaffolding


• The already high requirement for brickwork was increased due to remedial work to plot 5. • Plots 3 to 5 were among the first plots on which the timber frame was erected and therefore were at the

beginning of the ‘learning curve’ on the site.

Figure 44: Average man-hours per house type for superstructure construction (for each work package)

5.4.2 Timber frame erection The timber frame erection began in January 2007 with the construction of plots 3 to 7 followed shortly afterwards by plots 8 to 12. Two gangs of timber frame erectors were used with one gang completing plots 3 to 7 and the other working on plots 8 to 12.

0

100

200

300

400

500

600

700

B A E

Man

-Hou

rs p

er P

lot

Windows/ DoorsTotal external finishesTotal roofBrickworkTotal pods, 1st fix etcTimber frameScaffolding

House types


29

Figure 45: Man-hours per plot for timber frame erection

An average of 51 man-hours per plot was spent on the timber frame erection. This is typical for the erection of a timber frame house of this size. Plots 1 and 2 had the highest resource requirement with an average of 73 man-hours required for the timber frame erection for each plot. These two plots were constructed together later in the process. The higher resource requirement reflects the use of the crane for only two plots while the other plots were constructed in larger blocks sharing the use of the crane and lowering the average resource usage.

Figure 46: Timber frame erection Figure 47: Double handling roof trusses

0

10

20

30

40

50

60

70

80

90

3 4 5 6 7 8 9 10 11 12 1 2 13 14 15Plots in sequence

Man-hours

Timber frame


Performance

The timber frame erection did encounter some issues during the process that affected the efficiency of the construction process. Some of these have been discussed earlier in the report. Other issues are discussed in the subsequent sections.

-40

-20

0

20

40

60

80

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

StatutoryNon Added ValueAdded Value SupportAdded Value

Man

Hou

rs

Figure 48: Performance per plot for timber frame erection (man-hours)

Figure 48 clearly shows the greatest number of non value added man-hours relates to plots 8 to 11. In total 140 man-hours of non value added time relates to the timber frame erection that equates to 20% of the resource used. 60 man-hours of this time were spent on return visits for remedial work and 10 man-hours were spent double handling materials.

In addition to the efficiency of the construction process there were also differences in build duration. Plots 1, 2 and 13 were erected in one week while other plots took three to four weeks. The different in build duration can be attributed to the different in approach. A horizontal approach was taken for the erection of plots 3 to 12 whereby the construction of all 9 plots began in the same two week period. In contrast, plots 1,2,13, and 14 were erected in smaller blocks following a vertical approach to get the roof on quickly.

The impact of the horizontal approach was a congested site while the timber frame erection took place. This prevented the ground workers from completing their work and also delayed the start of the internal trades until the first plot had the roof on. This impact on the critical path meant that the project ran over the planned finish date. There was also unnecessary double handling of materials including roof trusses. The plots were not ready to receive the trusses and they had to be stowed on site rather than being erected ‘just-in-time’.

Plot Number


31

Figure 49: Build durations by plot number for timber frame erection

Supply chain issues There were some panels supplied to site by the timber frame manufacturer without openings or incorrectly placed openings. A first floor panel for plot 3 was delivered with an opening larger than the specified window as shown by Figures 50 and 51. This manufacturing error required other trades on site to make-up the missing section on site. There was also a missing window opening on a panel of plot 13.

Figure 50: Opening in timber frame larger Figure 51: Remedial work to panel on site than required opening for window

5.4.3 Roof construction The roof construction of plots 8 to 11 totalled 210 man-hours, averaging 55 man-hours per plot. This contrasts with plots 3 to 7 with an average of 18 man-hours per plot. The roof trusses for plots 8 to 11 arrived in two sections but not at he same time. Consequently, there was a delay to the erection of the

0 0.5

1 1.5

2 2.5

3 3.5

4 4.5

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

Plot Number

Num

ber o

f Wee

ks


complete roof trusses. Furthermore, the two part roof trusses required scaffolding to be erected that required added 45 man-hours. The transportation of the trusses to site was only possible in two sections.

Figure 52: Fixing roof trusses on plots 8 to 11 Figure 53: Roof trusses complete with two sections

The B type house design was the most challenging in regard to the construction process due to its design. Until the roof was completed the houses could not be made weathertight. Consequently there was water ingress into the living rooms on some of the B3 house type plots. There was also water ingress through the dormer windows until the roof tiling, weatherboarding and flashing was completed. The process also prolonged the time required for scaffolding on these plots.

Figure 54: Roof terrace construction on the B3 house Figure 55: Completing the dormer windows type

5.4.4 External skin

The external skin of the houses was constructed from a combination of brickwork, weather boarding and render. An average of 148 man-hours per plot was spent on the brickwork skin in contrast to an average of 63 man-hours for the weatherboarding and rendering combined. There were issues with the brickwork skin on some plots. 30 man-hours of repeat work was required on plot 12 to knock down and rebuild a section of the brickwork skin to the correct standard.


33

Figure 56: Rework to the brickwork skin. Plot 12 Figure 57: Brickwork completed on plots 6 and 7

Figure 58: Performance per plot for the brickwork skin

5.5 Bathroom pods

Accuracy problems with aligning bathroom pods with the timber frame resulted in additional dry lining work to plots 6 and 7. Most pods were delivered just-in-time but some double handling took place for some plots.


Figure 59: Unloading bathroom pods Figure 60: Bathroom pod not aligning with floor cassette

5.6 Internal works and finishes

The internals stage of the construction within this report includes the electrics and plumbing, internal walls and internal finishes. The dry lining and plastering required the most resource.

Figure 61: Man-hours per house type for superstructure construction (for each work package)

Design issues

Plots 8 to 11 (E type house), were originally constructed without a usable landing area by the window. However, this design was changed late in the construction process. The client decided that a landing was preferred, providing additional usable floor area, rather than an open hall space. The change in design increased the resource required for the plots including additional hours needed for plastering, decorating and installing the floor.

50

100

150

200

250

300

350

400

B A E

HOUSE TYPE

MA

N-H

OU

RS

Kitchen fitting

2nd fix carpentry 2nd electrical fix

1st fix electrical

2nd fix plumbing

1st fix plumbing

Dry lining/plastering


35

Figure 62: Landing area in E type houses 5.7 Waste measurement

The waste management at Beaufort Drive included the segregation of key waste products including timber, plasterboard and inert waste. This continued for most of the construction period except for the last month when only one skip was used on site and all material went into the single container.

Cement 7Ceramics 32Concrete 16Inert 8Insulation 20Metals 2Packaging 47Plaster 43Plastics 4Timber 56Total: 236

Figure 63: Breakdown of volume of waste produced for each product group

The four greatest amounts of waste products from the site were timber, packaging, plaster and ceramics. Despite using a factory produced panels, 56 m³ of timber waste was produced on site mainly from the temporary crash deck timber platforms used in the houses and forming part of the first floor until the stairs are installed were disposed of in the skips.

Packaging accounted for 47 m³ of waste on site. The packaging included cardboard, timber and plastic products. The timber bearers used for packing the timber frame panels during transportation contributed to the amount of waste produced on site. The other main source of timber packaging was the timber pallets used primarily for bricks and roof tiles.


43m³ of plaster waste was produced on site, 90% of this was plasterboard. Plasterboard waste arises on most sites due to the large quantities of plasterboard offcuts produced. This problem is due to the require-ment to cut the standard plasterboard panels to fit the dimensions of the interior walls and ceilings as well the ease with which the board can be damaged by water ingress, during transportation and storage and while handling on site. The volume of waste produced equates to two and half 1 m³ bags of plasterboard per house. This is typical for open panel timber frame house construction where all wall internal walls are boarded on site.

0

5

10

15

20

25

30

35

40

45

50

1st F

ix ca

rpentr

y

2nd f

ix ca

rpentr

y

Beams a

nd Bloc

k

Blockw

ork to

DPC

Brickw

ork

Draina

ge: Int

ernal

Dry lin

ing/ p

laster

ing

Externa

l Clad

ding

Felt and

Battenin

g

Flat ro

of

Floor fi

nishe

s

Floor s

creed

Insula

tion

Kitche

n fitti

ng

Main U

tilities

Raft fo

undati

ons

Rende

r

Roads

Roof T

russe

s

Site C

learance

Site H

andli

ng

Site w

orksTilin

g

Timber

frame

Trenchfi

ll fou

ndati

ons

Wall tilin

g

Window

s/ Doo

rs

InertCementPlasterMetalsInsulationCeramicsPlasticsTimberPackagingConcrete

Volu

me(

m3)

Figure 64: Volume of waste at Beaufort Drive by work package (for each product group)

Other than dry lining, the other main source of waste arises from the brickwork work package. The remedial work to brickwork created most of the brickwork waste.

Figure 65: Brick waste from remedial work Figure 66: Segregation of waste timber


37

0

20

40

60

80

100

120

140

160

Design

Specif

icatio

n

Method

s of W

ork

Miscell

aneo

us

reaso

nsNot

Define

d

Packa

ging

Projec

t

Manage

ment

short

coming

PlasterCementTimberPlasticsPackagingMetalsInsulationInertConcreteCeramics

Volu

me(

m3)

Figure 67: Volume of waste by cause of waste at Beaufort Drive (for each product group)

Despite the limited storage space and access restrictions, a site waste management plan was implemented that involved site segregation of the key waste products. Timber, plasterboard and inert waste were segregated on site before being removed from site to the waste transfer station.

Figure 68: Mixed waste skip Figure 69: Timber pallets


Figure 70: Timber waste after processing at the transfer station


39

6 Hereward Hall

6.1 Overall resource footprint Construction began on the Hereward Hall site in September 2006 and was completed in February 2008. The table in Figure 71 provides a summary of the labour resource that was invested in the houses constructed on the site. A comparison is made between the MMC houses using steel frame and the traditionally built homes.

The ICF houses required an average of 162 man-hours for the insulating concrete formwork superstructure (to construct the concrete formwork shell including the floor joists), and 611 man-hours for the scaffolding and external skin . The conventional brick and block plots required an average of 581 man-hours per plot for the brick and block cavity wall construction including external finishes.

Average number of man-hours

Construction elements Insulating Concrete Formwork (ICF)

Conventional brick and block construction

Insulating concrete formwork with floor joists and decking

162 N/A

Insulating concrete formwork with scaffolding, external skin, floor joists and decking

611 N/A

Brick and block cavity wall construction with floor joists, decking and external finishes

N/A 581

All works excluding infrastructure and site management

1,338 1,047

All works including infrastructure and site management

1,530 1,239

Figure 71: Comparison of resource requirements between insulating concrete formwork and traditional construction

Figures 72 and 73 show the average number of man-hours for the different house types for each construction type respectively. House type B was clearly the most resource intensive, particularly using the ICF method. However, the show homes were house type B and it is common for show homes to be more resource intensive.


Figure 72: Average number of man-hours per house type for ICF plots (for each build stage)

Figure 73: Average number of man-hours per house type for brick and block plots (for each build stage)

Resource footprints

Figures 74 and 75 show the average man-hours on site day over the course of the monitoring period for the ICF and conventional brick and block plots. The difference with the ICF resource timeline is clear. The resource utilisation for the traditional plots remained low until May and resource usage peaked in September. This is in contrast to the ICF plots where resource utilisation that started to reach the highest levels in March and continued into June before declining in August and September 2007.

0

200

400

600

800

1000

1200

1400

1600

1800

B A E

MAN-HOURS

HO

USE

TYP

E

Final finishes

Internals

Superstructure

Substructure

0

200

400

600

800

1,000

1,200

1,400

B A E

HOUSE TYPE

MA

N-H

OU

RS

Final finishes

Internals

Superstructure

Substructure


41

0

40

80

120

160

200

240

Sep 06

Oct 06

Nov 06

Dec 06

Jan 0

7

Feb 07

Mar 07

Apr 07

May 07

Jun 0

7Ju

l 07

Aug 07

Sep 07

Oct 07

Nov 07

Insulation installerWall and Floor TilerPainter and DecoratorDry Liner : FixerWater menElectricianPlumbersPlasterer: SolidRoof Slater and TilerCarpenterScaffolderICF InstallerBricklayerGround w orker

Num

ber o

f Man

-Hou

rs

Figure 74: Resource footprint for ICF plots over the course of the monitoring period

0

50

100

150

200

250

300

350

Oct 06

Nov 06

Dec 06

Jan 0

7

Feb 07

Mar 07

Apr 07 May

07 Jun 0

7Ju

l 07

Aug 07

Sep 07

Oct 07

Nov 07

Appliance f itterWall and Floor TilerPainter and DecoratorDry Liner : FixerWater menInsulation installerPlasterer: SolidElectricianRoof Slater and TilerPlumbersFloor screederScaf f olderCarpenterBricklay erFence InstallerGround worker

Num

ber

of M

an-H

ours

Figure 75: Resource footprint for the brick and block plots over the course of the monitoring period

6.2 Progress on site

The chart in Figure 76 shows the progress for the construction of all 35 units. The top half of the chart maps when work was being carried out on the 20 traditional plots and the bottom half shows the construction of the 15 ICF plots. The green shading shows the ground works, the red and grey shading shows the brick and block cavity wall construction and ICF respectively, and the light blue shading shows the internal works. The chart illustrates the following: • The substructures for all the plots were completed in the first four months of construction.


10

/02/

2006

10/0

9/20

06

10/1

6/20

06

10/2

3/20

06

10/3

0/20

06

11/0

6/20

06

11/1

3/20

06

11/2

0/20

06

11/2

7/20

06

12/0

4/20

06

12/1

1/20

06

12/1

8/20

06

CH

RIS

TMA

S

01/0

3/20

07

01/0

8/20

07

01/1

5/20

07

01/2

2/20

07

01/2

9/20

07

02/0

5/20

07

02/1

2/20

07

02/1

9/20

07

02/2

6/20

07

03/0

5/20

07

03/1

2/20

07

03/1

9/20

07

03/2

6/20

07

04/0

2/20

07

EAST

ER

04/1

0/20

07

04/1

6/20

07

04/2

3/20

07

05/0

1/20

07

05/0

8/20

07

05/1

4/20

07

05/2

1/20

07

05/2

9/20

07

06/0

4/20

07

06/1

1/20

07

06/1

8/20

07

06/2

5/20

07

07/0

2/20

07

07/0

9/20

07

07/1

6/20

07

07/2

3/20

07

07/3

0/20

07

08/0

6/20

07

08/1

3/20

07

08/2

2/20

07

08/2

8/20

07

09/0

3/20

07

09/1

0/20

07

09/1

7/20

07

09/2

4/20

07

10/0

1/20

07

10/0

8/20

07

10/1

5/20

07

10/2

2/20

07

10/2

9/20

07

Week No. 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63

Plot 028 0 0 0 0Plot 027Plot 026Plot 025Plot 024 0 0 0Plot 023 0 0 0 0Plot 022 0 0Plot 021 0 0 0Plot 020 0 0 0 0 1 2Plot 019 0 0 0 0 1Plot 018 0 0 0 0 0 1Plot 017 0 0 0 0 1 1Plot 016 0 0 0 0 2 2Plot 015 0 0 0 2Plot 014 0 0 0 0Plot 013 0 0 0Plot 009 0 0 0 0Plot 008 0 0 0 0 2 10Plot 002 0 2Plot 001 0 0 2

Plot 035 0 0 0 0 0 0 0 0 0 0 0 4 1 0 0 2 0 4 0 0 0 6 0 3 7 0Plot 034 0 0 0 0 0 0 0 0 0 2 0 4 0 1 1 3 4 0 0 1 0 0 0 2 0Plot 033 0 0 0 0 0 0 0 2 1 1 2 1 3 1 3 2 2 3 0 2 0 0 0Plot 032 0 0 0 0 0 0 0 0 0 0 0 0 0 0 3 2 0 0 1 0 0 0 0 1 3 2 5 3 2 2Plot 031 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 1 0 2 0 3 1 2 0 0 2 3 4 2 2 0Plot 030 0 0 0 0 0 0 0 0 0 0 0 2 4 0 0 0 1 3 0 5 0 0 1 5 1 0 0Plot 029 0 0 0 0 0 0 0 0 1 2 0 0 0 0 2 3 0 1 0 1 3 0 0 0Plot 007 0 0 0 0 0 0 0 0 0 0 2 3 2 0 5 2 0 2 2 6 1 0 0 2Plot 003 0 0 0 0 0 0 0 0 0 0 0 4 0 1 2 0 1 2 3 5 1 7 5 2 0 1Plot 012 0 0 0 0 0 0 0 2 3 0 0 0 4 0 0 2Plot 011 0 0 0 0 0 0 0 0 0 0 1 0 3 0 0 2Plot 010 0 0 0 0 0 0 0 0 0 7 1 8 0 2 0 0Plot 004 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0Plot 006 2 2 1 4 4 5 1 3 0 1 1 1 6 5 2 4 4 2 0 2 0 0 0 0 0 0 0Plot 005 1 1 3 7 11 5 3 9 2 1 3 8 4 2 5 5 2 0 2 0 0 0 0 0 2 0 0

Ground worksICFCavity wallInternals

Ground works

Insulated Concrete Forwork

Brick and block cavity wall construction

Internals

Internals

Figure 76: Progress chart showing when the main stages of the construction took place.


43

• The construction of the ICF plots started as planned but the houses were completed between three and five months later than planned.

• The construction of the traditional units started over 4 weeks later than planned but the plots were completed between four months and six months later than planned.

• The actual duration for the ICF superstructure construction ranged from 11 to 14 weeks per plot • The shorter ICF superstructure build duration did allow the roofs to be put on earlier allow and for

internal work on the critical path to begin sooner than for brick and block construction. • The actual duration for the conventional brick and block superstructure ranged from 23 to 28 weeks per plot • The resource usage for the brick and block superstructure peaked in June 2007, six months after the

planned peak in January 2007.

The issues discussed above are examined in further detail later in the report.

Site Management

Hereward Hall was a challenging site to manage. Managing two construction methods on site was difficult due to two different programmes. The site was not a ‘tight’ site to the same extent as Beaufort Drive but access was still restricted. The site shared an access road for a County Council office and a primary school. The shared access with the primary school restricted delivery times of materials that did have an impact on the efficiency of the construction process. The site was also restricted in regard to storage space, with most of the space at the back of the site. Unlike, Norwood Road that benefited from laying the permanent road surface in the early stages of construction, the Hereward Hall site used a site drainage system that did not allow the road to be completed until later in the construction process.

Once the scaffolding was erected for plots 3,4 and 7 materials could not be easily delivered on to site. Materials had to be unloaded by the forklift at the site entrance and then handled to the storage area for distribution later to other parts of the site. It is important to bear in mind these site specific constraints when considering the construction process and the related efficiency issues. A further issue was the high water table that made access to some areas of the site difficult, as discussed later in the report.

Figure 77: Waterlogged area of the site Figure 78: Waterlogged area of the site

6.3 Substructure

The 15 ICF houses were constructed using a trench fill foundation with blockwork to DPC supporting a Jetfloor composite flooring system that supports a structural concrete topping. The 20 conventional brick and block plots were constructed using beam and block floors supporting the floor screed.


Figure 79: Average number of man-hours per house type for ICF plot substructures for each work package

Figure 80: Average number of man-hours per house type for brick and block plot substructures for each work package

0

10

20

30

40

50

60

70

80

90

A B E

MA

N-H

OU

RS

0

10

20

30

40

50

60

70

80

90

100

A B E


Blockwork to DPC

Drainage - Internal / Local

Jetfloor

Structural concrete topping

HOUSE TYPE


Beam and block

Blockwork to DPC

Drainage - Internal / Local

Floor screed

HOUSE TYPE

MA

N-H

OU

RS


45

Figure 81: Performance per plot for substructure construction

Figure 76 illustrates that most of the substructure construction work was completed by February. However, remedial work was required on some plots to change the position of internal drainage and to add air bricks that were omitted from the brickwork below the DPC. This required return visits by the ground workers in July to undertake the remedial work.

Figure 82: Breaking out concrete floor in plot 7

6.4 Superstructure

6.4.1 ICF houses The construction of the site started with the construction of the ICF plots in October 2007. The work was carried out by the groundworks contractor whose operatives were trained on site to install the system. The progress is illustrated on Figures 74 and 78. The grey shaded area on Figure 83 shows the planned programme while the numbers show the number of operatives working on each plot each day. Most of the numbers are before or on the shaded areas. This indicates that in general, work was completed on or close to the planned programme. The last ICF superstructure was completed in April 2007.


Plot 4 was constructed first to ensure a show home was completed for the private sale plots. Most of the ICF superstructure for plot was completed in November and December.

Polarwall October November December January February March April

26 27 30 31 1 2 3 6 7 8 9 10 13 14 15 16 17 20 21 22 23 24 27 28 29 30 1 4 5 6 7 8 11 12 13 14 15 18 19 20 21 22 2 3 4 5 8 8 10 11 12 15 16 17 18 19 22 23 24 25 26 29 30 31 1 2 5 6 7 8 9 12 13 14 15 16 19 20 21 22 23 26 27 28 1 2 5 6 7 8 9 12 13 14 15 16 1 19 20 21 22 23 26 27 28 29 30 2 3

Plot 034 1 1 1 1 2 2 1 1 1 1 1 1 1 1 3 1 1 1

Plot 033 1 1 2 1 1 2 2 2 1 1 1 1 1 2

Plot 032 1 1 3 2 1 2 2 3 3 2 4 2 1 4 2

Plot 031 1 1 2 1 1 2 2 2 1

Plot 030 1 1 2 3 3 1 4 1 1 2 1 1 1 1 2

Plot 035 1 1 1 2 2 1 1 1 1 2 2 2 5 2 2

Plot 029 1 1 2 2 2 1 2 1 1 1 1 1 1

Plot 007 1 1 1 2 2 3 2 2 2 2 4 4 2 2 3 2 3

Plot 003 1 1 1 2 1 1 1 1 2 2 1 1 2

Plot 012 1 1 1 1 1 2 1 1 1 1 1 1 2 1 2 2 1 1 2 2 1 3 1 3

Plot 011 1 2 1 1 1 1 2 2 1 1 1 4 2 2 3 3 1 3

Plot 010 2 2 1 1 4 2 1 2 1 2 4 3 1 1 3 1

Plot 004 4 2 4 2 2 2 0 0 0 0 6 1 2 1 3 2 2 2 1 1 1 2 1

Figure 83: Planned programme against actual progress for ICF superstructure construction

Although operatives had to return to the plots to complete the gable ends following the erection of the roof trusses and to complete the roof terrace walls, the performance per work package chart shows non value added time below twenty percent on all plots.

Figure 84: Performance per location of the ICF work package (percentage of man-hours)

222 man-hours of non value added time was recorded for the insulating concrete formwork work package of which 35 man-hours of this time was recorded as repeat work. The main issues relating to performance are discussed in further detail in the subsequent sections.

Methods of work

The work was carried out a gang of groundworks operatives who were trained by the insulating concrete formwork manufacturer to install the system on site. There were some issues in the process including


47

remedial work. The main issue was with plot 10 where a blow-out during the concrete pour meant work had to be repeated on a section of the second floor wall accounting for 9 man-hours of non value added time.

Management

Rework to the window opening to the stairwell on plot 4 was carried out accounting for 12 man-hours of remedial work. The original opening was in the wrong position. A new opening was subsequently made in the ICF superstructure. The consequence of this was additional resource spent breaking out the concrete for the new opening, filling the existing opening and production of additional material waste.

Figure 85: Window opening broken out of plot 4

Figure 86: Average number of man-hours per house type for the superstructure construction of the ICF houses (for each work packages)

0

200

400

600

800

1000

1200

A B E

HOUSE TYPE

MAN-HOURS External cladding

Total roof

Brickwork

1st fix carpentry, pods & stairs ICF Installation

Scaffolding


6.4.2 Design Issues External skin

The ICF external skin of the ICF houses was constructed from a mix of brickwork, render and a tile hung finish. The tile hung finish predominated. • Despite requiring an average of 140 man-hours for construction the ICF superstructure (making up the

inner skin of the Polarwall houses), an average of 221 man-hours was required for the tile hung finish, 143 for the brickwork skin and 15 hours for the render totalling 379 man-hours. This is in contrast to the brick and blocks plots that had an average of 86 man-hours per plot for the tile hung finish.

• The tile hung finish was a very resource intensive process because of the requirement for a double layer of counter battening. The gable ends are particularly resource intensive because of the additional cutting requirements for the tiles.

Brickwork skin Render Tile hung

143 15 222

Figure 87: Average number of man-hours per plot for external finishes on the ICF plots

Figure 88: Double layer of batten and counter batten fixed to insulating formwork for tile hung finish Roof terraces

The construction of house type B designed with a roof terrace was the most challenging. A major issue was achieving a watertight internal space. This was not achieved on plots 4, 5 and 6 resulting in remedial works to the internal finishes. Remedial work to the boarding, plastering and decorating accounting for an average 16 man-hours of non value added time per plot. The later stages of the construction process for these plots saw a significant increase in non value added time as indicated by Figure 92 showing the daily performance on site. Snagging and remedial work resulted in non value added time between 20 and 40% most days.

The main issue was water ingress into the living room of these units before the roof terrace was waterproofed as illustrated by Figure 91. The construction of roof terrace on the ICF plots was more complex than the concrete multideck system used on the steel frame units on Norwood Road. It took longer on Hereward Hall to gain a weather tight structure.


49

Figure 89: Completed roof terrace Figure 90: Damage to living room from water ingress during construction

-100%

-80%

-60%

-40%

-20%

0%

20%

40%

60%

80%

100%

02/10

/06

17/10

/06

09/11

/06

05/12

/06

30/01

/07

19/02

/07

06/03

/07

21/03

/07

05/04

/07

24/04

/07

11/05

/07

29/05

/07

15/06

/07

29/08

/07

Added Value SupportStatutoryNon Added ValueAdded ValueP

erce

ntag

e of

Man

Hou

rs

Figure 91: Daily performance for plots 4, 5 and 6

6.4.3 Brick and block cavity wall construction The other 20 units were constructed using conventional brick and block cavity construction and finished with the same external finishes as the ICF houses. However, the tile hung finish did not require the extensive counter battening used on the ICF houses.

The main trends in the data are: • The average number of man-hours per plot for the brickwork and blockwork was 343 man-hours • 806 man-hours of non value added time has recorded on the conventional brick and block plots of

which 265 man-hours have been non value added time. • 423 man-hours were lost on site during construction due to inclement weather that had the greatest

impact on the productivity of the bricklayers. • Most of the foundations for the houses were completed by the end of January 2007. However, the resource

usage for the cavity wall construction was very low in the following 3 months as shown by Figure 85. • Repeat work was required on some plots due to damage by high winds in January and February 2007.


Figure 92: Construction of plots 23 to 28 Figure 93: Construction of plots 13 to 22

Figure 94: Average number of man-hours per house type for brick and block house superstructure (for each work package)

0

100

200

300

400

500

600

700

800

900

A B EHOUSE TYPE

MA

N-

HO

UR

S

External claddingTotal roof

1st fix carpentry, stairs and podsBrickwork Scaffolding


51

0

2

4

6

8

10

12

14

16

18

Nov Dec Jan

Feb Mar AprMay Ju

n Jul

Aug Sep Oct

Num

ber

of O

pera

tives

Figure 95: Bricklayers on site per day for the construction of the traditional houses

0

4

8

12

16

20

Oct Nov Dec Jan

Feb Mar AprMay Ju

n Jul

Num

ber

of O

pera

tives

Figure 96: Bricklayers on site per day working on the brickwork skin for the ICF houses

6.5 Bathroom pods

Bathroom pods were used on all 35 plots. In general, they were delivered and installed without any major issues. The main issue was the double handling required for some houses, particularly the traditional houses, because just-in-time delivery was not implemented. The pods came in larger deliveries and were ahead of schedule for most of the traditional brick and block plots. Therefore, they were stored on site and double handled on site until they were ready for craning into position. In contrast, coordination of the crane hire with delivery of the pods meant there were delays on occasion to delivery of the pods.


Figure 97: Bathroom pods for the brick and block plots stored on site

Figure 98: Bathroom pods on the brick and block plots Figure 99: Bathroom pod in ICF plot

6.6 Internal works

The internal works on all dwellings took over 25 weeks as illustrated by Figure 76 with some lasting over 36 weeks. Multiple trade visits by internal trades and trades completing the cladding were required to complete the houses. 769 man-hours of non value added time was recorded for remedial work on site. Most of this remedial work was for carpentry and dry lining works. The types of issues contributing to this non value added time included: • Repeat work to internal finishes due to water ingress • Snagging works to complete the internal finishes to the required standard for the client.

6.7 Waste measurement

Hereward Hall had the highest volume of waste recorded per plot of the three sites. A total of 710 m³ of waste was recorded that equates to 20 m³ of waste per plot. The main waste products produced on the Hereward Hall site were packaging, timber, plaster and insulation.


53

Figure 101: Waste produced during the monitoring period by product group (m³)

Packaging accounts for 209 m³ of waste and included plastic wrapping, cardboard and timber pallets.

Timber accounted for 125m³ of the waste produced on site. 29m³ of this waste was MDF and 25 m³ was softwood both used for the second fix carpentry finishes.

Insulation waste was high with 78 m³ waste produced. A third of this waste was from offcuts from the insulating concrete formwork assembly and from the plumbing and electrical installation. Most of this waste was segregated from other waste on site and removed by the supplier for recycling.

0

40

80

120

160

200

Blockw

ork to

DPC

Brick/B

lockw

ork

Carpen

try 1st

fix

Carpen

try 2nd

fix

Concre

te top

ping

Draina

ge - In

terna

l

Dry lin

ing

Felt, b

atten

and

tilingFit C

arpet

Floors

ICF In

stalla

tion

Insula

tion

Jetflo

or

Mains u

tilities

Paintin

g

Rende

ring

Roof T

russe

s

Site H

andli

ng

Vertica

l Tilin

g

Window

s \ D

oors

FurnitureMetalsPlasticsTimberInsulationCeramicsCementPlasterPackagingConcrete

Volu

me(

m3)

Figure 102: Volume of waste produced per work package (for each product group) in m³

Cement 25Ceramics 71Concrete 77Furniture 3Insulation 78Metals 18Packaging 209Plaster 81Plastics 23Timber 125Total: 710


Figure 103: Segregated insulation waste from the Figure 104: Plasterboard waste on site insulating concrete formwork

The main sources of waste were the brickwork and blockwork, the dry lining and the second fix carpentry. Site handling is also very high that refers to packaging waste from a number of different work packages. A large proportion of the waste was offcuts produced as a result of work methods that require materials to be cut to size on site. Packaging was also a major cause of waste.

Figure 105: Cause of waste produced for each product group


55

7 Norwood Road

This chapter presents the findings from the measurement process on the Norwood Road site. The site is the largest of three sites and was completed before the other two. The site benefited from a one-way access route through the site that enabled efficient delivery and distribution of materials, unlike the other two sites which had restricted access.

7.1 Overall resource footprint

The table in Figure 106 provides a summary of the labour resource that was invested in the houses constructed on the site. A comparison is made between the superstructure construction of the light gauge steel frame houses and the conventional brick and block homes. The comparison is average of all house types. Averages for each house type at each stage of the construction are provided later in the report.

Average number of man-hours

Construction elements Light gauge steel frame panels

Brick and block cavity construction

Light gauge steel frame panel and floor cassette erection

51 166

Brick and block cavity wall construction with floor joists and decking

Brick and block cavity wall construction with floor joists, decking, scaffolding and external finishes

N/A

N/A

354

491

Light gauge steel frame superstructure including scaffolding, brickwork skin and external finishes

272 N/A

All works excluding infrastructure and site management

842 1,095

Figure 106: Comparison of labour resource utilisation on site between light gauge steel frame and conventional brick and block construction

The light gauge steel frame units required an average resource input of 51 man hours to erect the frames including the floor cassettes and 272 man-hours per plot for the steel frame and external skin. In contrast, the average number of man-hours invested on the traditional units was 354 man-hours for the cavity wall construction and the floor construction and 491 man-hours including the external finishes and scaffolding.

The average overall resource input excluding site management and infrastructure works was 842 man-hours for the steel frame units and 1,095 man-hours for the traditional units, a difference of 350 man-hours. An average of 1,000 man-hours per plot is typical for a conventional brick and block dwelling of similar size and style to those constructed on the SmartLIFE project.


0

100

200

300

400

500

600

700

800

29/09

/06

16/10

/06

02/11

/06

17/11

/06

04/12

/06

19/12

/06

15/01

/07

30/01

/07

14/02

/07

01/03

/07

16/03

/07

02/04

/07

19/04

/07

04/05

/07

22/05

/07

07/06

/07

22/06

/07

10/07

/07

25/07

/07

09/08

/07

Appliance FitterGlazierLandscaperMasticFloor FinisherCleanerRendersWall and Floor TilerInsulation installerPainter and DecoratorElectriciansPlasterer: SolidPlumberRoof Slater and TilerSite LabourerDriver - craneCarpenter and JoinerScreederScaffolderForkLift DriverBeam and blockEngineerSteel frame erectorBrickLayerGroundworkerFence InstallerDriver - DiggerDriver - 360

Num

ber

of M

an-H

ours

Figure 107: Resource footprint for the duration of the construction period at Norwood Road showing the average number of man-hours per day (for each trade)

7.2 Progress on site Figure 108 shows the weekly progress for the main stages at Norwood Road. • The construction of the houses at Norwood Road ran closer to programme than on the other sites but

construction did last longer than the planned programme. • The duration for the construction of the steel frame dwellings ranged from 31 to 34 weeks • The duration of the construction of the conventional brick and blocks dwellings ranged from 35 to 41 weeks • The steel frame construction was completed in smaller blocks than the cavity wall construction for the

conventional build that was taking place on up to 18 plots at one time. • Getting the roof on quickly was more easily achieved with the light gauge steel frame houses as

indicated by the grey shading on the chart. • The internal works started on the steel frame dwellings between 7 and 12 weeks before the conventional

dwellings but the dwellings were completed, both steel and conventional, at the same time.

WEEKLY PROGRESS FOR MAIN STAGES NORWOOD RD

Date November December January February March April May June July August

Plot Nos 16 23 30 6 13 20 27 4 11 18 1 8 15 22 29 5 12 19 26 5 12 19 26 2 9 16 23 30 7 14 21 28 4 11 18 25 2 9 16 23 30 6 13 20 27

454647484952515056555453343332313029282726

34125 6 789

1011121314151644433536374142403938252423222120191817

Substructure

Cavity wall superstructure

Roof covering

Internals and final finishes

Substructure

Light gauge steel frame

Roof construction

External skin, internsl and final finishes

Figure 108: Actual progress chart show the durations of the construction for both the steel frame and conventional plots


7.3 Substructure

The Norwood Road site used two substructures construction methods. Trench fill foundations were used for most of the plots combined with a beam and block floor for the traditional brick and blocks plots and a Jetfloor floor for the steel frame plots. However, due to archaeological remains found during site investigations, raft foundations were used under some plots to avoid unnecessary disturbance to the ground. The raft foundations were combined with a structural concrete topping.

Figure 109: Process map for foundation using trench fill footing with beam and block floor and floor screed

Figure 110: Process map for foundation combining trench fill with Jetfloor and structural concrete topping

Figure 111: Process map for foundation combining raft foundation with structural concrete topping

The average man-hour resource footprint charts below compares the traditional brick and block construction with the steel frame construction. They also compare house types and construction methods as described in the previous section.

Ground Foundations Drainage Beam and blockWorks Setting out Excavate Backfill Concrete beams Blocks

excavate Backfill Grout Screed pour concrete

Drainage Run drains

Bricklaying Block to dpc

Complete Splash courseBlock to dpc

Ground Foundations Drainage Jet FloorWorks Setting out Excavate Backfill Concrete beams Insulation

excavate Backfill Steel shuttering Concrete foot Concrete topping

Drainage Run drains

Bricklaying Block to dpc

Complete Splash courseBlock to dpc

Ground Foundations Raft (Block) (Plot) Works Setting out Backfill Steel mesh Steel shuttering

Stone base Backfill Steel shuttering Insulation ReinforcementConcrete blind Concrete Concrete topping

Drainage Run drains

Bricklaying Block to dpc Complete Splash courseBlock to dpc


59

Figure 112: Average man-hours per house type for substructure construction of the conventional brick and block plots (for each work package)

JETFLOOR FOUNDATIONS-MAIN PACKAGES

0

20

40

60

80

100

120

17 18 19 20 21 22 23 24 25 37 36 35 43 44 16 15 14 13 12 11 10 9 8 2 1

PLOTS IN SEQUENCE

MA

N-H

OU

RS

Structural ConcreteToppingJetfloor system

Drainage - Internal /LocalBlockwork to DPC

Foundations

Figure 113: Sub-structure man-hours per plot for steel frame plots for each work package

7.4 Superstructure

7.4.1 Light gauge steel frame erection The construction of the superstructures began with plots 17 to 25, the first block of steel frame plots.

0

10

20

30

40

50

60

70

80

90

A B B4 (4 bedroom)

MA

N-H

OU

RS

Floor screedInstall beam and block floor Drainage - Internal / Local Blockwork to DPC Footings

HOUSE TYPE


Figure 114: Average man-hours per house type for superstructure construction of steel frame plots (for each work package)

The most resource intensive plots were the B type houses. These are the larger dwellings with three bedrooms and they incorporate a roof terrace. The steel frame panel erection took proportionally longer on these large dwellings. On average, 51 man-hours were required per plot. The main resource requirement was the brickwork skin with over 250 man-hours required for the B type houses. The man-hours required for the external finishes were also longer, due to the large area of finishes on B type houses including the roof terraces.

A total of 3,907 man-hours of non value added time were recorded during the construction of the light gauge steel frame houses. 297 man-hours of this total was non value added time directly part of the steel frame erection work package while there were also issues with the steel frame and brickwork skin interface.

Design

The design information required was not forwarded to the subcontractor erecting the steel frame. Therefore, the membrane between the floor and the steel panel on the first block of plots was omitted. The omission of the design detailing for this meant some remedial work was required (i.e unscrewing the anchor bolts to lift the ground floor panels and inserting the membrane. This accounted for 64 man-hours of non value added time for plots 17 25 (7 man-hours per plot).

Figure 115: Steel panels arriving on site Figure 116: Retrofitting of membrane under ground floor panels


61

Methods of work

The main issues was the interface between the brickwork skin and the steel frame panels. • 46 man-hours of non value added time to correct opening sizes in brickwork for windows and doors.

Some of this work was completed by bricklayers while some was completed by carpenters fitting windows and doors.

7.4.2 Conventional brick and block construction

The conventional brick and block construction began with the construction of plots 26 to 34, the 4 bedroom detached houses. for the dwellings constructed using brick and block cavity wall construction began with plots 26 to 34. Figure below compares the average number of man-hours per house type for the brick and block plots. The A2 house type average is higher than the equivalent for the light gauge steel frame but the B3 house types are both lower than the light gauge steel frame plots.

Figure 117: Average man-hours per house type for superstructure construction of brick and block plots (for each work package)

Methods of work

A total of 530 man-hours was recorded as non valued added time for the brick and blockwork work package, of which 351 of man-hours were recorded as non value added time due to repeat work. Although generally the site was able to resource enough bricklayers there were issues building to the required quality. The main contractor has a local labour requirement policy that meant there was a dependence on labour from the local area. It appears that local bricklayers are less willing to work overtime. This restricted the hours per day that could be achieved hence the build duration. Moreover, there was an issue with the quality of the work delivered resulting in 5% of time on site spent on remedial work. Figure 110 clearly shows the period between May and August with a higher percentage of non value added time. This is a result of the hours spent returning to plots to undertake remedial work. The key issues are discussed further in the following sections.

0

100

200

300

400

500

600

700

800

A B B4 (4 bedroom)

MA

N-H

OU

RS Scaffolding

External finishes Total roof

Brickwork/blockwork

HOUSE TYPE

1st fix carpentry, stairs and pods


Figure 118: Performance chart showing percentage change in average non value added time for the brickwork and blockwork per month

Specific issues included: • A significantly slower and more resource intensive process than the steel frame erection accounting for

more man-hours per plot to construct. • Specific issues that required repeat work included:

o Rework to the size of window openings on accounted for 131 man-hours. Some of this was attributed to the use of an apprentice bricklayer who made mistakes that had to be corrected.

o Retrofitting cavity wall insulation and cavity closers accounted for 101 man-hours

Figure 119: Window fitted following remedial work to the opening Building to the required tolerances was an issue with some of the houses. This was demonstrated on site with the requirement to cut timber joists to length. The joists were designed 30 mm too large on each unit for tolerance, and the adjustments were made on site with the allowed limits The cutting of joists required up to two hours per plot which equated to 42 man-hours for all plots.


63

Figure 120: Cutting the posi-joists on site

Supply chain The supply of one of the facing bricks for the site was inadequate to complete the entire job. Therefore, a different facing brick type was used for some units and brick tinting was used to produce the final finish. Additional hours were spent on this tinting process. More importantly though, consistency in quality was not achieved due to the problems managing the supply chain for this particular product. Design The B house types were the most challenging in regard to the construction process due to the roof terraces. This house type required scaffolding for longer than other house types to allow for completion of the terrace including the overhang detail and temporary safety rails. In addition remedial work was carried on some plots including interfaces between the window and the roof terrace. This non value added time contributed a high proportion of the overall non value added time in July shown on Figure 30.

Figure 121: View of site during the roof construction Figure 122: Remedial work for roof terrace of the brick and block plots and window opening interface on house type B3


Figure 123: Roof terrace construction house Type B Figure 124: Roof terrace nearing completion

The steel frame dwellings with the fast build time were the first to complete the roof construction enabling internal works to begin. A predominantly horizontal approach to construction of the steel frame dwellings meant the steel frame was erected for a small number of dwellings followed shortly afterwards by the roof construction. The roof trusses for plots 17 to 25, were fixed in late December 2006. Unfortunately, due to supply chain problems they were delivered too late for the tiling to be completed before the Christmas break. High winds during the Christmas break damaged the trusses and remedial work was required before the tiling could start.

Other issues were the delay in achieving a watertight shell on the A type houses. There were delays in finalising the design of the valley gutters on plots 17,18, 24, 25, 36 and 37. Until a decision was made water ingress was a problem resulting in remedial work to the decorating later in the process. Over 60 man-hours of remedial work were carried on these plots due to delay in finalising the valley gutter designs.

Unlike on the other SmartLIFE sites though, the roof terraces on the B type houses have not posed the same problems with water ingress due to the use of the multideck floor constructed with concrete that was installed earlier in the construction process.

7.4.3 Bathroom pods The bathroom pod installation started on the steel frame plots. Most pods were installed just-in-time from the delivery lorry on to the allocated plot. The main issues in the process were: • Remedial work to the wiring for the extractor fans on some pods. Two man-hours per pod were

required for this work. • Remedial work to window opening on one pod to change the window opening.


65

Figure 125: Bathroom pod in position Figure 126: Bathroom pods on plots 29 to 32

7.5 Internals

The internal fit-out of the dwellings commenced with plots 17 to 25 in January 2007. The first dwellings were inhabited in June 2007. A minimum of 270 man-hours was required per house type for the internal works with some house types requiring over 300 man-hours with both construction methods.

Figure 127: Average number of man-hours per house type for internal works in steel frame plots (for each work package)

0

50

100

150

200

250

300

350

A B E

MAN-HOURS

1st fix plumbing 2nd fix plumbingElectrical first fix Electrical second fix

Plastering/ drylining2nd fix carpentry Kitchen fitting

HOUSE TYPE


Figure 128: Average man-hours per house type for internal works in brick and block plots (for each work package)

Design changes

Plots 19-23 were the first light gauge steel frame houses to be constructed. The master bedroom design for these plots (house types E) had a window between the master bedroom and the hall. This design was subsequently changed due to health and safety concerns and units 41 to 42 underwent remedial work to close the openings accounting for 6 man-hours per plot. This contributed to the higher number of man-hours required for this house type.

Figure 129: Dry lining opening in the bedroom

0

50

100

150

200

250

300

350

400

A B B4

MAN-HOURS 1st fix plumbing 2nd fix plumbing

Electrical first fix Electrical second fix

Plastering/ drylining2nd fix carpentry Kitchen fitting

HOUSE TYPE


67

7.6 Final finishes

The internal finishes were completed on the B4 and A house types during the monitoring period but not for some house Type B. Therefore, the man-hour averages are lower for house type B. The resource required for the B4 house types is significantly higher than was expected because there were more bedrooms and a larger surface area. The 4 bed houses all had downstairs shower rooms that required tiling, also contributing to the higher average number of man-hours.

Figure 130: Average man-hours per house type for final finishes for steel frame plots

The average number of man-hours per house type for the final finishes for both construction methods ranged from 48 to 116 man-hours. Some plots were still being completed after the full time monitoring period on site ceased therefore some average are very low. Further explanation is provided in Section 8.1 on data limitations.

0

20

40

60

80

100

120

A B B4

MAN-HOURS

HOUSE TYPE

Cleaning

Floor Finishes Painting

Wall tiling


Figure 131: Average man-hours per house type for final finishes for conventional brick and block plots

Figure 132: Downstairs shower room

0

20

40

60

80

100

120

A B E

MAN-HOURS

HOUSE TYPES

Cleaning

Floor FinishesPainting

Wall tiling


69

7.7 Waste measurement The total volume of waste recorded for the Norwood Road site was 879 m³. This equates to an average of 15.7m³ of waste per plot or just over two and half builders skips (6 m³) of waste per dwelling.

Cement 35Ceramics 187Concrete 138Electrical Equipment 10Furniture 2Inert 6Insulation 102Metals 2Packaging 110Plaster 132Plastics 3Timber 153Total: 879

Figure 133: Breakdown of waste produced on site by product group

The top five waste products were ceramics, timber, concrete, plaster and packaging.

Bricks and blocks

Figure 133 shows over 400m³ of waste recorded from the brickwork and blockwork work package: • 187m³ of ceramic waste, of which over 90% was bricks, • 138 m³ of concrete block and lintel waste.

The amount of remedial work required for the brick and block cavity wall was discussed earlier in the report. There was an increase in ‘waste’ not only in man-hours of non value added time but also in volume of waste material waste.

A further issue was the ‘tidy site’ policy implemented by the site management. This involved regular house-keeping sessions on site whereby materials including bricks, blocks and lintels, both waste and new, were disposed of to tidy work areas. This was deemed necessary to maintain health and safety standards on site. New bricks and blocks were disposed of if not tidied at the work place.

There are major opportunities for improvement in the waste management. One of the key constraints is the lack of waste management throughout the whole supply chain. Materials come to site, they are unloaded and then the supplier leaves site without taking any further responsibility for waste materials arising from damage or packaging used for transportation and material protection.


0

50

100

150

200

250

300

350

400

450

1st F

ix ca

rpentr

y

2nd f

ix ca

rpentr

y

2nd f

ix plu

mbing

Blockw

ork to

DPC

Brickw

ork/Bloc

kwork

Draina

ge - In

terna

l

Floor F

inishes

Floor J

oists

Floor s

creed

Insula

tion

Jetflo

or sy

stem

Kitche

n fitti

ng

Loft I

nsula

tion

Paintin

g

Plasterin

g/ Dryl

ining

Raft Fou

ndati

ons

Road C

onstr

uctio

n

Roof ti

ling

Roof T

russe

s

Site H

andli

ng

Steel fra

me pan

els

Electrical EquipmentPlasterMetalsInertFurniturePlasticsInsulationCementConcreteCeramicsTimberPackaging

Volu

me(

m3)

Figure 134: Waste produced per work package for eachproduct group Packaging

110m³ of waste packaging was produced on site. Packaging is one of the major waste categories and includes timber pallets, polythene around bricks and lightweight blocks, and wrapping around internal joinery including kitchen units, doors and other fixtures. Timber pallets were one of the main waste products.

Figure 135: Timber pallets disposed of in the skip

Insulation

The amount of insulation waste on site was surprisingly high. The main contributor to this was the Jetfloor insulation. Windy weather in January caused damage to a large delivery of Jetfloor insulation stored on site. This resulted in the disposal of 25 m³ of insulation waste in one day.


71

Plasterboard

Second to brick waste, plasterboard was one of the main waste products produced on site. 108 m³ of plasterboard waste was recorded. Most of the offcuts were segregated in 1 m³ bags provided by the supplier for removal from site to the supplier’s recycling facility. However, in the later stages of the project, plasterboard was not segregated and disposed of as mixed waste. Consequently, waste was sent directly to the waste transfer station for segregation.

Figure 136: Plasterboard, bagged and segregated Figure 137: Brick, block and mortar waste being removed from site .

Figure 138: Mixed waste on site during the later Figure 139: Mixed waste being segregated at stages of the project the waste transfer station


8 Conclusions

8.1 Data limitations

The data collection involved two main methodologies, CaliBRE and SMARTAudit. These are intensive data collection methodologies. CaliBRE involves activity sampling and with a dedicated data site observer working full time to collect the data.

Although there were only three main house plan forms, variations in external finishes and internal layouts made it difficult for the assembly teams to achieve a learning curve. Often the next plot in sequence had a new set of drawings and specifications. Even terraces had variations for end of terraces and elevations which change in finish from house to house.

Data collection on site continued to the end of August for the Norwood Road and Beaufort Drive sites. Data collection continued until the end of September for the Hereward Hall and on a full time basis with monitoring take place on a part-time basis until February 2008 on Hereward Hall. This had the following implications:

Beaufort Drive

A complete data set was not obtained for the final finishes and external skin for some plots particularly house type A.

Hereward Hall

A complete data set was not obtained for: • The final finishes using the insulating concrete formwork. • The internal works, final finishes and external finishes for plots using the conventional brick and block.

Norwood Road

A complete data set was not obtained for: • The final finishes for the A and B house types for conventional and brick and block construction and the

A house types for the light gauge steel frame. • The external finishes for the B house types for the conventional brick and block construction.

8.2 Beaufort Drive

The following conclusions can be drawn from the performance measurement of Beaufort Drive: • Inaccuracy in the substructure construction in both the design process and in the work method

increased the resource requirements and delayed the construction process. • The ‘tight’ site restricted site access and the number of different trades working on site at the same time

therefore extending the build duration for some work packages. • The timber frame system was not used to its full potential. Firstly, the design of some plots did not allow

for the roof to be installed quickly. Secondly, a horizontal rather a vertical approach to the timber frame


73

and roof installation meant multiple plots were under construction at the same time rather than sequentially to allow other trades to start work on site sooner.

• When the substructures were not handed over to the timber frame contractor as designed due to design accuracy issues, the timber frame erection was slow and inefficient. When the substructures were constructed correctly the timber frame erection process was faster and more efficient.

• Bathroom pods were used but just-in-time delivery was not implemented. The number of deliveries to site was restricted to site and therefore some pods were stored on site creating the need for double handling.

• There are a number of key opportunities for improvement with waste management particularly with managing the supply chain and controlling quality on site. Returning packaging to the manufacturers could be increased. Controlling quality on site, particularly in the brickwork could have reduced the volume of waste being removed from site.

8.3 Hereward Hall

The Hereward Wall site combining both traditional and ICF construction methods proved to be the most challenging site in regard to the construction process. The main findings have been: • Construction took between 4 and 6 months longer than the planned programme • The resource used for the conventional brick and block plots remained very low until late into the project.

This was particular noticeable when comparing the number of bricklayers on the Hereward Hall site with numbers on the Norwood Road site.

• The superstructures for the ICF houses required more that 100 man-hours less labour resources to build than the traditional brick and block superstructures.

• Certain design features including the roof terrace for house type B made the construction process difficult. Internal works were damaged due to water ingress and remedial work being carried to the internal finishes.

• Hereward Hall had the highest proportion of non value added time of three sites. The main causes of this were double handling time due to the site layout with site storage restricted to one main storage area and remedial work required to gain the required quality of product for completion.

• Site waste management was organised at stages in the project including site based segregation of timber, plasterboard, ICF insulation and inert waste. However, in the later stages of the project this process was not carried out and waste was not segregated.

8.4 Norwood Road

• Both the conventional brick and block and the light gauge steel frame houses had lower resource requirements than equivalent house types on the other sites.

• Houses of both systems were built closer to programme than the other sites. • Quality of the brickwork was an issue for the brickwork skin of the light gauge steel frame units and for

the cavity wall construction for the traditional units • The site setup including the early road construction and one-way traffic management made the site

more efficient to run. • Site waste management was organised at stages in the project including site based segregation of

timber, plasterboard, and inert waste. However, in the later stages of the project this process was not carried out and waste was not segregated.


8.5 Lessons Learnt

The report has highlighted some of the main issues that have been recording from undertaking the site measurement. These issues are summarised in the ‘Lessons Learnt’ table below. The issues are categorised in relation to common themes for comparison between modern methods of construction and conventional brick and block construction. Reference to the relevant section in the report where further explanation is provided is made in the table. Some are ‘opportunities for improvement’ because changes to design, work methods, supply and or project management could reduce the ‘waste’ that occurred in the process.

Construction

method

Issues

Timber frame

Beaufort Drive

Insulating concrete formwork

Hereward Hall

Brick and block

Hereward Hall

Light gauge steel frame

Norwood Road

Brick and block

Norwood Road

Buildability Complex roof design for E type with two sections (5.4.2)

B type longer to get weathertight (5.4.3)

B type took longer to get weathertight (6.4.2)

Resource intensive tile hung finish (6.4.2)

B type took longer to get weathertight

Valley gutter A type house delayed achieving weathertight shell (7.4.2)

B type longer to get weathertight

Man-hours required for superstructure lowest on A and E type houses (5.4.1, 6.4.1 and 7.4.1) Build time

Longer than programme (5.2)


Significantly longer than programme (6.2)



Number and duration of trade visits

Multiple visits for internal trades (5.2)


Multiple visits for internal trades (6.2 and 6.6)



Accuracy and timeliness of foundations

Repeat work to ensure correct interface of sole plates and drainage (5.3.3)

On programme

Remedial work to blockwork to DPC to add air bricks and change drainage position (6.3)

Long build duration

Closer to programme than other sites (7.2)

Closer to programme than other sites (7.2)

Predictability Ground conditions for some plots made planning difficult (5.3)

More predictable than brick and block (6.2)

Major delays. Bricklayer resources low (6.4.3)

Steel frame shell was close to programme (7.2).

Need for scaffolding

Required for long duration with adjustments particularly for B type (5.4.3)

Required for long duration with adjustments particularly for B type houses and for tile hung finish (6.4.2)

Required for long duration.

Required for long duration with adjustments particularly B type

Required for long duration with adjustments particularly B type


75

Design issues

i) Complexity of roofscape

ii) Design variations

Roof terraces of B type (5.4.3)

Roof trusses on E type (5.4.2)

Landing design change on E type (5.6)

Roof terraces (6.4.2)

Landing design change on E type

Roof terraces (6.4.2)

Landing design change on E type

Roof terraces

Valley gutters (7.4.2)

Interior landing window (7.5)

Roof terraces

Management Issues

‘Tight’ site made site difficult to manage (5.1)

Horizontal build process, interface with different trades difficult (5.4.2)

Two methods, high water table and site access made the site difficult to manage (6.2)

Early infrastructure works required to combat high water table (7)

One way system of site circulation worked well

Early infrastructure works required to combat high water table

One way system of site access worked well

Supply chain issues

Just-in-time

Factory process

Most of the pods delivered just-in-time (5.5)

Incorrect window opening (5.4.2)

Most of the pods delivered just-in-time (6.5)

Storing and double handling some bathroom pods (6.5)

Most of the pods delivered just-in time. Some remedial work to extractor fan wiring and windows.

Storing and double handling some bathroom pods (7.4.3)

Work method issues

Trade skills

Repeat work high for the bricklaying g for the brickwork skin (5.4.4)

Ground workers without experience of ICF used (6.4.1)

Repeat work for brick and blockwork (6.4.3)


Dependence on local labour including apprentice brick layer


Dependence on local labour including apprentice brick layer

Waste management

Segregated materials (plasterboard, timber and inert waste) for most of build duration (5.7)

Segregation not carried out in last two months

High plasterboard and packaging waste volumes

Segregated timber, plasterboard, inert waste and insulation from insulating concrete formwork (6.7)

Segregation not carried out in last 6 months

High packaging, timber and plasterboard waste volumes

Segregated materials for most of build duration but only mixed waste in last two months (7.7)

High volumes of brick and block waste, plasterboard, timber and packaging


Appendix A: CaliBRE Performance Measurement Toolkit

The performance measurement tool used is named CALIBRE and was developed by BRE from extensive experience gained by the BRE over the past thirty year of the measurement and productivity assessment of housing. The CALIBRE monitoring process is simple to use and is undertaken without interfering with the task being undertaken. The measurement process can undertaken by an observer, often an undergraduate or recently graduated trainee who can gain a thorough understanding of the construction process.

The process has four main elements, namely: • Mapping the construction process • Identifying and coding the packages and tasks • Monitoring the site and factory construction process • Analysis, reporting and feedback

Typically the monitoring and feedback is undertaken continuously from the moment the first operatives set foot on site to the last operative leaving site. Comprehensive training is provided to bring each observer up to the same high level of understanding, with a full time back up being provided by the BRE. All software and hardware essential for the monitoring process is provided along with technical support from the BRE.

For each observation, the observer records five attributes:

What each operative is doing to Which element or work package. Where each task is being carried out. Who each operative is and When the observer undertook the observation round

The packages of work and task codes are allocated according to a BRE developed National Work Breakdown Structure. These codes take into account the nature of the construction works, the levels of observed and mapped detail that are achievable and the need for code consistency between different projects. The coding system is sufficiently flexible for additional codes to be added when unforeseen tasks are observed as construction proceeds. Work monitored is categorised as Added Value Time, Support Time, Statutory Time or Non value added Time.

• Added Value Time is expended by operatives or plant on those activities that directly add value to the construction being undertaken.

• Support Time is spent on activities, which directly support Added Value activities.

• Statutory Time is time expended by operatives that support legislation or regulations

• Non value added Time is time expended which adds no value to the project


77

• Using the categories above observers monitor operatives activities on site by making regular

rounds of the site throughout the day. • Every round involves inputting the activity of each operative and as well as plant into a hand-held

computer (PDA). The PDA is equipped with Access that allows data to be input into a database. • At the end of each day the data is downloaded from the PDA to a laptop or desktop computer

where the main database is stored. • Daily analysis of the data can then be carried out to determine the breakdown of activities for each

supplier, package and task for that day. • The data can be presented in graphical formats and distributed to the site and project management

team who can assist with determining the causes of non-added value time. • The information can be presented at the daily site management team meeting enabling the

management team to address the previous day’s performance and making improvements in the forthcoming days. Based on the data collected and the feedback gained the improvement can be targeted at a number of levels including the supplier, the work package or the task. Therefore, a focused process of continuous improvement can be followed.

The information can also be used for planning resource levels for current and future projects and for comparison with other projects. The observer will also be able to take a series of photographs of progress on site that can used for compiling reports and for downloading on to a website for access by people not based on site.

Added Value Statutory

Non Added Value

Support

Activity Codes

SU Supervision

T1 Setting out

T2 Testing and checking

Not seen during observation round

Handling materials from stores to workplace

Not working and not at the workplace

Not working at the workplace

Making good or correcting

Walking around site

A

H1

I

N

RT

W

Carrying out the prescribed task

Preparation of materials

F

P Handling materials at the workplace

Unloading

H2

U

C Cleaning HS Carrying out work related to health and safety

related to safety

RO Inclement weather

BK Taking Break


Appendix B: SMARTAudit Waste Measurement

SMARTAudit is an integral part of the SMARTWaste (Site Methodology to Audit, Reduce and Target Waste) System that provides a web-based, integrated, practical approach to evaluating waste and its generation. It can be applied to any waste generating activity, and has already been adapted and used for the construction, demolition, refurbishment, manufacturing and pharmaceutical industries.

The system can identify cost savings, improve resource use, improve productivity and demonstrate continuous improvement through:

• waste benchmarking • identifying key waste products for reduction, reuse and recycling • sourcing local resource and waste management facilities

• sourcing local supplies of reclaimed and recycled building products.

SMARTAudit is a unique tool that audits in detail the source, type, amount, cause and cost of waste on site which is reported in any easy to understand format.

The SMARTAudit measurement process uses a similar technology to CaliBRE to input the data and feed into a database. Waste on sites is collected and placed in skips. The CaliBRE monitor can use the same hand-held computer (PDA) to record data on waste produced on site.

The contents of the skips are assessed and the volume of each waste product is recorded. The following details are logged:

• location of the skip on site • product wasted • volume of waste produced (m³) • cause of waste • work package creating the waste • product dimensions • any notes & photographs

The data is downloaded into a web-based database which presents the data in graphical and tabular formats for presentation. The tool also generates EPIs (m3 of waste per 100m2 of floor area) and KPIs (m3 of waste per £100K project value) for each site. For a development of 80 conventional houses, it is estimated that 3 hours a day will be needed to collect data on waste generated on site.

The data is assessed and recommendations can be made for improving the site waste management system. Information can be provided to the contractor on how the site waste management process can be improved including what materials can be reused and recycled as well as sourcing local waste recycling facilities. The SMARTWaste toolkit includes the BREMAP system, a geographical information system (GIS) that enables firms to reduce their transport of bulky waste by locating the nearest and most suitable waste management site.


79

Product type Examples of products on site

Ceramics Bricks, bathroom and kitchen wall tiles

Concrete Concrete and aircrete blocks, lintels, surplus readymix concrete

Inert Topsoil, spoil mix (soil and rubble)

Insulation Sheet material (polystyrene), ICF extruded polystyrene; steel frame insulation rolls (glass fibre)

Metals Pipes (copper pipes, steel pipe), wires/cables, ironmongery.

Timber Stud wall sections, decorative – skirting and architrave, fascia and soffit board, shuttering

Packaging Plastics (polythene sheet, empty bags, sealant tubes); timber (pallets, packaging)

Plaster/cement Plasterboard, finish plaster; cement (cement bags, mortar, render)

Product categories and examples of products on site


Appendix C: SmartLIFE and the measurement process overview

SmartLIFE is an innovative pilot project led by Cambridgeshire County Council which is dedicated to the delivery and promotion of Modern Methods of Construction (MMC) and sustainable growth. The main aims address the three challenges of housing delivery in growth, as experienced in the Cambridgeshire and Peterborough growth area: • affordability • sustainability/energy efficiency • skills/capacity shortages in the construction industry

This report deals with the construction project component of the SmartLIFE project, which aims to deliver a 106 unit affordable housing demonstration in association with the key stakeholders: English Partnerships, Warden Housing, Fenland District Council and the Building Research Establishment.

The affordable housing demonstration, discussed here, aims to construct 106 units on three sites in the Fenland District of Cambridgeshire using standard house types. One will consist of 56 units including 35 steel framed houses and 21 brick and block houses; one site will consist of 15 timber framed houses and one site with consist of 15 insulating concrete formwork houses and 20 brick and block houses. The construction of these houses will be monitored throughout the build process and comparative cost and performance measures will be made.

The measurement process

A key component of the SmartLIFE project is monitoring and evaluating the sites in terms of their construction performance as set out in the ‘Measuring Process’ document. In order to carryout this, a site measurement study is being carried out on all the SmartLIFE sites in collaboration with Willmott Dixon.

BRE is recording the tasks undertaken on the construction site, waste produced and as well as measuring water, energy usage and distance travelled for operatives to understand the environmental impact. By observation at selected times, it is possible to build up a picture of all of the activities which occupy the time taken to complete the project and the associated waste produced, cost and environmental impact.

Site observers employed by BRE and Inspace are based on site to collect and analyse the data. Their job is a full time job is to observe and record the activities on site. They are not measuring how long any operative takes and has no connection with the site organisation or with rates of pay or bonus systems. It is important to note that all data collected will be anonymous in that names of operatives are not just for data collection and reporting. The observer moves about the site throughout each day collecting data and taking photographs to record:

• Where work is being carried out on site – which blocks and plots

• What work is being carried out – work packages and tasks


81

• How efficiently time is being utilised – e.g. are there any delays, is work being repeated, how many visits to site are required by trades on site

• What waste is being produced on site, from which work package and why?

Most of the data is recorded electronically using a handheld computer. Once a day, the observer downloads the data from the computer into a PC In the site office, from which the analyst can make standard 'real-time' analyses of progress and performance.

Fundamental to the success of the project and the future development of process and design is why delays and wasted effort occur. To establish these the site observer is in regular contact with the site manager and subcontractors to establish cause and possible action to improve performance. Thus real knowledge lies with the operatives who raise issue with the management team that can related to design, methods of work, the supply chain or management.


Appendix D: Schedule of construction methods and house types for the project

Schedule of plots by construction method house type and tenure

Plot No House type & Tenure Plot No

House type & Tenure Plot No



House type & Tenure

1 R 1 SO 3 S 1 SO 26 S2 R 2 SO 4 S 2 SO 27 S3 S 8 S 5 S 3 SO 28 S4 S 9 S 6 S 4 S 29 S5 S 13 S 7 S 5 R 30 S6 R 14 S 10 R 6 R 31 S7 R 15 S 11 R 7 S 32 S8 R 16 S 12 R 8 S 33 S9 S 17 S 29 S 9 S 34 S

10 S 18 S 30 S 10 S 45 S11 S 19 S 31 S 11 R 46 SO12 S 20 S 32 S 12 R 47 SO13 S 21 S 33 R 13 R 48 S14 R 22 S 34 R 14 SO 49 S15 R 23 S 35 R 15 SO 50 S

24 S 16 SO 51 S25 S 17 R 52 S26 S 18 R 53 S27 S 19 SO 54 S28 S 20 SO 55 S

21 S 56 S22 S23 S24 S25 S35 R36 R37 R38 R39 R40 R41 R

R 42 SOS 43 SSO 44 S

Timber frame Polar Wall insulated concrete

Traditional Brick & Block

Sale

House type key

Light Weight Steel Frame

HEREWARD HALL NORWOOD ROAD

Traditional Brick & Block

BEAUFORT DRIVE

Shared Ownership

Rent

2 Bed 4 person

2 Bed 4 person

3 Bed 5 person

3 Bed 5 person

3 Bed 5 person

4 Bed 6 person

Tenure key

E3-01

A2-02

A2-01

B3-01

B4-01

B3-02

SmartLIFE SITE MEASUREMENT

Documents

Transcript of SmartLIFE SITE MEASUREMENT