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Life cycle of buildings, demolition and recycling potential:A case study in Turin, Italy

Gian Andrea Blengini a,b,Ã

a DITAG: Land, Environment and Geo-Engineering Department, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Turin, Italyb IGAG-CNR: Institute of Environmental Geology and Geo-Engineering, Corso Duca degli Abruzzi 24, 10129 Turin, Italy

a r t i c l e i n f o

 Article history:

Received 4 November 2007

Received in revised form

20 February 2008

Accepted 12 March 2008

Keywords:

LCA

Life cycle

Recycling

Demolition

Aggregates

Resource conservation

a b s t r a c t

One of the most challenging issues presently facing policymakers and public administrators in Italyconcerns what to do with waste materials from building dismantling activities and to understand

whether, and to what extent, the ever-increasing quantity of demolition waste can replace virgin

materials. The paper presents the results from a research programme that was focused on the life cycle

assessment (LCA) of a residential building, located in Turin, which was demolished in 2004 by

controlled blasting. A detailed LCA model was set-up, based on field measured data from an urban area

under demolition and re-design, paying attention to the end-of-life phase and supplying actual data on

demolition and rubble recycling. The results have demonstrated that, while building waste recycling is

economically feasible and profitable, it is also sustainable from the energetic and environmental point

of view. Compared to the environmental burdens associated with the materials embodied in the

building shell, the recycling potential is 29% and 18% in terms of life cycle energy and greenhouse

emissions, respectively. The recycling potential of the main building materials was made available in

order to address future demolition projects and supply basic knowledge in the design for dismantling 

field.

& 2008 Elsevier Ltd. All rights reserved.

1. Introduction

Although it is well known that the use phase firmly remains

the most important contributor to the life cycle impacts of 

buildings [1], interest in understanding energy use, the consump-

tion of natural resources and pollutant emissions in a life cycle

perspective is growing, as reported in a number of previous

studies [2–7]. In order to really appraise the overall environmental

impacts of buildings, all the life cycle stages should in fact be

encompassed by also including the embodied energy and

environmental interventions related to the construction materials,

construction activities, dismantling operations and the end-of-lifeof the materials.

According to the Rapporto energia e ambiente 2005 issued by

ENEA [8], the use phase of buildings in Italy roughly corresponds

to 31% of the final energy use and 31% of greenhouse emissions

throughout the country in the year 2004. However, when using

the life cycle approach, therefore including the manufacturing of 

construction materials (cement, bricks, glass, ceramics, etc.) and

considering building activities, the final energy use rises to 37%

and greenhouse emissions to 41%.

As the concern over environmental impacts of the construction

sector grows, more attention is being paid to those building

materials that prove to be more environmentally friendly, namely

materials that better meet the twofold objective of reducing both

consumption of non-renewable resources and general pollution

throughout their entire life cycle. In such a context, secondary

materials from demolition and building waste recycling deserve

interest.

One of the most challenging issues presently worrying policy-

makers and public administrators in Italy is to decide how to

dispose of waste materials from building dismantling activities,

whose quantities are becoming greater and greater: 40 milliontons per year according to APAT [9]. In such a context, the key

issue is to understand whether, and to what extent, such

demolition materials can replace virgin building materials and

save capacity of waste dumps, in a perspective of environmental

sustainability. As far as the environmental aspect is concerned, the

LCA methodology makes it possible to understand whether it is

worthwhile to replace virgin materials with recycled materials or

not [10].

Recycling strategies, in general, have in fact been criticised

because of their environmental impacts which sometimes exceed

the environmental benefits [11]. This is much more probable

when a product does not require a large amount of energy during

primary production e.g. recycled aggregates from rubble recycling.

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Contents lists available at ScienceDirect

journal homepage: www.elsevier.com/locate/buildenv

Building and Environment

0360-1323/$ - see front matter& 2008 Elsevier Ltd. All rights reserved.doi:10.1016/j.buildenv.2008.03.007

à Tel.: +3901156477 15; fax: +39 011564 7699.

E-mail address: blengini@polito.it

Building and Environment 44 (2009) 319–330

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In such a case, it is likely that more energy is being spent

throughout recycling than energy being saved as a consequence of 

avoided primary production.

Based on these preliminary considerations, the paper presents

the results of a research programme that was focused on the life

cycle assessment (LCA) of a residential building, located in Turin,

which was demolished in 2004 using the controlled blasting

technique, under the scientific supervision of the Politecnico diTorino. The research was part of a larger programme of urban re-

design run in co-operation between Turin municipality staff and

the Politecnico di Torino.

The overall objective of the research was to compare

alternative waste disposal scenarios, understand where resource

use and environmental impacts are concentrated and address

strategies for improvements.

A more specific objective was focused on the building waste

recycling process, in order to assess the recycling potential in

terms of energetic-environmental impacts and gains, based on

actual measured data from existing demolition and recycling

worksites. Recycling operations to convert rubble into secondary

aggregates and recycled reinforcing steel bars were carefully

analysed, the technical and economic feasibility, as well as theenvironmental sustainability of rubble recycling operations being

of great interest for the public administrators involved in the

programme.

With that in mind, a detailed LCA model was carried out in

compliance with Guinee’s definition [12] also in order to widen

the literature on LCA applications to the building sector, by

supplying field measured data on the demolition and rubble

recycling processes which are seldom addressed [2,7], in some

cases excluded [6] and often modelled using literature data

[1,13,14]. According to Scheuer et al. [15], there is limited

quantitative information on the actual process of demolition.

A further specific objective was to investigate the actual

recycling potential, as defined by Thormark [13,14,16], of different

building materials, compare the obtained results with literature

data and discuss the suitability and appropriateness of the

adopted solutions in order to address future demolition projects

and gather knowledge in the design for dismantling  field.

2. Methodology 

The Life Cycle Assessment (LCA) methodology has been used to

obtain a comprehensive energetic and environmental picture

relevant to the demolition and final disposal of a block of flats

located in Turin, Italy. Although the life cycle approach has not yet

been widely applied to the construction waste management sector

in Italy, in comparison with the industrial sector, there are some

examples of applications [17,18] and interesting future develop-

ment perspectives.According to ISO 14040 [19], an LCA comprises four major

stages: goal and scope definition, life cycle inventory, life cycle impact 

analysis and interpretation of the results.

The Goal and Scope Definition phase defines the overall

objectives, the boundaries of the system under study, the sources

of data and the functional unit to which the achieved results refer.

The Life Cycle Inventory (LCI) consists of a detailed compilation

of all the environmental inputs (material and energy) and outputs

(air, water and solid emissions) at each stage of the life cycle.

The Life Cycle Impact Assessment (LCIA) phase aims at

quantifying the relative importance of all environmental burdens

obtained in the LCI by analysing their influence on the selected

environmental effects.

According to ISO 14042 [20], the general framework of an LCIAmethod is composed of mandatory elements (classification and

characterisation) that convert LCI results into an indicator for each

impact category, and optional elements (normalisation and

weighting) that lead to a unique indicator across impact

categories using numerical factors based on value-choices.

As there is neither consensus on weighting [6,10,11,15,21],

nor on the best weighting method to adopt, as far as the present

study is concerned, the LCIA phase was initially focused on the

characterisation step and thus the following six indicators wereconsidered:

GER (Gross Energy Requirement) as an indicator relevant to the

total primary energy resource consumption (direct+indirect+

feedstock) according to Boustead and Hancock [22];

GWP100 (Global Warming Potential) as an indicator relevant to

the greenhouse effect according to IPCC [23];

ODP (Ozone Depletion Potential) as an indicator relevant to the

stratospheric ozone depletion phenomenon;

AP (Acidification Potential) as an indicator relevant to the acid

rain phenomenon; EP (Eutrophication Potential) as an indicator relevant to

surface water eutrophication;

POCP (Photochemical Ozone Creation Potential) as an indicatorof photo-smog creation.

Characterisation factors for GWP, ODP, AP, EP, POCP indicators

are reported in SEMC [24].

However, due to the fact that policymakers and public

administrators often express their need for practical tools that

might simplify the decision process [11], despite the risk of 

loosing transparency, the Eco-Indicator 99 method [25] was also

used.

The LCIA was therefore run at two levels: the first level

corresponding to the characterisation step, thus supplying results

with a low level of aggregation, but with a high grade of 

objectivity, and the second level showing results with a high

level of aggregation, thus supplying a more comprehensiveenvironmental picture of the systems under study.

According to the ISO 14040 standard, in the last step of an

LCA study, the results from the LCI and LCIA stages must be

interpreted in order to find hot spots and compare alternative

scenarios. As energy is critical for sustainability of buildings,

the interpretation step was mainly focused on life cycle energy

(GER), which corresponds to total energy, as defined in Sartori

and Hestnes [1]. Although global warming potential is closely

correlated to energy use, GWP100 has also been considered in

order to understand whether the decarbonation of raw materials

that occurs during clinker burning can influence the recycling

potential in a concrete-framed building. Moreover, in order to

extend the assessment to other environmental aspects and obtain

a more comprehensive, but synthetic, picture, Eco-Indicator 99

was also used. Eco-Indicator 99 is a weighting method that

converts inventory results into a single score comprehensive

environmental indicator that encompasses human health, ecosys-

tem quality and use of resources. The hierarchist version of Eco-

Indicator 99 and the H/A weighting set, based on a panel expert

approach, as fully reported in Goedkoop and Spriensma [25], were

used.

SimaPro 6 [26] and Boustead Model 5 [27] software applica-

tions were used as supporting tools in order to implement the LCA

model and carry out the assessment.

3. LCA application to demolition and rubble recycling 

The present LCA study deals with a residential block of flatslocated in Via Fratelli Garrone, Turin, Italy (see Fig. 1 and Table 1).

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The building was erected by Recchi SpA in 1965 and demolished at

the end of the year 2004 after 40 years of lifetime.

The study consisted of a from-cradle-to- grave LCA of a real case

residential building which included all the life cycle phases, with

emphasis on production of construction materials and end-of-life

management. Inventory data from previous LCA research relevant

to cement and concrete products [28,29] were used as input data

for the LCA modelling, thus increasing the local representative-ness of the achieved results. As far as end-of-life is concerned, a

great effort was made by the Politecnico di Torino research staff to

design and monitor the building demolishing by blasting and to

address rubble recycling.

The main objectives relevant to the present research include:

Analysing the relative contribution of life phases to the overall

energy consumption and environmental impacts of an existing

residential block of flats;

Analysing the relative contributions of building materials to

the pre-use phase impacts;

Identifying environmental impacts and benefits relevant to

demolition and rubble recycling;

Assessing opportunities for alternative end-of-life scenarios; Assessing the actual recycling potential of building materials in

a life cycle perspective.

 3.1. Functional unit 

According to Adalberth et al. [2], a frequently adopted

functional unit is the unitary internal-usable floor area, some-

times with reference to the whole building life span and

sometimes with reference to 1 year. However, in some cases, the

reference unit is chosen as a single flat, considered as a living unit,

or might even refer to the number of occupants living inside the

building.

Such a choice is, of course, arbitrary, but, for comparison

purposes, a standardisation might be helpful. This is also relevantto the function of the system under study: supplying a home for

residential use for a given period of time. All this considered, the

adopted functional unit in the present case-study is 1 m2 net floor

area, over a period of 1 year.

 3.2. System boundaries

Three distinct phases: pre-use, use and end-of-life were

included in the model (see Fig. 2). Data for the LCA model were

retrieved from different sources, as reported in Table 2. In

particular, inventory data for concrete and cement products were

retrieved from previous LCA research by the author [29], while

other building materials, ancillary materials and use of building

equipment were modelled from Idemat 2001 [30] and ETH-ESU

[31] databases included in the SimaPro software package. The

Buwal 250 database [32] was the source for transport operations,

electricity and diesel use. Inventory data for steel recycling from

steel scrap were made available by IISI (The International Iron and

Steel Institute) [33].

The pre-use phase consists of the manufacturing and transpor-tation of building materials, as well as the erection of the building

envelope. Therefore, in order to complete the model, inventory

data relevant to the most important building materials were

included. The quantities were estimated from original building

drawings. However, the materials embodied in the building

fixtures were the most difficult to estimate. While an estimation

of copper wires was attempted, no reliable estimations for water

pipes, heaters or other equipment were feasible, therefore such

elements were excluded. Sanitaryware items, whose position

and dimensions could be gathered from design drawings, were

included. Elements such as furniture, cooking equipment and

mobile items, were not included. As far as production and

transportation of concrete and cement are concerned, it was

assumed that such products were manufactured in existing plantsby local producers. Steel reinforcing bars were assumed to be

produced according to the average processes that characterise the

European steel industry [33]. Inventory data for such products

were gathered from IISI (International Iron and Steel Institute), as

well as from databases included in the SimaPro/Boustead software

packages. With regard to the shell construction, it is important

to recall that the block of flats under analysis was built by

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Fig. 1. View and location of the building under study.

 Table 1

Main features of the Via Garrone building

Building features

Basement shape Rectangular

Basement dimensions 56.7 mÂ11.7 m

Total elevation 36 m

Elevation, per floor 3 m

Basement depth À1.58m

No of floors above ground level 10

Total building volume 22,000 m3

No of flats 80

No of lifts, stairs 4

No of flats, per floor 8

Net area, Type A flat 65.8 m2

Net area, Type B flat 86.75 m2

Gross area, per floor 663 m2

Net area, per floor 611 m2

Total net area (usable) 6110 m2

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assembling prefabricated elements. This makes a considerable

difference, in comparison with a conventional on-site building

technique, in terms of energy and ancillary material use, as well as

in terms of material wasted during the construction of the

building. Therefore, operations for erecting the house were

considered in terms of energy use and construction waste factors.

The use phase encompasses all activities related to the use of 

the house, over the 40-year life span. These activities include all

operating energy consumed for heating, cooling, sanitary water

production, lighting and cooking. As a detailed survey on theactual operational phase of the building was not one of the overall

objectives of the research, basic information on energy use was

obtained from official statistics [8] and therefore represents the

average Italian situation. Moreover, it is worth noticing that, in

addition to the day-to-day residential use of the building, some

authors [2,4,5] also include energy and materials for refurbish-

ment in the use-phase. However, in this specific case study, due to

the fact that the research was mainly focused on the influence of 

material production and recycling, and due to the fact that

virtually all interior walls were made of reinforced concrete,

therefore not allowing significant building re-modelling, main-

tenance operations were included in the pre-use phase.

As the last step, the end-of -life phase inventories the demolish-

ing of the building shell and the final disposal of waste (see Fig. 3).Field measured data relevant to the dismantling operations were

included by encompassing the preliminary operations before

blasting, on-site primary treatment of the dismantling products

and transportation of the rubble to recycling or landfill facilities.

Two main groups of waste materials were sent for recycling: the

first made of lithoid based materials such as concrete, bricks,

mortar, plaster, glass, ceramics and the second constituted by steel

products. Doors and windows were partially disassembled and

removed before blasting, but their disposal was considered to fall

outside the system boundaries and was therefore not included in

the LCA model. Quantities of rubble after secondary demolitionand recycled material flows were measured on-site by weighting

the trucks and checking the transportation records. According to

these records, less than 1% of the rubble was landfilled (plastic,

insulating materials, etc.), while 99% was converted into recycled

materials. The lithoid fraction was converted into a secondary

aggregate and used as infilling material, therefore avoiding

the production of virgin aggregates and their transportation.

The steel material was partially recovered directly at the worksite

and partially separated from the lithoid fraction after rubble

beneficiation and sent to the steel factory to be recycled into

reinforcing steel bars, therefore avoiding the production of 

primary steel.

As rubble crushing and sorting allow both secondary aggregate

recycling and steel scrap magnetic separation, a simple massallocation criterion was adopted.

ARTICLE IN PRESS

Building materialproduction

Residual waste landfillBuilding waste recycling

 Transport

Building shellconstruction

Buildingdismantling/demolition

 Transport Transport

PRE-USE

PHASE

END-OF-LIFE

PHASE

Recycled steel bars(avoided product)

Recycled aggregate(avoided product)

Raw materialmining/quarrying

USE PHASE

(40 years)

Fig. 2. System boundaries.

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4. Inventory analysis

An LCA model of a complex system, such as a block of flats,

usually results in a network made of several process units.

A description of the main inventoried elements is given in the

following paragraphs.

4.1. The building and its construction phase

In order to systematically detect and quantify the building

shell components, 10 subsystems were identified, as shown in

Table 3.

Table 4 summarises the quantities of the main materials

embodied in the shell, the transportation distances and the

building waste factors, the latter being adapted from Blanchard

and Reppe [5] and Chen et al. [7]. The total estimated mass of the

building was 8882ton. The reinforced concrete was assumed to

be composed of 105 kg of reinforcing steel bars and 2395 kg of 

concrete per cubic metre. The main energetic and environmental

characteristics of the cement and concrete used in the LCA model[29] are summarised in Table 5.

Fig. 4 shows the relative contribution of the inventoried

building materials. Concrete is the main constituent, representing

83% in mass, followed by steel bars, bricks and plaster (4% each).

Mortar and ceramics (the latter including ceramic tiles, glass and

sanitaryware) contributed by 2% each. Other items: painting,

insulating materials, wood, copper, aluminium and plastics, all

together contributed less than 1%.

As far as building operations for the shell erection areconcerned, the energy use was estimated as 800 GJ of electricity

and 1480GJ of diesel for crane, building equipment, trucks,

diggers and loaders. An estimation of material losses during the

construction phase was carried out by analysing literature data [5]

and considering the peculiarities of the building technique

adopted for the building under study. Average transport distances

were considered, as reported in Table 4.

4.2. The building use phase

The building use phase was inventoried by considering

statistical data [8] according to which the yearly energy

consumption of an average Italian residential building is 16.5kgoil equivalent per square metre. Therefore, 168.88 TJ of end-use

energy, corresponding to the day-to-day running of the block of 

flats over the 40-year life span, were included in the model.

Heating (67%) was powered by diesel during the first 10 years and

then converted to natural gas for the remaining 30 years, while

the sanitary water supply (12%) and cooking (6%) were powered

by natural gas. Lighting (14%) was powered by electricity

according to the Italian mix.

4.3. The building demolishing and rubble disposal phase

The building under study was demolished using the blasting

technique, placing explosive charges on one side of the shell

basement. As can be seen in Fig. 3, the whole building shell was

made to topple on one side and subsequently the structure was

further demolished by means of hydraulic hammers and shears.

Before blasting, the whole area was rendered safe: the trees

were cut, the streetlights were removed, the walking area was

delimited and protection barriers were positioned against blast

throwing. Moreover, in order to support blast demolition, the

building shell was weakened by cutting some pillars, concrete

slabs, beans and walls using diamond wire and diamond disk

cutting machines. Blast holes (25–35 mm diameter) were drilled

and charged with explosive cartridges. Pre-blasting operations

were carried out over a period of 3 months and were included in

the LCA model, as shown in Table 6.

After blasting, a first on-site size reduction and material

selection was carried out using diesel–hydraulic equipment inorder to sort the rubble and send it to the appropriate disposal.

The on-site rubble treatment lasted 40 days.

Fig. 5 shows the sequence of rubble recycling activities, after

blast demolition, as they were included in the model (see Table 7).

The entire lithoid fraction was sent to the treatment plant

where about 8500 ton of recycled aggregates were produced. As

far as the LCA model is concerned, the production of recycled

aggregates was considered as an avoided impact equal to the

environmental burdens associated with the displaced natural

aggregates.

A mobile rubble crusher (see Fig. 3) Ulisse Omtrack II  equipped

with a jaw crusher and magnetic separator, which can operate a

size reduction from a maximum element size of 900mm to a

granulate 0–100 mm, was used in order to process the concrete,bricks, mortar, plaster, roof tiles, tiles, glass and sanitaryware.

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 Table 2

Building life cycle phases, subsystems and data sources

Lif e cycle p hase Sub sy stem Sou rces of d at a

Pre-use Bui lding materia l

production Inventory data for cement, concrete,

plaster and mortar from specific

measured data reported in Blengini

[29]

Inventory data for the other buildingmaterials from IDEMAT 2001 [30]

and ETH-ESU 96 [31]

Quantities estimated from building

drawings

Transport Average distances from specific

measured data

Data for transport operations from

Buwal 250 [32]

Building

construction

(including

refurbishment)

Energy use from personal

communications

Construction losses from literature

data reported in Blanchard and

Reppe [5]

Use (operational

phase)

Use of electricity

and fuels for

heating, sanitary

water, lighting

Average quantities from Italian

statistics [8]

Italian electricity mix from the

Buwal 250 database

Inventory data for fuel production

and use from Buwal 250

End-of-life Building demolition Demolition operations and

quantities from specific measured

data.

Production of explosives from the

ETH-ESU 96 database

Use of hydraulic equipment from

ETH-ESU 96 database

Aggregate recycling Specific measured data

Steel recycling Literature data reported in

Brimacombe and Shonfield [33] and

personal communications from IISI

(International Iron and Steel

Institute)

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As far as the steel waste is concerned, 225 ton (70%) were

immediately recovered at the worksite after demolition, while a

further 96ton (30%) was recovered after rubble crushing and

sorting. The avoided impacts corresponding to steel recyclingwere calculated according to the IISI procedure [33] which

supplies inventory data for steel production from both virgin

raw minerals (BOF—Basic Oxigen Furnace) and from steel scrap

(EAF—Electric Arc Furnace).

It is worth noticing that, while the lithoid rubble was

declassed to a relatively poor quality recycled material, steel

scrap can always be recycled into good quality steel bars with

roughly the same characteristics as virgin steel. According

to Brimacombe and Shonfield [33], the mass yield of secondary

steel production from scrap is 93.5%. The LCA model also

considered copper wire recycling from electric plants, including

wire separation from the insulating coating and the re-use of 

recovered wood after secondary demolition. The residual waste

(polystyrene, plastic, PVC, etc.) was modelled as the landfilling of inert waste.

5. Impact assessment and interpretation of the results

The impact assessment phase was carried out, by encompass-

ing both the characterisation and weighting steps, according to

the ISO 14042 standard. Table 8 summarises the achieved results

relevant to the life cycle of the building under study, with

reference to the adopted functional unit.

As the first objective of the research was an evaluation of the

relative weight of the life cycle phases, it clearly appears that, as

expected, the use phase of a conventional building overshadows

the rest of the life cycle, its contribution being variable from 90.1%

to 95.2%, depending on the indicator, thus confirming the results

obtained in previous studies [1]. The pre-use phase, considered as

the joint contribution of building materials and construction

operations, accounted for 6.2% to 11.5%.

It is worth noticing how the end-of-life corresponds to a

negative contribution or, in other terms, to a net achieved

environmental gain ranging from À0.2% to À2.6%. This can be

explained in terms of avoided impacts that can be traced back to

the secondary construction materials that enter future life cycles

in substitution of virgin products.

In this specific case study, the net environmental gain is given

by the difference between avoided impacts due to the substitutionof virgin building materials (gross credit) and impacts caused by

transportation and recycling processes (induced impacts). Thus,

the net environmental gain corresponds to the recycling potential

defined in Thormark [13,14]. Recycled materials will in fact be

used in future life cycles and the system from which they are

delivered must therefore be credited.

In accordance with the objectives outlined in the goal and

scope definition phase, the following interpretation steps were

carried out.

5.1. Contribution of construction materials

Fig. 6 shows the relative contribution of the building materialsto the impacts relevant to the pre-use phase. As can easily be seen,

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Fig. 3. Blast demolition and rubble recycling of the building under study.

 Table 3

Building envelope subsystems included in the model

Building envelope subsystems Main building materials

Basement Concrete, reinforcing steel bars

Structural walls Concrete, reinforcing steel bars, insulating

materials

Non-structural walls Bricks, mortar, paint

Floors Concrete, reinforcing steel bars, wire net,insulating materials

Floor surface lining Ceramics, linoleum, parquet, dimension stones

Do ors/wi ndows Woo d, g lass, plasti c, aluminium

Appliances (electric, sanitary

water, heating)

Pipes, ducts, sanitaryware, radiators

Roof Concrete, bricks, roof tiles, wood

St airs, elevators Concrete, r einf orcing s teel b ars

Wall surface lining Mortar, painting, ceramics, dimension stones

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the most important contributors are concrete and steel bars,

whose shares range from 29.4% to 71.4% and from 2.9% to

39.4%, respectively. While concrete is the first contributor

to global warming, ozone layer depletion, eutrophication and

photo-smog, steel is the main contributor to energy use andacidification.

5.2. Alternative end-of-life scenarios

In order to better understand the magnitude and therefore the

relative importance of a proper building end-of-life management,

a second disposal scenario was considered, Thus, after blasting

demolition and on-site size reduction, the rubble was considered

to be entirely landfilled. Fig. 7 shows the achieved results, the

comparison being restricted to the pre-use and end-of-life phases.

As can be seen, under the hypothesis that no rubble recycling is

carried out, no environmental net gains are achieved. Thus, the

recycling potential is lost and, consequently, the life cycle impacts,

excluding the building operational phase, are increased by 17%

to 54%.

5.3. Analysis of impacts and benefits relevant to demolition and

rubble recycling 

The results have shown that the end-of-life benefits are quitesmall in comparison with the whole life cycle, but their relative

importance increases when the comparison is restricted to the

pre-use phase.

For this purpose, the recycling processes were analysed more

in detail. The net and gross benefits or, in other terms, recycling

potentials and gross credits were compared.

Fig. 8 shows a comparison between the environmental burdens

of the materials embodied in the shell, the impacts relevant to

building waste recycling, the gross credits and the recycling

potential.

The analysis was focused on total energy use and greenhouse

emissions, as they are considered very important issues in the

building sector, but, in order to also encompass the other

environmental aspects, the analysis was also extended by usingEco-Indicator 99.

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 Table 4

Materials in the building envelope, inventory data sources, quantities, transport distances and construction waste factors

Material Data source Quantity (t) Transport distance (km) Construction waste factor (%)

Concrete Blengini [29] 7334 20 7

Steel bars IDEMAT 2001 [30] 321.4 150 7

Bricks IDEMAT 2001 [30] 385 20 10

Mortar Blengini [29] 188 20 10

Plaster Blengini [29] 363 20 10Paint ETH-ESU 96 [31] 9 20 7

Mineral wool ETH-ESU 96 [31] 16.1 20 7

Wood ETH-ESU 96 [31] 9.6 150 7

Glass ETH-ESU 96 [31] 9 30 7

Ceramic IDEMAT 2001 [30] 186.5 50 10

Roof tiles IDEMAT 2001 [30] 41 25 7

Plastic (PVC) IDEMAT 2001 [30] 21 50 7

Aluminium BUWAL 250 [32] 0.29 100 5

Copper IDEMAT 2001 [30] 0.5 100 5

 Table 5

Eco-profiles of the cement and concrete used in the LCA model

Impact category Indicator Unit Cement II A-LL 42,5 R (1 ton) Concrete Rck25 (1 ton)

Energy resources GER MJ 4756 642

Global warming GWP100 kg CO2(eq) 833 97

Ozone depletion ODP g CFC11eq 0.21 0.03

Acidification AP mol H+ 67.25 10.40

Eutrophication EP g O2(eq) 9760 1721

Photochemical smog POCP g C2H4(eq) 8.39 1.08

Source: Ref. [29].

AVERAGE MASS: 1.45 t/m2 (36 kg/m2, year)

others

1%

ceramics2%

plaster4%

bricks4%

mortar2%

concrete

83%

rebars4%

Fig. 4. Average composition of the building shell and fixtures.

 Table 6

Input data for the demolition operations

Operation Quantity

Electri city for di amo nd wi re/disk equipment (M J) 1080

Explosives (kg) 205

Detonating cord (kg) 20

Electricity for drilling (kWh) 175

Trench excavation (m3) 440

Damping heap creation (m3) 2000

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Reinforcing steel bars

 Transport toSteel factory 20 km

Steel recycling

(EAF)

Common waste:plastic, foam

board…

 Transport toLandfill 20 km

Wood

On site secondary demolition(separation, size reduction)

 Total rubble: 8,882 t

Hydraulic hammer use

37 t 225 t9.6 t

Recycled steel 96 tRecycled aggregate 8,514 t

Concrete, steel, bricks,roof tiles, ceramics,

mortar, plaster, glass

 Transport to

recycling facilities 10 km

Crusher 

Diesel useElectricity use

On sitere-use

Fig. 5. Activities for secondary demolition, waste processing and recycling.

 Table 7

Input data for the rubble processing operations

Operation Equipment Quantity (ton) Input data

Secondary on-site demolition Hydraulic hammer 2960 1330 m3

Mixed rubble loading Hydraulic loader 8882 4000 m3

Transport of steel to factory Truck 16 ton 321 6420 ton-km

Transport of steel to factory Train 321 35,310 ton-km

Transport of waste to landfill Truck 16 ton 25 502 ton-km

Transport of lithoid rubble Truck 28 ton 8622 86,220 ton-km

Lithoid rubble loading Hydraulic loader 8622 51,732 MJ

Crushing and steel separation (mobile equipment) Jaw crusher and magnetic separator 8622 11,588 kWh

Steel scrap loading Hydraulic loader 96 576 MJ

 Table 8

Results after the LCIA phase relevant to the Via Garrone building (data per m 2, year)

LCIA step Impact category Indicator Unit Material manufacturing

and transport

Envelope erection

and renovation

Use phase

(operation)

End-of-life

phase

Total life

cycle

Characterisation Energy resources GER MJ 69.7 (7% ) 21.1 ( 2.1% ) 928.1 (92.9% ) À20.3 (À 2.0% ) 998.6

Global warming GWP100 kg CO2 6.2 (9.2% ) 1.5 ( 2.3% ) 60.2 (90.1% ) À1.1 (À1.6% ) 66.8

Ozone depletion ODP mg CFC11 1.3 (4.2% ) 0.7 ( 2.4% ) 29.6 (94.4% ) À0.3 (À1.0% ) 31.3

Acidification AP mol H+ 1.1 (5.9% ) 0.4 ( 2.4% ) 17.3 (93.9% ) À0.4 (À 2.1% ) 18.4

Eutrophication EP g O2 144 (4.1% ) 71 ( 2.0% ) 3333 (95.2% ) À47 (À1.3% ) 3502

Photo-smog POCP mg C2H4 61.0 (6.5% ) 18.2 (1.9% ) 865.6 (91.8% ) À2.2 (À0.2% ) 942.7

Weighting – EI’99 Pt 0.34 (7.4% ) 0.10 ( 2.2% ) 4.27 (93.0% ) À0.12 (À 2.6% ) 4.59

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As a first step, some interesting remarks can be made

considering the ratio between recycling potentials and gross

credits given in Fig. 8, thus supplying an estimation of the

waste recycling efficiency. With such an approach, the recycling

efficiency, in terms of energy saving, can be estimated to be

around 54% and 83%, for recycled steel and recycled aggregates,

respectively. In other terms, if rubble and scrap are considered

to hold no environmental burdens, according to the so-called

‘‘ zero burden assumption’’ [34,35], the aggregates and steel

recycling processes have the potential of replacing virginmaterials, therefore avoiding their burdens (gross credit). Never-

theless, they are responsible for their own impacts (recycling

impacts), thus leading to the net gain (recycling potential). As far

as greenhouse emissions are considered, the saving efficiency

of steel recycling from steel waste is around 60%, while it is 82%

for aggregates. The magnitude of such figures is confirmed by

Eco-Indicator 99.

However, according to the objectives of the study, it would be

meaningful to compare the recycling potential with the environ-

mental burdens associated with the corresponding shell embo-

died materials. With this approach, it should be recognised that

the life cycle saving efficiency, expressed by the ratio between the

fourth and the first column of  Fig. 8, is significantly lower.

In the case of steel scrap, which can be re-converted into avaluable building material, similar to virgin steel, a net 50% life

cycle energy saving is achievable. On the contrary, in the case

of recycled aggregates, due to the fact that original building

materials (mainly concrete, mortar, plaster, bricks, etc.) were

downgraded into a relatively poor construction material (recycled

aggregate), the life cycle recovered energy is only 19%.

Therefore, while the process of aggregate recycling from rubble

is relatively less energetic expensive than steel recycling from

scrap, the life cycle benefits of steel recycling appear to be greater

than those achievable by recycling lithoid rubble.

When greenhouse emissions are considered, the life cyclesaving is 54% for steel and 10% for aggregates. If the analysis is

carried out using Eco-Indicator 99, the life cycle impact abate-

ments are 62% and 21% in the case of steel and aggregates,

respectively.

5.4. Sensitivity analysis

As mentioned in the goal and scope definition step, most of 

those inventory data considered strategic for the objectives of the

research were field measured data. Among these, primary

inventory data for concrete manufacturing and field measured

data relevant to the building end-of-life were used. However, in

order to assess the reliability and representativeness of theresults, a sensitivity analysis was carried out.

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0%

20%

40%

60%

80%

100%

Steel 39.4%

Concrete 29.4%

Mortar & plaster 8.1%

Brick & ceramics 12.4%

Others 10.6%

22.0% 2.9% 39.0% 29.0% 7.9% 35.7%

48.6% 71.4% 32.6% 42.6% 55.4% 31.2%

14.3% 19.8% 8.9% 11.8% 15.1% 8.7%

10.3% 1.0% 8.5% 10.1% 2.9% 15.9%

4.7% 4.9% 11.0% 6.4% 18.6% 8.5%

GER GWP ODP AP EP POCP EI-99

Fig. 6. Contribution of building materials to the impacts of the pre-use phase.

0%

20%

40%

60%

80%

100%

120%

140%

GER

160%

recycling scenario 100% landfillGWP ODP AP EP POCP EI-99

Fig. 7. Influence of alternative end-of-life scenarios on the life cycle impacts (use phase excluded).

G.A. Blengini / Building and Environment 44 (2009) 319–330 327

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7. Conclusions

The results gathered from the present LCA application to a real

building demolition in Italy have demonstrated that, in a life cycle

perspective, building waste recycling is feasible and profitable

from the energetic and environmental points of view. From an

economic point of view, it is worth noticing that all the recycling

operations were financed by private operators which saved costs

for not having to pay landfill taxes and obtained an income for

selling the recycled aggregates and steel scrap to downstream

private companies, without any public financial support.

A further important environmental benefit was achieved:

the avoided landfilling of demolition waste, therefore saving

capacity of waste dumps. This is a very important issue in terms

of sustainability as land is becoming more and more a scarce

resource, especially in a densely populated country like Italy, at

the same time industrialised and rich in natural and cultural

beauties. Further research should consider this issue within the

LCA analysis by using appropriate quantitative indicators.

Bearing this in mind, old buildings that have to be demolished

can be considered as aggregate quarries, but this must not be

misinterpreted. It is not fair to think that such new ‘‘secondary

quarries’’ could substantially displace conventional ones. Quality

requirements for commodities used in many construction activ-

ities do not allow the use of recycled material. Furthermore, decay

of quality, loss of mass, energy consumption and pollution caused

during recycling processes are objective and insurmountable

limits to recycling. The correct solution probably lies somewhere

between conventional and ‘‘secondary’’ quarries. It would be

unwise to underestimate one or the other.In order to achieve the best environmental solution and to

define the right proportion between the natural and recycled raw

materials that are necessary for the economic and social

development of mankind, all life cycle phases, from-cradle-to-

 grave, must be considered. Only with such an approach is it

possible to establish whether mankind is currently over-exploiting

natural raw materials and energy resources or, on the other hand,

is pursuing a dream of full recycling that causes secondary

materials to be more environmentally harmful than the corre-

sponding primary materials.

Moreover, if statistics relevant to yearly construction and

demolition waste production (0.7 ton per capita) are compared to

the yearly building aggregate requirement in Italy (6–11ton per

capita), it clearly emerges that the potential contribution of recycled aggregates to the Italian requirement ranges from 6% to

9%. Recycled and natural aggregates for the construction industry

should not therefore be considered in competition, but it is

strategic to consider their joint utilisation.

 Acknowledgements

The author would like to thank Tiziana di Carlo for her help in

the data collection and elaboration, Elena Garbarino of the

Provincia di Torino for her work on some of the estimations

relevant to building materials and Professor Vanni Badino for his

help in editing.

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