embodied carbon in construction in wm

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1. Introduction .................................................................................................... 1

1.1 Climate Change: the most prominent environmental issue .............................. 1

1.2 Impact of building material and construction on climate change in the UK ...... 3

1.3 The Climate Policies: Integrated Assessment Framework ............................... 3

1.4 The Embodied Carbon in Construction ............................................................ 4

1.5 Targets for carbon reductions .......................................................................... 7 1.5.1 European Directive in carbon reduction .......................................................................................... 7 1.5.2 UK target reduction ......................................................................................................................... 8 1.5.3 Birmingham City Council targets ..................................................................................................... 9

2. Project Aims and Methodology ................................................................... 11

2.1 Project Collaborators (WMCCE & BCP) ........................................................ 11

2.2 Project Aims................................................................................................... 12

2.3 Methodology .................................................................................................. 13

3. Measuring the Embodied Carbon ............................................................... 15

3.1 Survey of available tools ................................................................................ 15 3.1.1 Environment Agency programme ................................................................................................. 15 3.1.2 ECCM tool (Europe's leading centre of expertise in carbon management) ................................... 16 3.1.3 Wrap tool (The Waste & Resources Action Programme) .............................................................. 17

3.2 Selecting the most appropriate tool ............................................................... 19

3.3 Embodied Carbon Information and Sources .................................................. 20

4. Estimating the carbon footprint in three case studies .............................. 22

4.1 GF Tomlinson case study .............................................................................. 22 4.1.1 GF Tomlinson Group: Company profile ......................................................................................... 22 4.1.2 Colebourne primary school case study: construction site description .......................................... 23 4.1.3 Research: data input - output, impact, results and consideration ................................................. 25 4.1.3.1 Data Input - Output ....................................................................................................................... 25 4.1.3.2 Results and Considerations ............................................................................................................ 26

4.2 Thomas Vale case study ............................................................................... 30 4.2.1 Thomas Vale Group: Company profile........................................................................................... 30 4.2.2 Sutton New Road Offices, Erdington: construction site description .............................................. 31 4.2.3 Research: data input - output, impact, results and consideration ................................................. 32 4.2.3.1 Data Input - Output ....................................................................................................................... 32 4.2.3.2 Results and Considerations ............................................................................................................ 33

4.3 Wates case study .......................................................................................... 36 4.3.1 Wates Group: Company profile ..................................................................................................... 36 4.3.2 Case study description .................................................................................................................. 37 4.3.3 Research: data input - output, impact, results and consideration ................................................. 39 4.3.3.1 Data input - output ........................................................................................................................ 39 4.3.3.2 Results and Considerations ............................................................................................................ 40


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4.4 Evaluation of Results ..................................................................................... 41 4.4.1 Problems and difficulties in tool used and the data collection ...................................................... 41 4.4.2 Review of methodologies used ..................................................................................................... 42 4.4.3 Result Consideration and recommendations ................................................................................ 44

5. Conclusion .................................................................................................... 46

5.1 Reducing problems and Improving on advantages ........................................ 46

5.2 Recommended further research: Data base and Software development ...... 47

6. References .................................................................................................... 51


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1. Introduction

1.1 Climate Change: the most prominent environmental issueClimate refers to the average weather experienced in a region over a long

period, typically at least 30 years (12) . This includes temperature, wind and rainfall

patterns. The climate of the Earth is not static, and has changed many times in the

past in response to a variety of natural causes. The United Nations define the term

climate change with reference only to changes in climate which can be attributed to

human activity (UNFCCC).

Recent observed changes in global climate are likely to be due to a combination ofboth natural and human causes. The Earth's climate varies naturally as a result of

interactions between the ocean and the atmosphere, changes in the Earth's orbit,

fluctuations in energy received from the sun and volcanic eruptions. The main

human influence on global climate is likely to be emissions of greenhouse gases

such as carbon dioxide (CO 2) and methane. At present, about 6.5 billion tonnes of

CO 2 is emitted globally each year, mostly through burning of fossil fuel for energy.

The Earth is kept warm by the greenhouse effect. Certain gases in the atmosphere(so-called greenhouse gases) absorb energy that is radiated from the Earths

surface, and so warm the atmosphere. The greenhouse effect is a natural

phenomenon without which life on Earth as we know it would not be possible, as the

Earth could be around 30C cooler. However, our modern lifestyles have resulted in

us releasing large amounts of greenhouse gases like carbon dioxide and methane

into the atmosphere, enhancing the greenhouse effect and so pushing up

temperatures globally(2)

.Human activities generate several different greenhouse gases that contribute to

climatic change. On earth, the most abundant greenhouse gases are, in order of

relative abundance: water, vapour, carbon dioxide, methane, nitrous oxide, ozone

CFCs. Analyzing the combination of the strength of the greenhouse effect of the gas

and its abundance shows that the most important greenhouse gases are: water

vapour (which causes about 36-70% of the greenhouse effect on Earth), carbon

dioxide (which causes 9-26%), methane (which causes 4-9%) and ozone (which

causes 3-7%).
http://en.wikipedia.org/wiki/Water_vaporhttp://en.wikipedia.org/wiki/Carbon_dioxidehttp://en.wikipedia.org/wiki/Methanehttp://en.wikipedia.org/wiki/Nitrous_oxidehttp://en.wikipedia.org/wiki/Ozonehttp://en.wikipedia.org/wiki/Chlorofluorocarbon#Chloro_fluoro_compounds_.28CFC.2C_HCFC.29http://en.wikipedia.org/wiki/Water_vaporhttp://en.wikipedia.org/wiki/Water_vaporhttp://en.wikipedia.org/wiki/Carbon_dioxidehttp://en.wikipedia.org/wiki/Carbon_dioxidehttp://en.wikipedia.org/wiki/Methanehttp://en.wikipedia.org/wiki/Ozonehttp://en.wikipedia.org/wiki/Ozonehttp://en.wikipedia.org/wiki/Methanehttp://en.wikipedia.org/wiki/Carbon_dioxidehttp://en.wikipedia.org/wiki/Carbon_dioxidehttp://en.wikipedia.org/wiki/Water_vaporhttp://en.wikipedia.org/wiki/Water_vaporhttp://en.wikipedia.org/wiki/Chlorofluorocarbon#Chloro_fluoro_compounds_.28CFC.2C_HCFC.29http://en.wikipedia.org/wiki/Ozonehttp://en.wikipedia.org/wiki/Nitrous_oxidehttp://en.wikipedia.org/wiki/Methanehttp://en.wikipedia.org/wiki/Carbon_dioxidehttp://en.wikipedia.org/wiki/Water_vapor


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The currently observed impacts of climate change represent the reaction of the

climate system to the green-house gas emissions of the past two centuries as shown

in figure 1. Because of the inertia of the climate system, the impacts will not become

noticeable until the coming decades and consequently the climate of the Earth will

presumably continue to heat up for many centuries to come (1).

Figure 1: Global average Temperature (UK Climate Impacts, 5 November 2008) (2)

When referring to the post-industrial era, scientists generally use the term climate

change in the way defined by The United Nations Framework Convention on Climate

Change (UNFCCC).

The world is responding to this threat by taking global action to limit the emission of

GHGs into the atmosphere. In 1997, the UNFCCC adopted the Kyoto Protocol,

establishing legally binding targets for the developed countries that ratified the

protocol. It aims to reduce greenhouse gas emissions by an overall 5% below 1990

levels during the period between 2008 and 2012 (4).


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1.2 Impact of building material and construction on climate

change in the UK

Buildings generally are responsible for over a quarter of environmental

impacts in terms of: 30 % of the raw materials used, 42 % of the energy, 25% of

water used, 12% of land use, 40% of atmospheric emissions, 20% of water effluents,

25% of solid waste and 13% of other releases.

If we look at the broader construction including bridges, roads and so forth, materials

account for upwards of 70% of our total materials flow globally. Much of our total

construction activity is associated with residential development.

Materials used in house construction impact on almost every aspect of sustainability

including:

Raw-resource extraction impacts on the physical environment for example

cutting down tropical forests for window or flooring timbers, or chemical spills

from poorly managed mines for metal, paint or ceramic products;

Non- renewable resource depletion, including oil, and resource quality

degradation, such as pollution of water;

Greenhouse gas emissions from energy production in all stages of material

manufacture and use;

Waste leading to landfill burdens, including toxic waste.

Looking at the UK, the construction activity is responsible for nearly a third of all

industry-related pollution. Construction and demolition waste alone represent 19% of

total UK waste. Too many buildings are environmentally inefficient and do not make

best use of limited resources such as energy and water. The energy used in

constructing, occupying and operating buildings is responsible for approximately50% of greenhouse gas emissions in the UK (9).

1.3 The Climate Policies: Integrated Assessment Framework

The climate change issue is part of the larger challenge of sustainable development.

As a result, climate policies can be more effective when consistently embedded

within broader strategies designed to make national and regional development


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paths. The impact of climate variability and changes, climate policy responses, and

associated socio-economic development will affect the ability of countries to achieve

sustainable development. Conversely, the pursuit of sustainable goals will in turn

affect the opportunities for, and success of, climate policies. In particular, the socio-

economic and technological characteristics of different development paths will

strongly affect emissions, the rate and magnitude of climate change, climate change

impacts, the capability to adapt, and the capacity to mitigate as illustrated in figure 2.

Figure 2: Climate change - an integrated framework. Schematic and simplified representation of an integrated assessment framework for

considering anthropogenic climate change. Source: (IPCC Intergovernamental Panel on Climate, September 2001)

1.4 The Embodied Carbon in Construction

Life-cycle assessment is a production-based analytical tool used to undertake

embodied energy and carbon analysis. It includes the systematic evaluation of the

environmental aspects of a product or service through all stages of its life-cycle, from

extraction, processing, manufacture, transport and distribution, use, re-use,

maintenance, recycling and final disposal. The concept of Embodied Carbon is not easy to understand and in order to do that

we need to relate it to Embodied Energy as C arbon is often a by-product of the use

of energy.


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Embodied energy is the total energy consumed during the whole life of a product.

Ideally the boundaries would be set from the extraction of row materials (inc fuels) to

the end of the products lifetime (including energy from: manufacturing, transport,

energy to manufacture capital equipment, heating & lighting of factory ...etc), this

definition is known as a Cradle to Grave.

There are two forms of embodied energy in construction as illustrated in figure 3:

A. Initial embodied energy : represents the non-renewable energy consumed in the

acquisition of raw materials, their processing, manufacturing, transportation to site,

and construction. This has two components:

Direct energy the energy used to transport building products to the site, and

then to construct the building;

Indirect energy is the energy used to acquire, process, manufacture the

materials and related transports.

B. Recurring embodied energy : represents the non-renewable energy consumed to

maintain, repair, restore, refurbish or replace materials, components or systems

during the optional life of the building.

Figure 3: Embodied Energy Ladder.

In embodied carbon however, Life Cycle Analysis (LCA) would apply only to specific

stages of the full life-cycle, not covering emissions generated during the use and


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final disposal stages. It is only limited to an assessment of carbon or Green House

Gasses (GHG) emissions, ignoring other aspects of environmental damage. The

Carbon Trust (2006) developed a carbon LCA methodology to assess the carbon

footprint of different products by analyzing the carbon emissions generated by the

corresponding energy use across the supply chain.

In particular the embodied carbon in the life cycle of a building is in the form of CO 2

emitted during the manufacture of materials, their transport and assembly on site, its

maintenance and replacement, disassembly and decomposition.

It consists of 5 main parts as summarised these below and illustrated in figure 4:

1. Design/Project Management carbon (PMc) included in 2 & 3

Carbon created for everything that happens off site from project concept to

completion. This includes travel, administration, all personnel involved in the project:

designers, architects, contractors, suppliers and the client....

2. Material Embodied carbon (Ec)

The amount of carbon within the materials and the constructions of the building:

product sourcing, extraction, refining, processing, manufacture and transportation.

3. Construction carbon (Cc)

The amount of carbon created through the building process: site development,

construction, installation, site equipment, site labour, material delivery, energy used

on site.

4. Operating / Running / In-use-carbon (Rc)

The amount of carbon created by the building over the complete lifespan looking at

each material and product: cleaning, repairs, renovation, refurbishment,

redecoration, maintenance.

5. Deconstruction carbon (Dc)

The amount of carbon created at the end of the building lifespan looking at removing

each material and product.


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Figure 4: Embodied Carbon Ladder.

1.5 Targets for carbon reductions

1.5.1 European Directive in carbon reduction

The Kyoto Protocol to the United Nations Framework Convention on Climate

Change defines the international response to climate change. It contains legally

binding emission targets for Annex I (developed) countries during the post-2000

period. The European Community signed the Kyoto Protocol on 29th April 1998.

Under the Protocol, the 15 European states had been assigned a Greenhouse

Gases (GHG) reduction target of 8% on average over 2008-2012.

The six gases are to be combined in a "basket", with reductions in individual gases

translated into "CO 2 equivalents" that are then added up to produce a single figure.In particular, e ach countrys emissions target must be achieved during the period

2008-2012. It will be calculated as an average over the five years. "Demonstrable

progress" towards meeting the target must be made by 2005. Cuts in the three most

important gases - carbon dioxide (CO 2), methane (CH 4), and nitrous oxide (N 20) - will

be measured against a base year of 1990 (with exceptions for some countries with

economies in transition). Cuts in three long-lived industrial gases - hydro

fluorocarbons (HFCs), per fluorocarbons (PFCs), and sulphur hexafluoride (SF6) -can be measured against either a 1990 or 1995 baseline (7).


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CO 2 accounts for about 80% of the total greenhouse gas emissions from

industrialised countries. For this reasons, carbon emission is probably the most

important issue that has to be actively faced in the near future (11) .

A Burden Sharing Agreement was made in EU as outlined in table 1 below.

Table 1: GHG reduction target under the European Burden Sharing Agreement (1990* - 2008/12)

Austria -13.0 %

Belgium -7.5 %

Denmark -21.0 %

Finland 0.0 %

France 0.0 %

Germany -21.0 %

Greece +25.0 %

Ireland +13.0 %

Italy -6.5 %

Luxembourg -28.0 %

Netherlands -6.0 %

Portugal +27.0 %

Spain +15.0 %

Sweden +4.0 %

United Kingdom -12.5 %* The base year for the fluorinated greenhouse gases can be chosen

as either 1990 or 1995. The base year for all other greenhouse gases

is 1990.

1.5.2 UK target reduction

The UK Government's Energy White Paper (2003) sets an aspiration for the UK to

reduce carbon emissions by 60% and create a low carbon economy by 2050,

accepting the recommendations of the Royal Commission on Environmental

Pollution (RCEP) of a need to stabilise greenhouse gas emissions.

In the near term, agreements following the Kyoto Protocol require the UK to attain a

greenhouse gas emission reduction of 12.5% on average in 2008-2012 compared to

1990 levels. In addition, the UK Government has set its own goal for CO 2 emission

reduction to 20% below the 1990 level by 2010.


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The existing UK Climate Change Programme combines both regulatory and

obligatory measures with fiscal strategy measures to place the UK on a path to

reduce carbon emissions to 60% by 2050 through a combination of energy efficiency

in the short term and renewables in the long term. The Government published a

review of the UK Climate Change Programme in 2006 which set this target. This was

followed in July 2006 by the publication of the Governments Energy Review, a major

review of progress in achieving the following UKs four lon g term goals for energy

policy (7):

To put the UK on a path to cut carbon dioxide emissions to 80% by 2050, with

real progress by 2020;

To maintain reliable energy supplies;

To promote competitive markets in the UK and beyond, helping to raise the

rate of sustainable economic growth and to improve our productivity;

To ensure that every home is adequately and affordably heated.

1.5.3 Birmingham City Council targets

Birminghams Local Area Agreement (LAA) is the document that covers the climate

change issue in the West Midlands.

The new LAA is an agreement between central government and Birmingham - its

people, communities and partners in the public, private, community, voluntary and

faith sectors. It represents a three-year programme to transform the city and to

deliver the first steps of Birmingham 2026: the new Sustainable Community Strategy(13) .

Birmingham has already established its ambition to be a global leader in tacklingclimate change by reducing CO 2 emissions by at least 60% by 2026 and will be

launching its strategy.

Birmingham City Council targets of reducing CO 2 emissions are summarized as

follows:

60% reduction in CO 2 emissions by 2026;

20% reduction in greenhouse gas emissions by 2010;

procure 15% of its energy use from renewable energy by 2010;
http://www.berr.gov.uk/energy/review/page31995.htmlhttp://www.berr.gov.uk/energy/review/page31995.htmlhttp://www.berr.gov.uk/energy/review/page31995.html


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eliminate fuel poverty in vulnerable households by 2010 and in all

householders by 2016.

By exceeding national targets Birmingham will use its expertise, including its science

city status, the University of Birminghams National Energy Technology Institute and

East Birmingham and North Solihull regeneration zone to develop innovative

solutions creating and attracting new businesses and jobs (12) .

However without further actions Birminghams emissions are set to rise from 6.8 to 8

million tonnes per annum by 2026 (13) .

In fact, Birmingham people consume almost three times their fair share of the

Earth's resources, in common with many cities in developed countries. In 2005

Birmingham produced 6,325 kg of CO 2 per person. Carbon dioxide is produced by

businesses (47%), households (35%) and road transport (18%) and action is

needed in each of these areas in order to meet the set target (10) .


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2. Project Aims and Methodology

2.1 Project Collaborators (WMCCE & BCP)The Birmingham Construction Partnership (BCP) was launched in 2004 to

deliver Birmingham City Councils 500 million -plus capital business programme

through to 2009. Le d by Urban Design, the councils specialist building design,

procurement and maintenance consultancy service, BCP brings together the

contractors, GF Tomlinson Birmingham Ltd, Thomas Vale Construction plc and

Wates Group. BCP delivers every council building project over 100.000, the Decent

home standard program, as well as upgrading buildings to DDA standards. BCP is

now the primary means of delivering such works.

The BCP allow the council to source the best quality construction for the

development of the local area. The long term relationship allows all the parties on a

project to be involved from the earliest stage as the first tier of the councils supply

chain. In turn, the second tier is made up of 61 selected companies from whom this

three contractors source specialist service forming a fully integrated supply chain,

unique to a framework of this size in the UK.

Since the BCP was launched 307 projects worth some 489 million have been

allocated to the partners, for service that include housing, offices leisure, sport,

school and social care. The work of the partnership continues to be recognized and

has received a number of prestigious awards, including in 2007, the national award

for Integration and Collaborative

working in the Construction Excellence

Award. The latter is awarded to an

organisation which is changing the way

the UK construction industry works. The

BCP has been so successful that

Birmingham City Council has decided to

extend the initial partnership by two

years until 2011.

One of the ear ly performance drivers for the partnership was to ensure the citys

aspirations towards a more suitable strategy were met. This vision was enhanced in


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2007 when the partnership formed the BCP Sustainability Working Group to ensure

a consistent approach in moving the agenda forward.

Working collaboratively, this core group addressed the challenges of sustainable

development and social responsibility.

A number of common principles are now firmly embedded throughout the framework

and action programmes to achieve sustainable prosperity. Over the past two years,

supply chain allocation by value has exceeded 45 million and with the integration of

environmental, social, human and economic goals in policies and activities

combined, the BCP was able to enhance the sustainability agenda in a number of

key areas:

- The development of opportunities to secure local employment, use of local

supply chain contractors to develop training opportunities and enhanced

workforce profiles for previously under represented groups in the community.

- The impact of sustainability on projects at design stage.

- Consideration of whole life costs whilst maintaining conservation and ecological

integrity.

- Waste management.

- Overcoming financial barriers to sustainability.

2.2 Project Aims

The members of Birmingham Construction Partnership have started to measure

the embodied carbon content of materials and energy used in delivering projects

within the partnership. The intention of this project is to start to produce accurate

data so benchmarks can be established with a view to setting targets for reduction.These targets are to be clearly defined prior to the project commencement in order to

have a clear purpose in every stage of the project. The aims are summarized as

below:

Studying and understanding the issue;

Finding a reliable and easy methodology to measure embodied carbon in the

building construction stage;

Producing embodied carbon data and benchmarks for three case studies;


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Providing recommendations on reduction of embodied carbon in future

constructions.

The first stage of the project was addressed by studying the available embodied

carbon literature because of the high complexity and the newness of this field, as no

similar project was undertaken before. This is the first t ime that a constru ction

companies were directly involved in embodied carbon measurement.

Finding reliable and easy methodology for measuring embodied carbon and starting

to produce benchmarks was one of the main targets which helped to introduce the

issue to the supply chain and to take further technical decisions in partnership. The

BCP is ideally placed to lead this task because of their capacity to influence their

integrated supply chain.

Developing further recommendations to reduce carbon footprint will provide more

reliable results compared to previous targets. This result will be useful for supporting

further research.

2.3 Methodology

This project is a unique survey of embodied carbon in construction that involvesdirectly three contractors. The project schedule was prepared as shown in table 2 in

order to achieve the targets outline in 2.2.

The availability of carbon calculator tools was researched and the most appropriate

tool for construction was selected.

The information needed to calculate the embodied carbon of building materials were

provided in terms of: carbon value per unit weight of material used. The direct

involvement with construction activity provided the opportunity to deal directly withsite managers, project managers, quantity surveyors and suppliers who were

involved in the three building construction projects and with the persons who were

most able to provide the information needed. For this reason the main part of the

survey was based on three placements at GF Tomlinson, Thomas Vale and Wates.

During that period, data was collected for all the case studies and was processed to

reach the results and conclusions of this report.

The first placement at GF Tomlinson took longer than the others to allow for an

adaptation period and to find out an appropriate data collection methodology.


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An interim report to outline and evaluate problems and difficulties encountered was

presented to BCP on 28 th November 2008. The final period was used for compilation

and presentation of the final report.

Table 2: Embodied carbon project schedule

2 5 / 0 8 / 2 0 0 8

0 1 / 0 9 / 2 0 0 8

0 8 / 0 9 / 2 0 0 8

1 5 / 0 9 / 2 0 0 8

2 2 / 0 9 / 2 0 0 8

2 9 / 0 9 / 2 2 0 8

0 6 / 1 0 / 2 0 0 8

1 3 / 1 0 / 2 0 0 8

2 0 / 1 0 / 2 0 0 8

2 7 / 1 0 / 2 0 0 8

0 3 / 1 1 / 2 0 0 8

1 0 / 1 1 / 2 0 0 8

1 7 / 1 1 / 2 0 0 8

2 4 / 1 1 / 2 2 0 8

0 1 / 1 2 / 2 0 0 8

0 8 / 1 2 / 2 0 0 8

1.Work in WMCCE(Climate change, The EmbodiedCarbon in Constructions, Targets forcarbon reductions, Project Aims andMethodology, Measure theEmbodied Carbon, Survey of available tools)

2.Placement with GFTomlinson(Understand data and methodology,case study description, Researchdata input - output, impact, resultsand consideration)

3.Placement with ThomasVales(Case study description, Researchdata input - output, impact, resultsand consideration)

4. Placement with Wates(Case study description, Researchdata input - output, impact, resultsand consideration)

5. Interim Report(Problems and difficulties intools used, Prepare first draft,Consultant with BCP andfeedback)

6. Prepare Final Report(Software Trials Feedback andupdates Conclusion andrecommendation)

7. Presentation of finalreport


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3. Measuring the Embodied Carbon

3.1 Survey of available toolsA web research was carried out to identify available tools. Three suitable

programmes were identified to determine their advantages and disadvantages in

order to select the most appropriated tool for this survey.

The programmes were developed by the Environment Agency, ECCM (Europe's

leading centre of expertise in carbon management) and Wrap (The Waste &

Resources Action Programme). The three programmes are discussed below.

3.1.1 Environment Agency programme

The Environment Agency has produced an online carbon calculator to measure the

impact of construction materials. Working with Jacobs Consultants, the EA has

created an excel spreadsheet which calculates the embodied carbon dioxide of

materials and the CO 2 emissions associated with their transportation.

In particular the tool helps to estimate the CO 2 in the raw materials used, directemissions from personal travel by employees, transportation of building materials

and emissions from site activities such as earthworks and excavation to allow

comparison of waste management options.

It also suggests ways to find potential carbon savings during the planning and design

process and can be used to estimate carbon footprint of a completed project.

As shown in figure 5, the tool contains the carbon value for material which is taken

from: Hammond G & Jones C (2006) Inventory of Carbon and Energy (ICE) Version

1.5 Beta (Department of Mechanical Engineering, University of Bath). This last is a

work realized from Bath University which contains the values of embodied energy &

carbon coefficients. The data was collected from secondary resources (books,

reports, conference papers, web searches...etc). T o aid in the selection of best

coefficients in the ICE-Database that stored relevant information from the literature

(i.e. Country of data, year, boundaries, details of the report, specific comments...etc).


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Figure 5: Extract of Environment Agency spreadsheet. Source: Environmental Agency tool

In particular the tool bases the calculation on four spreadsheets:

1. Construction input: in this section all quantities and transport values for all

material are entered. It also includes the waste removal, plant emissions and

portakabin impacts;

2. Personnel Travel Input: there are three ways of calculating emissions from

Personnel Travel, depending on the availability of the data (if the distance andvehicles used are known);

3. Data: this sheet allows users to override the default values of the tool, where

they have more accurate information;

4. Report: this section summarizes the total result and helps the user to

understand where to find significant carbon savings.

3.1.2 ECCM tool (Europe's leading centre of expertise in carbon management)

The Edinburgh Centre for Carbon Management (ECCM) has developed an easy-to-

use Building Materials Carbon Calculator, which analyses the embodied CO 2 in the

materials used in a building. The tool is the first of its kind and it helps decision

makers to select the best material to minimise the carbon footprint in a building. The

calculator helps clients, architects, builders and developers to gain an understanding

of the environmental impact of their projects at the concept stage. The tool is a


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simple to use and understand, designed to clear the haze surrounding calculating

the carbon in building materials.

Figure 6 shows how the building elements are compared within the tool. This

includes foundations, external walls, roofs, cladding, floors, insulations, internal

walls, windows and doors. This division simplifies the data entery because it

represents the main elements of a building, some of which are included in the bill of

quantities.

Figure 6: Extract of ECCM carbon calculator. Source: ECCM tool

The Carbon Calculator provides a reading of the embodied CO 2 in each of the

building elements. Once quantities for all the project elements have been input, an

overall indication of the carbon footprint of the building is provided. The software also

encourages users to reconsider and compare the materials they select in order to

reduc e a buildings carbon footprint in the decision process.

3.1.3 Wrap tool (The Waste & Resources Action Programme)

This is carbon dioxide (CO 2) emission estimator tool for the aggregates used in

construction. It is a Microsoft Excel based to help users decide upon construction

techniques and aggregate supply alternatives on the basis of the associated CO 2

emissions. The tool has been developed by TRL Limited, Costain and Taylor

Woodrow Technology under a contract from WRAP on the basis of earlier models

which only considered single area of construction. The tool is designed to assess the


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CO 2 output resulting from four types of construction involving aggregates: bitumen

bound, concrete, hydraulically bound and unbound.

Figure 7 shows that for each construction type, the estimator tool allows up to three

options to be compared. The options would be alternative mixtures with varying

percentages of recycled and secondary aggregates (RSA) or techniques that the

users know are fit for the same purpose.

Figure 7: Extract of WRAP: carbon calculator. Source: WRAP tool

The tool estimates CO 2 emissions for each option and then compares the second

two options with respect to the first, which used as a base case scenario to highlight

any CO 2 savings.

Users can access the background calculations, where the CO 2 from the different

processes are estimated (e.g. embodied energies, transport, construction

techniques) and the data used. This enables the users to:

1. Identify areas for major savings or contributing most to the overall emissions

(e.g.: transport modes, transport distances, techniques including choice of

binders, etc.) and quantify the corresponding savings in CO 2 emissions;

2. Introduce data on their own equipment processes and materials.


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3.2 Selecting the most appropriate tool

In order to select the most appropriate calculator for this project, table 3

shows the advantages and disadvantages of each tool to clarify how the most

appropriate tool has been selected.

Table 3: Advantages and disadvantages of the tools selected. Sources: Author

TOOLS Advantages Disadvantages Comments

ECCM(EdinburghCentre forCarbonManagement)

Spreadsheetorganization

Simple andIntuitive to use

Fast data entry

Does not consider plantemission, travel andtransport in general

Can not be used forcomparing similar material

Fewer options

Inflexible

Good to understand beforethe project start up but notreliable for benchmarkingand accurate measurement

WRAP (MaterialChange forBetterEnvironment)

Accurate tool Possibility to

compare theimpacts of differentkind of aggregate

Considers only aggregatesmaterial and relatedtransport

Not intuitive and difficult touse

Good tool to comparebetween different type ofaggregate and differentmaterial origins but it ismore oriented to urbaninfrastructure (street ...)

EnvironmentAgency Tool

Covers the impactsof the building and

related activities Returns separate

impact by materialtype

Not intuitive and difficult touse

Can not be used forcomparative purpose

Good tool to calculate thetotal building embodied

carbon by considering allrelated activities(benchmarks). This tool hasbeen adopted for thisproject with modification.

Table 3 indicates that simplicity of the ECCM calculator is good to understand the

carbon impact before the project starts but is not reliable for benchmarking and

accurate measurement.

The WRAP calculator is a good tool to compare between different types of aggregate

and different material origins but is more oriented to urban infrastructure projects and

is not intuitive to use.

The Environment Agency calculator is considered a more suitable tool to estimate

the total building embodied carbon. It considers all related activities and therefore is

useful for benchmarking. Unfortunately this tool cannot be used for comparative

purpose and is not intuitive to use.

By comparing the characteristics of every tool with the project targets, the

Environment Agency calculator was selected as the tool for this project.


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3.3 Embodied Carbon Information and Sources

In order to understand which data are needed for assessing the total embodied

carbon in building construction, the information requested and sources are outline in

every stage of the carbon ladder as shown in table 4.

1. Waste mass and mileage travelled from one place (extraction site,

manufacture, whole sale, suppliers and project site) to the landfill;

2. Material mass and mileage travelled from one step site to the next one;

3. Carbon produced by transforming the material from one form to another;

4. Workers daily personal travel to reach the construction site;

5. Plant emissions in terms of diesel, biodiesel, electricity, gas and water use.

Table 4: "Embodied Carbon" Information and Sources.

This information was collected from the following sources:

1. Waste mass: the mass was provided from the project manager or from the

suppliers whereas the distance to the landfill was estimated by using Google

map;


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2. Material mass: the material mass was taken from the bill of quantities, the

order sheets or from the project managers and suppliers information. Miles

were estimated by using Google map;

3. Transformation process: this value was taken out from the Inventory of

Carbon & Energy by University of BATH or from information provided from the

suppliers.

4. Personal travel and plant emissions: were assessed by using the estimator

present in the Environment Agency tool that calculates the carbon impact by

entering the total size of the project.


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4. Estimating the carbon footprint in three case studies

4.1 GF Tomlinson case study4.1.1 GF Tomlinson Group: Company profile

G F Tomlinson Group provide a full and comprehensive construction and civil

engineering service to valued Clients and Partners in both the public and private

sectors. From offices in Derby, Birmingham and Worcester G F Tomlinson Group

cover the majority of the Midlands and South Yorkshire, dealing with a multitude of

differing types and sizes. Its activities regard not only the full range of buildingservices but also design & build, joint venture and collaborative arrangements

bespoke tailored to the specific needs of the project and Client.

The Holding Company was established in 1980 to provide management services in

terms of financial control, human resources, marketing and its Integrated

Management System. The Group also sets operational standard that are common to

all of the expanding Tomlinson divisions.

The Building division of the Tomlinson construction group undertakes individual

projects within a 75 mile radius of Derby. Working in the commercial, industrial,

healthcare, education, leisure and retail sectors, the company provides a full range

of construction services in new build, refurbishment, restoration and building

maintenance. Together with a well established reputation in design and build,

traditional and management contracts, over 65% of operations are now collaborative

working arrangements/ partnerships with a range of key clients in the new build,

building refurbishment and maintenance sectors.

The civil engineering division has provided a comprehensive construction service

throughout the Midlands for over 100 years. Current projects are as varied as they

were during the formative years, covering roads, bridges, water treatment and

sewerage schemes, land reclamation, industrial and commercial work and

infrastructure projects for development schemes.

The construction group's Birmingham-based division mirrors the activities and

achievements of the Derby operation, working on projects ranging from several


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thousand pounds to several million pounds within the Birmingham and the West

Midlands area.

G F Tomlinson Group currently employ and train over 500 staff and tradesmen and

regularly employ around 400 specialist subcontractors and suppliers at any one time.

The majority of suppliers form part of their established supply chains, where

performance is constantly audited through their Integrated Management System

(IMS). Over this year, concerning the environmental issue, G F Tomlinson has the

objective to improve their waste management, increase the amount of waste

recycled and increase subcontractor awareness and commitment by fixing a target of

recycled waste to 80% and an increase in subcontractor positive response to 10%.

4.1.2 Colebourne primary school case study: construction site description

G F Tomlinson case study is a primary school which accommodates a total of

460 pupils. The site is located in the residential area of Stechford on the eastern side

of Birmingham. The work relates to the construction of a new fully inclusive primary

school on land behind the existing Colebourne School on Stechford Road, Stechford,

Birmingham. In particular, the new school will accommodate existing pupils and

those from Beaufort Special School in Stechford. Beaufort is a school for pupils with

severe learning difficulties aged 4 to 11 years, currently in Coleshill Road, Stechford.

Bringing the two schools together on a one site will enable pupils from the special

school to experience mainstream school life, as indicated by Cllr Les Lawrence,

cabinet member for education and life-long learning (Engineer, 21 November 2007).

Parts of this works involve construction on land designated greenbelt and as such

the environmental aspect takes specific heightened attention. The consultant

architects are Birmingham Coun cils Urban Design. In li ne with councils ex isting

partnership agreement, GF Tomlinson Building Limited will oversee the construction.

The construction is taking advantage of the latest technology in off-site fabrication

which will minimise disruption and reduce construction time. The project began in

August 2007 and is expected to be concluded by August 2009. It is expected that the

main building construction will end by February 2009 followed by demolition of

existing building and refurbishment for further eight weeks.


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Figure 8: Colebourne primary school case study. Source: GF Tomlinson

The main build programme takes 65 weeks directly after the enabling period. The

project involves the construction of a new two storey education facility comprising:

classbases, corridors, administration areas, specialist hydrotherapy pool, plant

rooms, two assembly halls, meals kitchen together with numerous specialist rooms

servicing the requirements of Beaufort pupils.

The main technical elements of the building include in: raft foundation, structural

steel frame, hollowrib composite first floor, green roof, steel staircases, internal and

external brickwork walls, sto-render or larch timber claddings.

The building is characterised for an environmental regard (in line with DFES fundingrequirement) being designed with particular technical solution as a green roof

(sedum onto sanding seam roof) and mechanical - electrical installations that provide

natural ventilation and natural lighting.

Further sustainability has been considered for energy, waste and water efficiency -

minimization during the build construction period. In support of this issue, expedients

studies were taken, such as: materials are ordered in minimal quantities required

and are stored in a way which prevents damage and unnecessary waste. Buyerconsider the purchase of materials from suitable sources whenever possible and


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measures are taken to minimise use of water using water minimising controls (ex:

low flush toilets, cistern displacement device, sensor urinal flushing control etc),

signs are provided to make persons conscious of environmental issues.

Consideration has been taken for the importance of energy conservation and

efficiency (ex: sign and sensor will be provided in order to reduce the unnecessary

use of lighting / persons working on site are aware of an energy careful use of the

equipment).

Choosing this technical solution aims to achieve a very good BREEAM rating (BRE

Environmental Assessment Method).

During the placement period at Colebourne primary school (during the middle of

September 2008), the building construction followed the activities schedule.

4.1.3 Research: data input - output, impact, results and consideration

4.1.3.1 Data Input - Output

GF Tomlinson case study has been developed by collecting the data from the

Bill of Quantities provided by the assigned quantity surveyor.In order to calculate the carbon footprint: the embodied carbon and the quantity used

(in tonnes) of each element or material are required. In order to measure material

used in tonnes, the material density was utilized. The final quantities were input into

the Environment Agency tool which contains the embodied carbon for most materials

used. Components were split up as far as possible to measure the embodied carbon

in its elementary material. For some materials this operation was not possible

because the embodied carbon of the elementary material was not available in theEnvironment Agency tool and the suppliers were not able to provide that information.

The huge amount of information needed to calculate the carbon footprint through the

total life meant that the data input could not be completed. In fact, calculation of the

carbon footprint did not consider all the activities from the beginning of the project

due to the activity called External Timber Cladding. That activity was accomplished

in the middle of June 2008.

More attention was placed on the material embodied carbon rather than ontransportation impact, plant emission, personal travel and waste disposal. More


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focus was placed in that direction because the result was more sensitive to the

material embodied carbon.

The plant emission and the personal travel impact were considered using the

calculator placed in the environment agency tool that provides an estimation,

knowing the project size and duration. The waste removal impact was considered

using the total tonnage produced and the distance between the site constructor and

the landfill location.

The material embodied carbon in the E.A. tool was split up in many sections relevant

to the bill of quantities sections: Substructures, Frame, Upper Floors, Stairs, Roof,

External and Internal Walls, Windows and External Doors, Partitions, Internal Doors,

Finishes, Fittings and Furnishing, Work to Existing, Site Works and Drainage. Never

the less the case study was not completed and the analysis stopped at External and

Internal Walls activities. In such way the calculation of the total carbon footprint was

easier as the data entry came directly from the bill of quantities . The Total

Construction I nput summarizes the value in one single spreadsheet whereas the

Report spreadsheet shows final results.

4.1.3.2 Results and Considerations

A total value of 1331 tonnes of CO2 was measured by the Environment Agency tool.

This value is not the final result but only part of it, because of the amount of data

involved in the calculation. However, some comments can be made as the value

relates to the main activity in the building construction such as foundation, elevation,

internal and external wall and roof which involve about 80% of the total construction

process.


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Table 5: Colebourne primary school "Embodied Carbon Indeces".

DATA TOTAL INDECES

CO 2 1331 t -

Cost 10 million 133.1tCO 2 / mln

Weight 4178 t 0.454tCO 2 / t material

Gross Internal Area (GIA) 2930 m 2 0.454tCO 2 / m 2

Figure 9: Colebourne primary school footprint estimation results

Figure 9 shows the distribution of CO 2 in the school building. In particular, it shows

high impact for Concrete (33%, 438 tonnes CO 2) and metals (28%, 375), compared

to Plant emissions (12%, 174), Quarried material (11%, 142), Personal travel (6%,


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88) and Plastics (6%, 86). It is important to highlight that the impact of personal

travel and plant emission are estimated from the tool and are not the actual emission

produced in the project. Moreover, it is possible to say that quarried material and

plastic will be higher in the remaining activities which contain a higher proportion of

that kind of material. Generally, results show that concrete and metals together

represent 61% of the total carbon footprint of the building envelope. Table 6 shows

the results in more details.

Table 6: Colebourne primary school embodied carbon. Materials Impacts Material

CategoryMaterial

Mass(Tonnes)

TonnesCO 2

(1)

% oftotalCO 2

t CO 2 / t ofmaterialcategory

Major applicationof material in

category

TonnesCO 2

(2)

% oftotal

(2)/(1)

T CO2(2) / total

CO 2

Concrete,Mortars &Cement

3636.6 438.1 33% 0.120XC2 Concrete(C30) 377.4 86% 28.36%

Metals

231.1 374.7 28% 1.622

Substructures(wire steel) 100.4 27% 7.55%

External-Internalwalls galvanisedsteel

88.3 24% 6.64%

Frame 59.1 16% 4.44%

Roof (ribdeck -Decking) 55.4 15% 4.16%

Quarried

Material228.7 144.7 11% 0.633 Facing Bricks 121.3 84% 9.12%

Plastics

55.8 86.0 6% 1.543

Roof SoundInsulation Mineralwool

48.3 56% 3.63%

Roof EchothermInsulation (UK) 23.3 27% 1.75%

Timber 39.2 21.2 2% 0.540 Roof Timber 18.6 88% 1.40%Total 4191 1065 80% - - 892.1 - 67.05%

Table 6 shows that the highest impact comes from Concrete and Metals. It is worth

noting that Concrete type XC2 has 86% of the total embodied carbon in the concrete

used. Other relevant measure is noted in the value of CO 2 substructures andexternal - internal walls galvanised steel which represent 51% of the total CO 2 in

steel. This means that the impact of concrete reinforce is significant. Another

relevant value is represented in facing bricks which have no structural function yet

have a high environmental impact (in terms of embodied carbon). From these

considerations it is possible to say that in buildings with these school characteristics,

concrete would be the first consideration in reducing CO 2. Attention should be made

not only to the used of aggregate and cement, but also to the type of steel


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reinforcement. Further reduction could be gained by a limitation on facing bricks

used and by choosing bricks with a low embodied carbon.


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4.2 Thomas Vale case study

4.2.1 Thomas Vale Group: Company profile

Thomas Vale Construction was established over 150 years ago by a young

Victorian engineer Thomas Vale . The first of the companys many projects was to

construct the unique cast iron bridge spanning the river at Stourport-on-Severn. The

bridge still stands and supports the cast iron shields on each spandrel which form

the basis of the Groups corporate identity.

Thomas Vale Construction is part of the Thomas Vale Holdings Group and employs

a direct workforce of just over 500 people, and has nearly 80 active constructionsites throughout the UK.

The company is growing fast and in 2006 saw turnover increase by 28%. The

company employs subcontractors which can boost its total staff numbers by up to

2,000 people. Thomas Vale Group of companies has currently an annual turnover

approaching 200 million, with clients from both Public and private sector.

The head office is based in Worcestershire and with Region Centres, based in

Birmingham, Dudley, Wolverhampton, Stoke on Trent, Nottingham, Leicester andReading, Thomas Vale can provide localised delivery with established professional

teams and long established supply chain who share their values and commitment of

service.

The company has welcomed and fully embraced the objectives and

recommendations of various Governmental Reports to modernise construction and

to focus on greater efficiency across all of their operations, excellence and

exemplary service.

Today, around 70% of Thomas Vale workload is undertaken on Long Term

Frameworks and Partnerships. They have developed a unique knowledge of working

within these types of project, often spanning up to 5 years.

However, Thomas Vale still secures around 30% of its work through the traditional

route off competitive tendering. This ensures that they are aware of the marketplace

and can provide overview and analysis to benefit Clients, in all theirs preferred

procurement route.


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Thomas Vale has always placed special attention to Design and Build, Construction,

Maintenance, Education, Healthcare and Requirement, New building, Rail, Industrial

and Commercial Interiors, Facilities Management, Social Housing, Regeneration and

Piling.

4.2.2 Sutton New Road Offices, Erdington: construction site description

Thomas Vale case study concerns 67 Sutton New Road (see figure 10), a key

landmark building for Birmingham City Council and is the first visible phase in the

Councils Working for the Future business tr ansformation programme.The brief was to create a modern, efficient and flexible building that could be

occupied by staff who was previously based in existing, outdated accommodation at

Lancaster Circus and Orphanage Road. This project was required to play a vital role

in the councils aim of relocating staff away from the city centre in accordance with

their regeneration policies.

Figure 10: Sutton New Road Offices, Erdington.Source: Thomas Vale

The building is characterized for a high quality features such as a lightweight metal

framing system that reduces foundation loading and ensures that the building fabric

is highly insulated and air tight.


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To ensure that the 6m project was delivered to the agreed timescales,

specifications and budgets, Thomas Vale Construction had been working closely

with the client Urban Design.

The whole life cycle was an integral part of the design concept of this building,

together with an achieved very good BREEAM rating. In fact, a lot of emphasis was

placed on the construction techniques and methodology with a strong reference to

environmental issues. As well as using recycled rainwater (for flushing WCs) to save

approximately 1,400 m 3 of water per annum and a solar heated hot water system

installed on the roof, the building uses an innovative approach to ventilation.

The major challenge for the project was to achieve a natural ventilated building

without using air conditioning. For this reason, Sutton Road office uses dedicated

and automated ventilation units. These units operate automatically to provide

outdoor air for the occupants, and to help control the temperature in the offices

during warm weather. The ventilation is also designed to work in conjunction with the

building structure to further improve the office temperature during the summer. The

ceiling structure in most of the office areas has intentionally been left exposed, and

by using the ventilators, cool the structure overnight. The temperature will remain

more comfortable the following day, as heat from equipment, occupants, and solargain, is absorbed by the structure, rather than heating the space. The system is

designed to provide comfortable condition for the majority of the year and is set up to

operate automatically. The ventilation can also be controlled manually using the

override switches provided in each working area.

The completed scheme will benefit from a low Carbon Footprint for a building of

this size, having been designed from outset as a model for minimising carbon

emission and lower long term running cost.


4.2.3.1 Data Input - Output

Analysing a finished case study gives us the possibility to avail our self of

effective final data that can be reliable. In fact, this study has been based on theorders register which is completely consultable through IntraVale, the information


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integrated system utilized by Thomas Vale staff. It is possible to find any information

regarding companys projects in detail such as: project details, project staff, staff

history, traders and materials order details.

Thomas Vale case study has been set up a different way because of the different

source of the data. For every order, the material supplied were detailed in terms of:

Order Description, Order Number, Company, Number of quantity Dimension,

Volume, Quantity (m 3, m 2 or m), Density, Weight (tonnes), t CO 2 /t material, Total

embodied carbon, Distance of the supplier and category (metals, wood...). That

information was introduced in the other material section in the construction input

spreadsheet of the Environmental agency tool. This gives us the total building

construction carbon footprint and the value for any category.

As in GF Tomlinson case study, the plant emission and personal travel have been

considered using the calculator placed in the environment agency tool that provides

an estimation knowing the project size and duration. The waste removal impact has

been considered using the total tonnes produced and the distance between the site

construction and the landfill.

Some difficulties were encountered where the order covered work and material

supply. In this case the order sheet doesnt show the quantity of material but thedescription of the supplied activity. The calculation in this case was based on the

data in the bill of quantities as supplied by the project manager.


A total value of 1043 tonnes of CO 2 is registered from Environment Agency tool. It is

possible to consider this value to be reliable as its estimation was made considered

order sheets. Further studies can be done in order to estimate the emissions

generated by the transport from the material origin to the supplier stock site. Figure

11 shows the embodied carbon values for all material categories.


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Table 7: Sutton New Road Offices "Embodied Carbon Indeces". Source: Author

DATA TOTAL INDECES

CO 2 1043 t -

Cost 6 million 133.8tCO 2 / mln

Weight 2640 t 0.395tCO 2 / t material

Gross Internal Area (GIA) 4050 m 2 0.2575

tCO 2 / m 2

Figure 11: Sutton New Road Offices footprint estimation results

As is shown in Figure 11, Metals, Concrete, Plant emission , Quarried material and

Personnel travel have high impact on the total embodied carbon. It is important to

emphasise that the metal value (38%, 401 tonnes CO 2) is much higher compared to


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the others: Concrete (19%, 198), Plant emissions (16%, 168), Quarried material

(10%, 99.1), Personal travel (8%, 84.8) and plastic (2%, 21.6). As already

mentioned, it is important to highlight that the impacts of personal travel and plant

emissions are estimated from the tool and are not measured from emissions

produced in the project.

Further consideration has been made for this value in order to determine the highest

impact of materials. Table 8 shows the results of this analysis.

Table 8: Sutton New Road Offices embodied carbon. Materials Impacts MaterialCategory

MaterialMass

(Tonnes)

TonnesCO 2 (1)

% oftotalCO 2

t CO 2 / t ofmaterialcategory

Major application ofmaterial in category

TonnesCO 2 (2)

% oftotal

(2)/(1)

T CO 2 (2) /totalCO 2

Metals

215.2 401.3 38% 1.865

Structural SteelFrame Mild steel 364.0 91% 34.90%

Reinforcement A252mesh, 4.8m x 2.4msheets

20.9 5% 2.00%

Concrete,Mortars &Cement

1615.4 198.1 19% 0.123Concrete C35

158.6 80% 15.21%

QuarriedMaterial 721.0 99.1 10% 0.137

Quarried MOT type 1 42.0 42% 4.03%

facing Brinks 16.7 17% 1.60%

Timber

66.6 41.8 4% 0.628

Timber & tile lath - 6"

x 2" roughsawntimber 21.3 51% 2.04%

Total 2618.2 740.3 71% - - 623.5 - 59.8%

Table 8 shows that the Structural Steel Frame contributes to 34.90% of the total

building embodied carbon and represents 91% of the total metals. This high value

registered by the steel is because the main structural frame is made of steel. Steel

has a high embodied carbon and that makes its impact more significant. On the

other hand, it is important to underline that a steel frame means less weight on the

substructure and therefore less foundation and less use of heavy concrete. Concrete

has a lower embedded carbon per unit weight of material but it is used more. This

results in a high total carbon footprint. In this case study the concrete used is C35

which contains higher percentage of steel reinforcement. These observations are not

valid unless the origin of material is considerated. It is probable that steel material

comes from outside the United Kingdom whereas most elements in the concrete,

apart from the reinforcement, are more likely to be sourced from the UK. Further

researches need to be done in order to quantify these points.


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4.3 Wates case study

4.3.1 Wates Group: Company profile

Wates has been providing construction services since Edward Wates and his three

brothers began building houses in 1897. The group, still family-owned, has

expanded to offer a large range of construction and development services, including

building maintenance and facilities management, interior fit-outs, renovations, and

real estate development. It works on commercial, industrial, and institutional projects,

including shopping centers, schools, prisons, and social housing.

During the Second World War, the company developed speciality in constructingpre-cast and in situ reinforced concrete barges and floating docks. After the War the

company used this knowledge of pre-cast concrete to develop high-rise and low-rise

industrialised housing systems and built over 60,000 houses and flats using these

techniques.

Wates group is currently structured with five core businesses:

- Living Space: refurbishing existing affordable homes and building new ones

across the UK- Construction: building education, commercial and government facilities and

refurbishing historic buildings

- Retail: providing fit-out and refurbishment services across the UK and Ireland

- Interiors: delivering office fit-out and refurbishment services across the UK

- Developments: enhancing the value of land and working in selected joint

ventures with major house builders

In particular, this case study analyzes refurbishing existing affordable homes across

the UK as part of Living Place Division core business. Wates Living Space builds

new homes, refurbishes existing properties and manages regeneration schemes

across England and Scotland. Wate s Living Space is one of the countrys leading

affordable housing contractors and one of three partners working with Birmingham

City Council to improve the 68,000 homes in its public housing stock. Since the birth

of the Governments Decent Homes Programme Wates has been a leading

contractor in large-scale home improvement projects. Wates is now working with 24


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customers within long-term partnerships, using local labour wherever possible and

recruiting around 75% of staff on these projects from the local community.

Wates shares knowledge through their nationwide best practice network to ensure

that the customers benefit from their experience right across the country. By working

together with neighbourhood partners Wates helps to address a wide range of issues

and achieve sustainable and vibrant communities.

4.3.2 Case study description

Wates case study analyses a typical three bed house refurbishment in line with the

Decent Home programme. Information in the case study was provided by Wates

Living Space Midlands which is based in Sovereign Road, Kings Norton. To

understand the meaning of the study and the reliability of its information sources, it is

useful to provide some background on Decent homes. Decent home provides

modern standards relating to fitness, structure, energy-efficiency and facilities. The

government wants all social housing in the United Kingdom to be brought up to the

Decent Homes standard by 2010. To achieve that goal, a partnerships and networks

were developed between local authorities, developers, suppliers and communities.

In particular the concept of Decent Home meets the following four criteria:

a) Current statutory minimum standard for housing;

b) Reasonable state of repair;

c) Reasonably modern facilities and services;

d) Reasonable degree of thermal comfort. This criterion requires dwellings to have

both effective insulation and efficient heating.

According to the above criteria, Wates case study considers a full refurbishment in

order to cover all main activities Wates Living Space provides. According to Decent

home programme the case study was considered a poor condition home and Table

10 shows the criteria which describe that definition.
http://www.nihe.gov.uk/index/about-us-home/our_objectives/decent_homes_standard.htmhttp://www.nihe.gov.uk/index/about-us-home/our_objectives/decent_homes_standard.htm


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Figure 12: Communities and Local Government: A Decent Home - Definition and guidance for implementation, (Government, June 2006).

The case study involves activities such as: RSF, Windows and Doors, Insulation,

Roofing, Painting, Electrics and Central Heating. Because of the different conditions

and sizes of dwellings, an average was considered for the material involved.

Wates case study is different from that of GF Tomlinson and Tomas Vale cases

because it considers the refurbishment activity rather than new building construction.

The data collection was easier because less work activities were involved.

It considers eight components compared to a whole bill of quantities, which provide

an opportunity to pay more attention to each single component. Despite that, there

was high sensitivity in the embodied carbon value of one component on the total

value because of the huge amount of dwelling refurbishments. Due to this, the

component and material suppliers were directly involved in the analysis.

Figure 13: Wates Case Study. Wates Living Space


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Transport impacts were considered in the distance between the material suppliers

and Wates Living Space Midlands office. The transport emissions caused by the

travel from Wates office to the site construction was not considered as the case

study is not a real activity but a hypothetical situation that considers the average of

many refurbishment activities. However the transport impact could be considered as

reliable as the biggest impacts are generated in the first transport and only a little

part in the second.


4.3.3.1 Data input - output

Wates case study has been developed considering eight refurbishment components.

A proper spreadsheet has been set up for every component and elementary material

found. For every component the following was registered: the description, company

supplier, quantities in metres and number, density per unit and kg, quantity in

tonnes, embodied carbon, distance between supplier to stock site and distancebetween element origin to supplier. Suppliers were asked to fulfil the spoken pattern

and once received the data was compiled in a spreadsheet, c alled Material data

input. A link between this last and the construction input spreadsheet has been

developed in order to find out the carbon footprint for the total refurbishment and for

all categories.

Because the analysis has been done on a hypothetical case, personal travels and

plant emission were estimated using the tool provided from Environment Agency.Further analysis could be made in order to provide more specific values. Personal


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transport, in any single refurbishment was generically considered since suppliers

change every time. Plant emission calculation will be possible to measure in any kind

of refurbishment by considering the Energy bill paid during the work period.


DATA NOT AVAILABLE


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4.4 Evaluation of Results

4.4.1 Problems and difficulties in tool used and the data collection

As mentioned before many problems came out in the carbon calculation because of

the unexplored application. Difficulties were found in the use of the tool, because its

complexity and organization. In particular, the problems encountered are

summarizing as following:

Difference between the data required for the tool and available data (bill of

quantities and the order sheets). The tool was not built to accommodate the

format of a bill of quantity nor the order sheets. All the data are saved in thetool in the same spreadsheet which causes confusion and possible mistakes;

The material quantities have different units of measurement. The tool requires

the material quantities to be in tonnes whilst the bills of quantity are in various

different units (i.e. unit, m2, m3. ml etc...);

The embedded carbon values utilized from the tool is an estimation made

from the Inventory of Carbon & Energy by the University of BATH and not

direct from the sources. The information available is in terms of embedded

energy rather than embedded carbon. And thus, the total embedded carbon

value can only be considered an estimation not the real value;

The tool doesnt consider the embedded carbon in the waste generated. The

calculation based on the bill of quantity cannot provide a good estimation of

the embedded carbon in the building live cycle. The order sheets can provide

a better estimation of the actual material used;

The tool doesnt consider the suppliers location in order to estimate the

transports impact particularly if the material is provided from different

suppliers;

The tool considers only elementary material and not the building components

therefore these components must be split up in its elements (windows,

doors...);

The method only considers the CO 2 impacts and ignores the impacts of the

other 5 Gasses. It is worth noting however that CO 2 emissions constitute

around 80% of the total impact of green gasses.


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4.4.2 Review of methodologies used

Table 10 shows, for each case study, the sources of information used. As is shown,

University of BATH was the main source for the process embodied carbon. Only inWates case study the suppliers information was used as far as available by directly

approaching them.

The assessment tool provided by the Environment Agency was used in all case

studies to determine personal travel and plant emission.

The material and waste transport were estimated using the information provided by

the project manager and suppliers using Google map.

Pro ject managers information was used to assess the use of materials; however

every case study was based on different approach. The information in Waste case

study was based on suppliers information, GF Tomlinson case study was based on

bill of quantities and Thomas Vale case study was based on order sheets as shown

in Table 10.

Table 10: Sources and Methodology used each case study.

Data

requested

Type of process and

Source of information

Wates GF

Tomlinson

Thomas

Vale EMBODIEDCARBONSOURCES

Process Embodied carbon*(Inventory of Carbon emission) X X X

Process Embodied carbon(Suppliers) X

Personal Travels and PlantEmissions (Estimation EA tool) X X X

Material Transport (Google Map) X X X

Waste Transport (Google Map) X X X

QUANTITYSOURCES

Suppliers X

Bill of quantities X

Orders Sheets X

Project manager information X X X

As is shown in Table 11, using three different approaches has provided the

possibility to examine the following aspects:

Basing the analysis on the bill of quantities enable modification of theEnvironment Agency tool in order to facilitate the data saving. Each bill of


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quantities entry lead to a bespoken spreadsheet in the environment agency

tool in which all the material quantities and carbon value were summarized. A

spreadsheet was adapted in the original data entry spreadsheet of the tool,

titled construction input spreadsheet . This methodology makes the data

saving more intuitive and reduces possible human error.

Basing the analysis on order sheets provided reliable benchmarks as the

value of material quantities were not the same assessed at the beginning of

the project, but those registered on the order sheets. The data was compiled

by entering all the information in the other materials sect ion, placed in the

construction input spreadsheet of the Environment Agency tool.

Basing the analysis on supplier information enabled collection of the

component data provided from the suppliers and reliable benchmarks. A

bespoke spreadsheet (showing information on the material quantities,

distance from the site and carbon value), was established and forwarded to

the suppliers. All the information was collected in the other materials section

placed in construction input spreadsheet of the Environment Agency tool.

Collecting the information directly from the suppliers was used to generate

reliable benchmarks.

Table 9: Data Input and Output for each case study.

DATA GF TOMLINSON THOMAS VALE WATES

INPUT

Collect quantities data from

Bill of quantities

Split up the EA Construction

input spreadsheet following

the bill of quantities index Summarize all in Total Input

spreadsheet

Collect order sheets

from Intravale system

Enter all the data in the

EA other material

spreadsheet

Collect information from Suppliers

Build a spreadsheet for any

component showing the

quantities and embodied carbon

Enter all the data in the EA other material spreadsheet

OUTPUT

Approach to the Carbon

footprint calculation

Method to collect materials

data using bill of quantities

Results

Consideration (by analysing

results)

Method to collect

materials data using

orders sheet

Reliable Benchmark

Results

Consideration (by

analysing results)

Method to collect component

data using suppliers information

Reliable benchmark

Results consideration (by

analysing results)


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4.4.3 Result Consideration and recommendations

The research produced many interesting outcomes, which lead to the following

considerations:1. Company GF Tomlinson and Thomas Vale case studies, both used new buildings

in frames made of steel. GF Tomlinson case study was a one floor building while

Thomas Vale case study was made of four floors building providing different impacts

from the substructures and frames. In particular from these two case studies analysis

the following can be made:

a. Steel has the highest embodied carbon per unit weight of material used

although a steel frame has less weight and therefore requires lighter

foundation.

b. Concrete has a lower embodied carbon per unit weight of material than steel

but it is used in larger quantities. This results in a high total carbon footprint

for the frame. The C35 concrete is used more often and it contains a higher

average of steel reinforcement.

c. Face bricks have high impact per unit mass and this, combined with a high

use (like in GF Tomlinson case study), have strong effect on the total result.

Choosing low carbon bricks and limiting their use could strongly decrease the

total value.

Further studies will be needed to compare the different impacts of steel and concrete

frames (same building with different frame) and by using different types of face

bricks.

2. Refurbishment case study is considerably different from new construction as more

focus is placed on the use of components more than materials. The total embodied

carbon in new construction is sensitive to the use of materials (as steel and cement),

whereas in refurbishment it is more sensitive to the embodied carbon in individual

components. For this reason, it is important to pay attention to the embodied carbon

value of components in order to minimize the carbon impact. Unfortunately it wasnt

possible to calculate the payback carbon time because the value of annual carbon

saving wasn t found out. Collecting this last and basing the calculation on the total

embodied carbon already found, it will be possible to calculate the needed time to

payback the major embodied carbon caused from the refurbishment.


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3. There are substantial differences between recycled materials and new materials

regarding the contribution of transport CO 2. In fact, the previous considerations were

made without including the transport from the origins of material to the UK. Only

transport in the UK was considered in the impact on the total embodied carbon of the

building. The benefits of using recycle material can be significant in the UK because

it avoids the carbon footprint of new material with a much reduced impact on

transport. This is illustrated in using recycled concrete and steel which come from

UK compared to new material which are imported from other countries.


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5. Conclusion

5.1 Reducing problems and Improving on advantagesReducing CO 2 emission is a delicate topic because it is an untouched field and

because of the complexity caused by the various disciplines. This research involved

a novel approach of involving applications by construction companies for the

measurement of embodied carbon.

This project was based on understanding the Environment Agency tool. During the

research were come out difficulties and problems in the use of this tools that are

shown in paragraph 4.4.1. Little modifications at the tool were done in order to

simplify the data saving process and reduce human mistake. This modification could

be considered temporary because the calculation is still complicated but is a good

base for further software improvements.

Within this project are come out methodologies and benchmarks that are only the

beginning of a long research that should involve and join more people and skills in

order to establish more appropriated methodologies and reliable benchmarks.

New methodologies for calculating the embodied carbon in new building construction

and refurbishment are come out. In the new building construction is important to pay

attention to the most used material, such as concrete and steel, but also on material

with high CO 2 embodied carbon such as face bricks and Insulati

embodied carbon in construction in wm

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