Hanham Hall Monitoring and Evaluation

Hanham Hall Monitoring and

Evaluation

Summary Report October 2015

Issue 1

Carried out for Barratt Homes Bristol Division

By Sarah Birchall

October 2015

19 October 2015

© BSRIA of 15 Report 57385/4

Hanham Hall Monitoring and Evaluation

Carried out for:

Barratt Homes Bristol Division Hanham Hall Whittucks Road Hanham BS15 3HY Contract: Report 57385/4 Date: October 2015 Issued by: BSRIA Limited

Old Bracknell Lane West, Bracknell, Berkshire RG12 7AH UK

Telephone: +44 (0)1344 465600 Fax: +44 (0)1344 465626 E: [email protected] W: www.bsria.co.uk

Compiled by:

Name: Dr Sarah Birchall

Title: Sustainability Engineer

Approved by:

Name: Saryu Vatal

Title: Senior Consultant

DISCLAIMER This report must not be reproduced except in full without the written approval of an executive director of BSRIA. It is only intended to be used within the context described in the text. This report has been prepared by BSRIA Limited, with reasonable skill, care and diligence in accordance with BSRIA’s Quality Assurance and within the scope of our Terms and Conditions of Business. This report is confidential to the client and we accept no responsibility of whatsoever nature to third parties to whom this report, or any part thereof, is made known. Any such party relies on the report at its own risk.

http://www.bsria.co.uk/

HANHAM HALL MONITORING AND EVALUATION EXECUTIVE SUMMARY

19 October 2015


EXECUTIVE SUMMARY

The development at Hanham Hall is the first significant type for Barratt Homes and represents a

further stage in their development of a specification for modern, energy efficient homes. Construction

at Hanham Hall started in 2012 and will continue until late 2015. The development consists of 185

dwellings in total, comprising a range of house types and a mix of private and social housing.

The dwellings, designed to comply with the zero carbon homes definition, incorporate a number of

features that are not commonplace in the UK house design including such as mechanical ventilation

with heat recovery (MVHR) systems, photovoltaics (PV) and solar shading systems. As part of the

HCA Carbon Challenge Brief, Barratt Homes contracted BSRIA to conduct a performance evaluation

at Hanham Hall to investigate whether the expected standard of energy efficiency is achieved by the

as-constructed and occupied buildings. The dwelling performance evaluation started in late 2013 and

will continue until 2019.

The overall objective of the evaluation work is to demonstrate if the as-built and occupied dwellings

achieve the predicted design performance. To achieve this a full evaluation of the process was

proposed, through basic investigations for all 185 dwellings and a more in-depth study of a sample of

up to ten. The evaluation work includes construction stage assessment, early occupation assessment,

occupant satisfaction surveys and face-to-face interviews, energy and environmental monitoring and

assessment and building fabric testing.

This interim report provides an overview of the evaluation and results to date. To ensure sensitivity of

data, the dwellings and plot numbers have been anonymised.

The results from the dwelling evaluation work undertaken by BSRIA at Hanham Hall thus far are

promising. There has been a lot of positive feedback from the residents at Hanham Hall and the energy

data is generally in line with the expected performance. Any issues highlighted by the residents are

being fed back to Barratt Homes for future design and projects and in addressing improvements on

site.

The building fabric testing will be carried out in the sample dwellings late 2015, when weather

conditions are more suitable for this type of investigation work.

BSRIA will continue with monitoring the dwellings within the development until 2018, with final

reporting in 2019.

HANHAM HALL MONITORING AND EVALUATION CONTENTS

19 October 2015


CONTENTS

EXECUTIVE SUMMARY ......................................................................................................................... 4

1 INTRODUCTION ........................................................................................................................... 6

2 SCOPE OF THE EVALUATION WORK ....................................................................................... 6

3 CONSTRUCTION STAGE ASSESSMENT AND AUDIT .............................................................. 7

4 HANDOVER REVIEW ................................................................................................................... 8

4.1 HOME USER TOURS ........................................................................................................ 8 4.2 REVIEW OF HANDOVER INFORMATION ........................................................................ 8

5 OCCUPANT FEEDBACK.............................................................................................................. 8

5.1 Occupant Survey ................................................................................................................ 8 5.2 Occupant interviews .........................................................................................................12 5.3 Recommendations to project team ...................................................................................12

6 ENERGY – HEADLINE PERFORMANCE TO DATE ................................................................. 12

6.1 Gas consumption ..............................................................................................................13 6.2 Electricity consumption .....................................................................................................14 6.3 Water consumption ...........................................................................................................14

7 EARLY IMPRESSIONS AND FUTURE WORK .......................................................................... 15

TABLES

Table 1 Handover questions and responses ......................................................................................... 10 Table 2 Rating of utility bills ................................................................................................................... 11

FIGURES

Figure 1 Terrace at Hanham Hall ......................................................................................................... 6 Figure 2 Overall dwelling satisfaction and comfort - average, maximum and minimum ratings .......... 9 Figure 3 Rating per property – Controls for heating systems ............................................................... 9 Figure 4 Rating per property – Controls for ventilation systems ........................................................ 10 Figure 5 Rating per property – Handover process ............................................................................. 10 Figure 6 Distribution of responses – rating heating utility bills ............................................................. 11 Figure 7 Distribution of responses – rating electricity utility bills ....................................................... 11 Figure 8 Distribution of responses – rating water utility bills.............................................................. 11 Figure 9 Actual vs. predicted annual gas consumption kWh/m

2/year ................................................ 13

Figure 10 Actual vs predicted annual electricity consumption kWh/m2/year ......................................... 14

Figure 11 Measured water consumption litres/day ............................................................................... 15

HANHAM HALL MONITORING AND EVALUATION OCCUPANT FEEDBACK

19 October 2015


1 INTRODUCTION

The development at Hanham Hall, designed to comply with the zero carbon homes definition, is the

first significant type for Barratt Homes and represents a further stage in their development of a

specification for modern, energy efficient homes. Construction at Hanham Hall started in 2012 and

will continue until late 2015. The development, set over twelve acres, consists of 185 dwellings in

total, comprising a range of house types, from one bed apartments to large five bedroom houses. The

grade two listed building Hanham Hall has been refurbished to include community functions. The

development includes a mix of private and social housing.

Figure 1 Terrace at Hanham Hall

The dwellings incorporate a number of features that are not commonplace in the UK house design

including such as MVHR systems, photovoltaics (PV) and solar shading systems. As part of the HCA

Carbon Challenge Brief, Barratt Homes contracted BSRIA to conduct a performance evaluation at

Hanham Hall to investigate whether the expected standard of energy efficiency is achieved by the as-

constructed and occupied buildings. The dwelling performance evaluation started in late 2013 and will

continue until 2019.

The overall objective of the evaluation work is to demonstrate if the as-built and occupied dwellings

achieve the predicted design performance. To achieve this a full evaluation of the process was

proposed, through basic investigations for all 185 dwellings and a more in-depth study of a sample of

up to ten. This interim report provides an overview of the evaluation and results to date. To ensure

sensitivity of data, the dwellings and plot numbers have been anonymised.

2 SCOPE OF THE EVALUATION WORK

The scope of the evaluation work BSRIA is undertaking includes:

1. Construction stage assessment and as-built audits

2. Early occupation assessment – review of handover and information provided to the home

owners/tenants

3. Occupant satisfaction surveys

4. Face-to-face interviews

5. Energy assessment and environmental monitoring data

o Basic monitoring in all 185 properties, which includes collecting gas (if applicable),

electricity and water monitoring data at 5 minute intervals

o In-depth monitoring in up to 10 sample properties (7 installations to date), which

includes, in addition to the above monitoring, sub-metering of electricity use for the

following circuits:

Power sockets

Lighting


19 October 2015


MVHR

Boiler heating circuit

Domestic hot water

Solar PV system generated and exported electricity

o Indoor air quality measurements in the sample dwellings, including:

indoor air temperature and relative humidity in two locations (main living

space and a bedroom)

carbon dioxide (CO2) level measurements in the living rooms.

o Additionally, in the sample of ten, the status of high level window opening and solar

shutter opening and closing will also be monitored using contact sensors.

6. Building fabric testing in sample dwellings – thermal imaging, in-situ heat flux measurements

and fan pressurisation testing.

3 CONSTRUCTION STAGE ASSESSMENT AND AUDIT

During the construction phase, inspections of a variety of house types at various construction stages

were carried out to verify that the key elements are consistent with the design drawings and

specifications in order to demonstrate that the as-built dwellings can achieve the predicted design

performance. The observations for the various build stages are summarised below.

Stage 1: Foundations & ground floor slabs (Type F), junction details

Work in progress appeared to be systematic and thorough, with careful attention to insulation slab

joints, DPC continuity to external wall and bitumen seal to party wall sections. It was noted to check

that floor U-value calculations account for the insulation thickness over the beam (cold bridging) in

this block & beam suspended floor design. Seven plots were inspected.

Stages 2: Internal floor structures, internal walls, junction details

Work in progress appeared to be systematic and thorough, with careful attention to all relevant

structural junctions between internal and external elements. Eight plots were inspected.

Stage 3: External walls (SIPs panels), internal walls, window & door openings, cavity insulation, and

junction details

With external walls made up from SIPs it was clear that care has been taken to avoid unnecessary

notching and drilling that might impact the structural strength. Junctions to internal and party walls

and intermediate floors appear to be effectively catered for. Four plots were inspected.

Stages 3 & 4: External & internal walls, window & door fitting, roof truss structure, structure

dimensions, fire barriers and junction details

Improvements to details applied to continuity of the air barrier at window and door openings were

demonstrated. Spot checks of setting out measurements showed no noticeable variation from the

plans. Four plots were inspected.

Stage 5: Provision for all internal services, wiring, piping and ducting, with attention to sealing details

The attention to systematic installation of services, with relevant insulation and bracing was evident,

although one or two minor omissions of sealing penetrations were seen, but it is assumed these would

be identified in the quality control process before finishing and closing service voids in walls and

floors. Seven plots were inspected

Stages 5 & 6: Internal fixing and finishing- internal and party wall insulation and sound proofing,

internal roof finishes and junction details

The clean and tidy work practice seen throughout the construction process was again evident in all the

procedures in progress. The positioning of the MVHR inlet and exhaust vents on the Type F design


19 October 2015


was noted as a matter for concern, where these are facing at each other at 90o within a sheltered space,

providing the possibility of pollution to the air intake. It was later noted on some finished units, that

the distance between MVHR vents was not always consistent. Four plots were inspected.

Stage 8 Final finishes and painting, access to controls and metering

All fit out was seen to be as specified, with suitable access to all controls. Four plots were inspected.

Stage 9: Ready for handover. Final finishes, M&E fit out, PV panels, solar shading, access to controls

and metering

All fit out appeared to be as specified, with suitable access to all controls. Nine plots were inspected.

Construction stage assessment conclusion

The overall on site management, communication and quality control is clearly being systematically

applied to ensure good insulation continuity and enabling an effective air barrier to be established,

demonstrating that the high standard specified can be achieved.

4 HANDOVER REVIEW

4.1 HOME USER TOURS

4.1.1 Overview of tours to date

Thus far, BSRIA have observed a number of new home tours conducted by Barratt Homes for the

private owners. The Housing Association operate their own handover process for their residents and

BSRIA plans to observe these in the coming months once dates have been provided. Once all

handovers are completed, BSRIA will finalise this stage of the evaluation.

4.2 REVIEW OF HANDOVER INFORMATION

BSRIA are currently in the process of reviewing the handover pack and other information provided to

the occupants at handover. Once all handovers are completed, BSRIA will finalise this stage of the

evaluation and report on the findings.

5 OCCUPANT FEEDBACK

5.1 OCCUPANT SURVEY

5.1.1 Introduction and background information

The occupant feedback survey has two aims:

1. To obtain basic household information – including number of people, typical occupancy

patterns, ownership status, for example.

2. To gain occupant feedback regarding their perceived comfort and satisfaction with the

dwelling, including the handover process, operation and running costs.

The survey form also includes questions with tick-box responses and spaces for any additional

comments to be made by the respondents.

Hanham Hall residents were sent the feedback forms and a stamped addressed return envelope by post

in May 2014 and January 2015. The residents were asked to complete this and return it by post.

As of June 2015, BRSIA has received 61 responses to the survey form sent to 136 of the residents.

The basic household information is essential for all dwellings. The average number of people per


19 October 2015


house is 2.2; 1.8 adults and 0.5 children. Ideally these forms are to be completed by those who have

been residents at Hanham Hall for at least one year. The next batch of surveys will be sent late 2015.

5.1.2 Overall satisfaction and comfort

The questions relating to the satisfaction and comfort with the home were all based on a 5-box scale (1

to 5, where ‘1’ would be not satisfied and ‘5’ would be very satisfied). The minimum, maximum and

average ratings for the responses received to date are shown in Figure 2.

Figure 2 Overall dwelling satisfaction and comfort - average, maximum and minimum ratings

The average scores relating to satisfaction and comfort were greater than 4, out of a possible 5, for all

variables except for the control- related ones. This was also reflected in the comments received. The

controls for heating had a lower (worse) score than that for ventilation. The distribution of the ratings

for the comfort variables per property are presented in Figure 3 and Figure 4. The blue bars in these

figures indicate the owner-occupied plots, red bars are plots owned by the Housing Association and

the orange bars are for ‘other’ (both shared ownership).

Figure 3 Rating per property – Controls for heating systems

Responses from nine different plots evaluated their experience with the heating control at the lowest

score (at 1 out of the possible 5).

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Average Maximum Minimum

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1

2

3

4

5

Rat

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Property

How is your experience with controls for the heating systems?


19 October 2015


Figure 4 Rating per property – Controls for ventilation systems

The occupants in five of the plots evaluated their experience with the ventilation control at the lowest

score (at 1 out of the possible 5).

5.1.3 Occupant’s view of the Handover experience

The form included questions relating to the handover process, as shown in Table 1. All responses

indicated that a handover was provided. The survey asked the respondents to rate the handover

process. The average rating for this was 4.1 (out of a possible 5). The distribution of scores is shown in

Figure 5. Handover scored a lower average than most of the other variables (except control), however

still an acceptable score. Five out of the six responses from homes that are rented through the housing

association had ratings of 3 out of 5 (see Figure 5).

Table 1 Handover questions and responses

Question: Number of

responses

Yes No Don’t

know

Were you given a Home User Guide when you

moved into your home

57 52 1 4

Have you used the Home User Guide since

moving into your home

55 42 8 5

Figure 5 Rating per property – Handover process

5.1.4 Running costs

The form included questions about how utility bills at Hanham Hall compare with the occupant’s

previous residence.

The feedback to date indicates that, for most residents, the utility bills, particularly for heating and

electricity, have reduced since moving to Hanham Hall. The average, maximum and minimum scores

0

1

2

3

4

5

Rat

ing

Property

How is your experience with controls for the ventilation systems?

0

1

2

3

4

5

Rat

ing

Property

How would you rate the handover process when you moved into your home?


19 October 2015


for these are shown in Table 2. The distributions of the responses are shown in Figure 6, Figure 7 and

Figure 8. However, this is relative to their previous accommodation and does not necessarily represent

how the homes are performing compared with the intended energy efficiency.

Table 2 Rating of utility bills

Statistic Heating utility bills Electricity utility bills Water utility bills

Number of responses 60 60 59

Average 1.7 1.7 2.1

Maximum 4 4 5

Minimum 1 1 1

Figure 6 Distribution of responses – rating heating utility bills

Figure 7 Distribution of responses – rating electricity utility bills

Figure 8 Distribution of responses – rating water utility bills

05

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1 2 3 4 5 Don'tknow

Nu

mb

er

of

resp

on

ses

Rating

Compared with your previous residence, how do your heating utility bills compare at Hanham Hall?

0

5

10

15

20

25

1 2 3 4 5 Don'tknow

Nu

mb

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of

resp

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ses

Rating

Compared with your previous residence, how do your electricity utility bills compare at Hanham Hall?

0

5

10

15

20

1 2 3 4 5 Don'tknowN

um

be

r o

f re

spo

nse

s

Rating

Compared with your previous residence, how do your water utility bills compare at Hanham Hall?


19 October 2015


5.1.5 Summary and conclusions from occupant survey

For most aspects, the residents appear very satisfied with their homes and the way they perform.

Feedback related to their experience over controls of the heating and ventilation systems indicates

lower levels of satisfaction.

Overall, there was positive feedback on the handover process given to the residents. Based on a scale

of 1 to 5, the handover process was rated 4.1 (where 1 is not good and 5 is very good), however this is

a lower score when compared with the other variables with the exception of control. The residents also

reported that compared to their previous residence, the utility bills are much lower at Hanham Hall.

The survey form included boxes for residents to provide any additional comments. The comments

received were mostly concerning the heating and ventilation system and controls and location of the

heating control panel. The bin stores were mentioned in some of the comments and their concerns over

the noise and smells from these areas were raised.

5.2 OCCUPANT INTERVIEWS

Thus far five interviews with the residents have taken place - four were private owners and one rented

through the Housing Association. The interviews were all conducted in a semi-structured manner. The

interviews generally included discussion about general household information including the number of

people, occupancy times, the handover process, the operational aspects including controls and ease of

use. There was opportunity for any additional comments about the dwelling or the development.

The feedback from the interviews conducted to date has revealed occupants concerns with use of

heating controls and the handover process and information provided. One of the residents also reports

they switch the MVHR system off at night because of the noise it causes. It is important the systems

operate as intended because inadequate ventilation can have implications on health and well-being of

the occupants.

BSRIA will continue to conduct interviews throughout the project and report in further detail in due

course.

5.3 RECOMMENDATIONS TO PROJECT TEAM

BSRIA would advise Barratt Homes review the feedback highlighted and address issues where

possible. It would be beneficial if Barratt Homes engaged with the occupants, particularly those who

have expressed dissatisfaction with the MVHR system/controls and heating system controls, and offer

training/support regarding the use of these controls and review user guides and control interface. A

training workshop open to all residents could provide an opportunity to explain how to make best use

of the systems and controls within the properties at Hanham Hall.

6 ENERGY – HEADLINE PERFORMANCE TO DATE

The houses at Hanham Hall were designed to comply with the zero carbon homes definition and to

generally achieve a reduction of 40% or more in the CO2 emissions emitted due to regulated energy

use. The houses were evaluated using SAP 2009, which gave an assessment of monthly space heating

and cooling loads and includes a procedure to calculate unregulated energy use for cooking and

appliances. While it is noted that the predicted energy demand is based on standardised assumptions

for the number of occupants and occupancy patterns, the comparison of actual energy use and the

predicted demand will help understand how representative the calculations are.


19 October 2015


The analysis BSRIA is undertaking aims to help the project team understand the energy demand

profiles of these homes and use the learnings to inform future developments. It will also look at

whether the sensitivity of the house types (attached, semi-detached, mid-terraces and flats) in the

energy prediction tools is reflected in the monitored energy use data as well.

In the charts below the detached homes are represented by blue bars, the semi-detached/end-terraces

by orange bars and the mid-terraces by green bars. Flat types are also highlighted on the charts –

ground-floor flats are represented by grey bars, mid-floor flats by purple and top-floor flats by pink

bars.

6.1 GAS CONSUMPTION

Most of the dwellings at Hanham Hall are heated by gas fuel (individual condensing gas boilers). Flats

are electrically heated. Figure 9 shows the total annual gas consumption, normalised to kWh/m2, in 52

properties where data covering the whole of 2014 was available. Weather corrections have not been

applied to the measured data. Figure 9 includes the predicted consumption, as determined by SAP.

This includes fuel for both space heating, which is designed to be low with the well-insulated and

well-built external fabric, and the domestic hot water demand.

The average gas use at Hanham Hall in 2014 was approximately 58kWh/m2/year, which significantly

less than the typical heating energy benchmark of 110kWh/m2/year for a house built between 1965 and

19901. However, the consumption across the development did vary in 2014, ranging between

10kWh/m2/year and 140kWh/m

2/year.

Out of the 52 properties, compared with the predicted consumption, the measured gas consumption

was:

similar or less in 13 properties

up 25% more in 11 properties

between 25% and 50% more in 15 properties

between 51% and 100% more in seven properties

more than 100% in four properties

unknown in two properties due to missing SAP reports.

Figure 9 Actual vs. predicted annual gas consumption kWh/m2/year

1 http://www.buildingsdata.eu/data-search/results

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(kW

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Property

Annual gas consumption kWh/m2

Actual gas consumption 2014 kWh/m2 Predicted annual gas consumption kWh/m2

http://www.buildingsdata.eu/data-search/results


19 October 2015


6.2 ELECTRICITY CONSUMPTION

Excluding the show-homes, 65 of the properties have electricity data recorded for 2014. These annual

measured and predicted consumptions, both normalised for internal floor area are shown in Figure 10.

With some exceptions, the data indicates that the measured electricity consumption is less than the

predicted total. The flat units, which use electricity for heating, appear to exceed the predicted

regulated electricity use, but are generally less than the total predicted.

The average electricity consumption measured in 2014 was 33kWh/m2/year, but the data does show

large variation in the electricity use - for house units it ranges from 9kWh/m2/year to 60kWh/m

2/year

and approximately 20 kWh/m2/year to 80kWh/m

2/year for flats. The mid-floor flats appear to have the

highest measured electric energy intensity.

Figure 10 Actual vs predicted annual electricity consumption kWh/m2/year

6.3 WATER CONSUMPTION

The installation of water efficient fittings in the dwellings at Hanham Hall aims to reduce water

consumption. BSRIA measured water consumption in 72 dwellings in 2014. At this stage in the

project, the data has been normalised in terms of litres per day and is presented in Figure 11. Water

consumption is dependent on the number, preferences and lifestyle of the occupants. The measured

water consumption varies significantly, with an average consumption of 163litres/dwelling/day.

The standards in Part G (Sanitation, Hot Water Safety and Water Efficiency) and the Code for

Sustainable Homes are expressed in terms of number of occupants. The homes at Hanham Hall were

designed to meet to maximum daily water consumption per person of 105litres/person. Once

occupancy data for all homes is available, then BSRIA will analyse the data in these terms.

0

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Property

Annual electricity consumption kWh/m2

Actual electricity consumption 2014 (kWh/m2)

Total predicted annual electricity consumption (regulated + unregulated) (kWh/m2/year)

Predicted annual regulated electricity consumption (kWh/m2/year)


19 October 2015


Figure 11 Measured water consumption litres/day

7 EARLY IMPRESSIONS AND FUTURE WORK

The results from the dwelling evaluation work undertaken by BSRIA at Hanham Hall thus far are

promising. There has been a lot of positive feedback from the residents at Hanham Hall and the energy

data is generally in line with the expected performance. Those issues and concerns highlighted by the

residents are all relevant and are being fed back to Barratt Homes for future design and projects and in

addressing improvements on site.

The building fabric testing will be carried out in the sample dwellings towards the end of 2015, when

weather conditions are more suitable for this type of investigation work.

A detailed interim report will be produced approximately 6 months after the last house is completed

(current estimated completion date is October 2015). BSRIA will continue with monitoring the

dwellings within the development until 2018, with final reporting due in 2019.

0

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500

Wat

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Property

Water consumtpion (litres/day)

Hanham Hall Monitoring and Evaluation

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