College of Engineering & Informatics
Sustainability and Embodied
Energy (and Carbon) in Buildings
Dr Jamie Goggins | Lecturer in Civil Engineering
Affiliations:
College of Engineering & Informatics, NUI Galway
Ryan Institute for Environment, Marine & Energy Research
IBCI Building Control Conference 2012 | Athlone, 28-29
March 2012
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Energy in Buildings - Sustainability
• What is a sustainable solution?
• Sustainability – Embodied energy and embodied
carbon as indicators
• Why should embodied energy and embodied carbon
be considered?
• Material choice • Concrete and cements
• Steel
• Timber
• Case study
• Summary
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Energy in buildings – What is a
sustainable solution?
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Social
Economic Environmental
Bearable Equitable
Viable
Sustainable
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Sustainable construction Main impacts of construction industry and buildings (Sev 2008)
Sev, A. 2008 How can the construction industry contribute to sustainable development? A
conceptual framework. Sustainable Development 17 (2009) 161-173
Environ
-mental
Social Economic
Raw material extraction and construction, related resource
depletion
● ●
Land use change, including clearing of existing fauna ● ● ●
Energy use and associated emissions of greenhouse gases ● ●
Other indoor and outdoor emissions ● ●
Aesthetic degradation ●
Water use and waste water generation ● ●
Increased transport needs, depending on site ● ● ●
Waste generation ● ●
Opportunities for corruption ● ●
Disruption of communities, including through inappropriate
design and materials
● ●
Health risks on worksites and for building occupants ● ●
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Material choice
• Maximise • Minimise
Emissions
Waste
Fossil fuel use
Local impacts
Transport
Local employment
Fuel self-sufficiency
Resource recovery
Community benefits
Biodiversity
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Material usage
Total material use of the man-kind in 2005 F. Krausmann et al. / Ecological Economics 68 (2009) 2696–2705
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Structural Design
Lean design
Recycled materials
Renewable materials
Minimise waste
Design for long life
Holistic design
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Sustainability – Embodied energy and
embodied carbon as indicators
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What is embodied energy (EE) and embodied
carbon (EC)?
– Embodied energy (EE) is the energy
consumed over the duration of a
product’s life cycle
– Embodied carbon (EC) refers to the
CO2e consumed over the duration of a
product’s life cycle
– These refer to the energy and green
house gases required for the raw material
extraction, transportation, manufacture,
assembly, installation, disassembly,
deconstruction and/or decomposition for
any product or system.
– EE and EC are linked.
– Measure of sustainability
Carbon dioxide (CO2)
Methane (CH4)
Nitrous oxide (N2O)
Sulphur hexafluoride
(SF6)
HFCs
PFCs
CO2e
UNFCCC (1998). Kyoto protocol to the
United Nations framework convention on
climate change. http://unfccc.int/resource/docs/convkp/kpeng.pdf
1
25
298
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Life Cycle Profiles Cradle to Gate, Cradle to Site & Cradle to Grave
• Production stage (raw material supply, transport, manufacturing of
products, and all upstream processes from cradle to gate).
• Construction process stage (transport to the building site and wastage
from building installation/construction only) including transport and
disposal of waste.
• Use stage: repair, replacement, maintenance and refurbishment
including transport and disposal of waste over the life cycle study year
period.
• Demolition: is expected to occur any time at or after the end of the
study period and is included within its environmental profile. It includes
transport and disposal of waste.
• Recycling/reuse: to take account of all or part of the product that is recycled or
reused at the end of its life
Cradle
Gate
Site
Grave
Cradle
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EE and EC databases
• ICE database (http://people.bath.ac.uk/cj219/)
• GaBi database
• SIMAPRO
• Canadian Raw Material Database
• DEFRA – UK
• DIM1.0/ eVERdee
• Ecoinvent
• Boustead model
• worldsteel
* Many databases use process based analysis to determine intensities
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EE and EC databases
– ICE database (http://people.bath.ac.uk/cj219/)
Embodied energy (MJ/kg) Embodied carbon (kgCO2e/kg)
Tim
be
r
Tim
be
r
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Why should embodied energy and embodied
carbon be considered?
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– xx
Dixit M. K., Fernández-Solís J. L., Lavy S. and Culp C. H. (2010). "Identification of parameters for
embodied energy measurement: A literature review." Energy and Buildings 42(8): 1238-1247.
Life Cycle Energy of a Building
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Why is embodied energy (EE) and
embodied carbon (EC) important?
• The built environment is
responsible for 40% of European
energy consumption.
• The upcoming EPBD 2010 will
require all buildings to move
towards low energy standards.
• The EE/EC for a low energy
building’s total energy and carbon
over a full life cycle can be over
30% of the total consumed.
• Operational Energy vs. Embodied
Energy.
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.
Policy & influence
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Government white paper
• 25% increase in CO2 emissions in last 15 years
• 33% renewables by 2020
• 20% energy savings by 2020
• Green procurement
• We will revise and update existing social housing design guidelines to
ensure that all new capitally funded housing schemes are socially,
environmentally and economically sustainable, achieving energy efficiency
both at construction stage and during the lifetime of the scheme, e.g. by
climate sensitive design which takes account of the orientation,
Policy & influence
Energy efficiency
• Alternative energy systems
21. We are requiring developers of new buildings of
over 1,000m2 to investigate the feasibility of using
alternative energy systems.
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SEAI strategic plan
• Minimising environmental impacts of materials in
25 years
Policy & influence
Construction industry review
• Using renewable materials
• Using low-embodied energy materials •
Building regulations
• Minimum standards •
EU directives and commission documents
• 2002/91/EC
• 2003/87/EC
• 2007/589/EC •
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National Action Plan on Green Public Procurement (GPP) (Draft June 2011)
• The draft National Action Plan proposes seven priority product groups for which the public sector should seek to “green” their tendering processes on a national basis, including construction.
• Will provide a framework for the development of GPP in a consistent, progressive and coherent fashion.
• Will highlight existing best-practice procurement
• Will outline what further improvements can be made that would boost the percentage of GPP
Policy & influence
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30%
66%
4%
LCA Carbon (%) - Semi-Detached
Bungalows - B2 Rating Embodied Carbon
(KgCO2e)
Operational Carbon
(KgCO2e)
Reoccuring
Embodied Carbon
(KgCO2e)
LCA (Carbon) of Buildings – NUIG Case Studies
19%
77%
4%
LCA Carbon (%) - 2 Storey - B3
Rating Embodied Carbon
(KgCO2e)
Operational Carbon
(KgCO2e)
Reoccuring
Embodied Carbon
(KgCO2e)
21%
75%
4%
LCA Carbon (%) - Apartment Block
- C1 Rating Embodied Carbon
(KgCO2e)
Operational Carbon
(KgCO2e)
Reoccuring
Embodied Carbon
(KgCO2e)
The above examples show
the various contributions of
EC, RC and OC to each case
study building’s overall
carbon footprint.
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Sturgle Associates LLP Indicative Whole Life Carbon Emissions, RICS Research magazine, May 2010.
LCA (Carbon) of Buildings – other case studies
O’Loughlin, N. (2010), ‘Embodied CO2 of housing
construction in Ireland’, Architecture Ireland 247, pp70-71
A2 rated 3-bed
Semi-D A2 rated 2-bed
Apartment
Office Warehouse Supermarket House
Sturgle Associates LLP Indicative Whole Life Carbon Emissions, RICS Research magazine, May 2010.
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Jones (2011)
Future GHG in electricity generation?
Jones, C. (2011), ‘Embodied Carbon: A Look Forward
Sustain Insight Article: Volume I’, Sustain, Jan 2011
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Material choice
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• Material choice can be very influential in the carbon
footprint outcome of any building.
• A product may have a low Operational Carbon (OC)
and high Embodied Carbon (EC) but may be required
to be changed frequently
Material Choice
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LCA - Material Breakdown
Aggregate
Alluminium
Blocks Carpet
Concrete
Glass
Insulation
Lead
Mortar
Other
Paint
Plaster
Plastic
Sand
Slates
Steel
Tiles Timber
Vinyl Zinc
EC of Construction Materials (%)
Aggregate
Alluminium
Blocks
Carpet
Concrete
Glass
Insulation
Lead
Mortar
Other
Paint
Plaster
Plastic
Sand
Slates
Steel
Tiles
Timber
Vinyl
Semi-detached
Bungalows
Aggregate
Alluminium
Blocks Carpet
Concrete
Glass
Insulation
Lead
Mortar
Other
Paint
Plaster
Plastic
Sand
Slates
Steel
Tiles Timber
Vinyl
Zinc
EC of Construction Materials (%) Aggregate
Alluminium
Blocks
Carpet
Concrete
Glass
Insulation
Lead
Mortar
Other
Paint
Plaster
Plastic
Sand
Slates
Steel
Tiles
Timber
Vinyl
Zinc 2 Storey House
Sample case studies conducted by researchers at NUIG
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Concrete and cements
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Energy inputs to the concrete manufacturing
process (cradle to site)
•Concrete is the most widely used man made material by volume.
•It has an extremely energy intensive manufacturing process and
therefore, has high EE and EC.
.
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Cement production.
BES 6001
Environmental
& Alternative
fuels:
Chipped tyres
Meat and
bonemeal
Secondary
liquid fuel
SRF – solid
recovered fuel CMI (2011)‘The foundation of our nation’
3
1 1
12
13
10
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Cement production – energy flow.
Woodward R. (2011). Material and energy flow analysis of
the Irish construction sector. MSc thesis, CIT.
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Cement production.
Direct energy intensity for CEM I
cement in Ireland for 2005
Direct GHG (CO2e) emissions for
CEM I cement in Ireland for 2005
4.25MJ/kg 0.89kgCO2/kg McCaffrey M. (2011) ‘An I-O hybrid methodology for environmental LCA of embodied energy and
carbon in Irish products and services – A study of reinforced concrete’, MEngSc thesis, NUI
Galway.
49%
11%
19%
14%
58%
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Cement production – reduction in emissions.
CMI (2011)‘The foundation of our nation’
CMI member cement sales
Alternative fuel usage
0.75kgCO2/kg
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GGBS.
* This may change in future – burden sharing with steel industry?
*
0.79 0.072
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Clinker
NaturalNatural
calcinedSiliceous Calcareous
K S D b P Q V W T L LL
CEM IPortland
cementCEM I 95-100 - - - - - - - - - 0-5
CEM II/A-S 80-90 6-20 - - - - - - - - 0-5CEM II/B-S 65-79 21-35 - - - - - - - - 0-5
Portland-silica
fume cementCEM II/A-D 90-94 - 6-10 - - - - - - - 0-5
CEM II/A-P 80-94 - - 6-20 - - - - - - 0-5CEM II/B-P 65-79 - - 21-35 - - - - - - 0-5CEM II/A-Q 80-94 - - - 6-20 - - - - - 0-5CEM II/B-Q 65-79 - - - 21-35 - - - - - 0-5CEM II/A-V 80-94 - - - - 6-20 - - - - 0-5CEM II/B-V 65-79 - - - - 21-35 - - - - 0-5CEM II/A-W 80-94 - - - - - 6-20 - - - 0-5CEM II/B-W 65-79 - - - - - 21-35 - - - 0-5CEM II/A-T 80-94 - - - - - - 6-20 - - 0-5CEM II/B-T 65-79 - - - - - - 21-35 - - 0-5
CEM II/A-L 80-94 - - - - - - - 6-20 - 0-5CEM II/B-L 65-79 - - - - - - - 21- - 0-5CEM II/A-LL 80-94 - - - - - - - - 6-20 0-5CEM II/B-LL 65-79 - - - - - - - - 21- 0-5CEM II/A-M 80-94 0-5
CEM II/B-M 65-79 0-5
CEM III/A 35-64 36-65 - - - - - - - - 0-5CEM III/B 20-34 66-80 - - - - - - - - 0-5CEM III/C 5-19 81-95 - - - - - - - - 0-5CEM IV/A 65-89 - - - - 0-5CEM IV/B 45-64 - - - - 0-5
CEM V/A 40-64 18-30 - - - - - 0-5
CEM V/B 20-38 31-50 - - - - - 0-5
a) The values in the table refer to the sum of the main and minor additional constituents.b) The proportion of silica fume is limited to 10 %.
c) In Portland-composite cements CEM II/A-M and CEM II/B-M, in Pozzolanic cements CEM IV/A and CEM IV/B and in composite cements
CEM V/A and CEM V/B the main constituents other than clinker shall be declared by designation of the cement (For example see clause 8).
Blast-
furnace
slag
Silica
fume
Burnt
shale
CEM IV
CEM V
Pozzolanic
cement c
Composite
cement c
11-3536-55
18-30
31-50
6-20
21-35
Blastfurnace
cementCEM III
CEM II
Portland-slag
cement
Portland-
pozzolana
cement
Portland-fly ash
cement
Portland-burnt
shale cement
Portland-
limestone
cement
Portland-
composite
cement c
Main consituents
Composition (proportion by massa)
Notation of the 27 products
(types of common cement)
Main
typesMinor
additional
constituents
LimestoneFly ashPozzolans
Family of common cements EN 197-1.
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Clinke
Natu
ral
Natural
calcined
Silice
ous
Calcar
eous
K S D b P Q V W T L LL
CEM IPortland
cementCEM I 95-100 - - - - - - - - - 0-5
CEM II/A-V 80-94 - - - - 6-20 - - - - 0-5
CEM II/B-V 65-79 - - - - 21-35 - - - - 0-5
CEM II/A-W 80-94 - - - - - 6-20 - - - 0-5
CEM II/B-W 65-79 - - - - - 21-35 - - - 0-5
CEM II/A-L 80-94 - - - - - - - 6-20 - 0-5
CEM II/B-L 65-79 - - - - - - - 21-35 - 0-5
CEM II/A-LL 80-94 - - - - - - - - 6-20 0-5
CEM II/B-LL 65-79 - - - - - - - - 21-35 0-5
CEM III/A 35-64 36-65 - - - - - - - - 0-5
CEM III/B 20-34 66-80 - - - - - - - - 0-5
CEM III/C 5-19 81-95 - - - - - - - - 0-5
c) In Portland-composite cements CEM II/A-M and CEM II/B-M, in Pozzolanic cements CEM IV/A and CEM IV/B and in
composite cements CEM V/A and CEM V/B the main constituents other than clinker shall be declared by designation of the
a) The values in the table refer to the sum of the main and minor additional constituents.b) The proportion of silica fume is limited to 10 %.
CEM IIIBlastfurnace
cement
Limestone
CEM II
Portland-fly ash
cement
Portland-
limestone
cement
Main
types
Notation of the 27 products
(types of common cement)
Composition (proportion by massa)
Main consituents
Min
or
ad
dit
ion
al
co
ns
titu
en
t
Blast-
furnace
slag
Silica
fume
Pozzolans Fly ashBurnt
shale
Family of common cements EN 197-1.
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Cement production.
, CKD
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Cement production.
Source: CEMBUREAU 2008
EU cements types
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Steel
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Iron and Steel making flow chart • Ref: Worldsteel (2008) (75% of world production)
(25% of world
production)
(66%) (3%) (6%) (25%)
Energy Intensity
(GJ/t): 26.4 – 41.6 19.8 – 31.2 28.3 – 30.9 9.1 – 12.5
(*Energy associated with mining is excluded).
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Energy reduction in steel making
• Source: Worldsteel
Limit of current
technology?
Fe2O3 + 3CO -> 2Fe + 3CO2
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End-of life fate of materials
• 77% crushed
• Landfill avoided
• Primary aggregates
saved
• ‘Downcycling’
• 99% recycled or reused
• Landfill avoided
• Primary steel saved
• ‘True recycling’
• 16% recycled??
• 80% landfill??
• Decomposition CO2 CH4
• Landfill gas capture (51%)
Concrete Steel Timber
Ref: Sansom M. (2011)
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Recycling
• Content vs. Potential
• Why collection rate does make a difference
The water bottle example
Before drinking After drinking
Water 50 Cent
Bottle 50 Cent
Water 50 Cent
Bottle 50 Cent returned
Recycling Content
Cost = 50 Cent
Recycling Potential
Cost = 50 Cent
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Recycling
• Content vs. Potential
• Why collection rate does make a difference
The water bottle example
Before drinking After drinking
Water 50 Cent
Bottle 50 Cent
Water 50 Cent
Bottle 50 Cent lost
Recycling Content
Cost = 50 Cent
Recycling Potential
Cost = 100 Cent
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Databases
Different methods – UK Sections
Ref: Sansom M. (2011)
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Different methods
• PAS 2050 – Recycled content approach
• Allocates full recycling benefits to input side
• No consideration of the benefits of recyclability
• Worldsteel – Substitution approach (Closed loop system
expansion)
• Creation of recyclable material is allocated the full
benefit of recycling at end-of-life
• ISO compliant
• Bath ICE – 50:50 method
• Allocates half of the benefits of using recycled
materials at start of life and half of the benefits of
creating recycled materials at end of life
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Different methods
• Bath ICE – 50:50 method
• Approach represents a balance of:
• Accommodating the use of reused and recycled
materials and
• The design for reuse and recovery
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Timber
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Timber
Fertiliser
Pesticides
GHGs
Energy (sunlight) + H2O +
6CO2 → C6H12O6 + 6O2
Old forests release their stored
carbon slowly as they decay or
rapidly through wildfire Growing forests absorb carbon and release oxygen
Reforestation and
sustainable forest
management practices
ensure the carbon cycle
continues GHGs
CO2
GHGs
Sawmill (sawing,
planing, wood kiln
drying, transport)
Bioenergy is
produced from mill
and forest residues
Panel factory
(further
processing)
GHGs
GHGs
Wood products
store carbon Reuse
GHGs
GHGs
C6H12O6 + 6O2
→ 6CO2 + 6H2O
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Timber •Renewable source
•Carbon sequestration
•Different methods of forest management affect the affect
of carbon sequestration in trees*
•Requires minimum amount of energy-based processing
*Source: Perez-Garcia et al, 2005
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Timber
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Embodied energy of timber
•Note: These values were difficult to estimate because timber has a high
data variability.
•These values exclude the energy content of the wooden product (the
Calorific Value (CV) from burning).
*Source: ICE database
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Embodied carbon of timber
•Biogenic carbon storage and carbon sequestration are excluded from the
data.
•Data separates carbon dioxide emissions released from fossil fuels and
those from the burning of biomass fuel (i.e. timber off cuts).
*Source: ICE database
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Timber National Action Plan on Green Public Procurement (GPP)
(Draft June 2011) •Implement the FLEGT Action Plan in Ireland (by 2011)
•Establish a Due Diligence for operators placing timber products on the
market for the first time (commencing 2013)
•By 2017, it will be mandatory that construction timber will be procured
only from verified legally logged sources and from independently verified
sustainable sources.
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Material Choice – Case study
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Material Choice - Case study
• A 3-storey office block located in Galway city in Ireland
• RC Flat slab
– 5 x 5 grid
– 7m x 5m bay
– 30MPa concrete mix
– Reinforcement: 130kg/m3
• A comparison is made using two mix designs:
– Mix design 1: 100% OPC
– Mix design 2: 50% OPC + 50% GGBS
• Cradle-to-site
Goggins J., Keane T., Kelly A. (2010) ’The assessment of
embodied energy in typical reinforced concrete building structures
in Ireland’, Energy and Buildings 42 (2010) 735–744.
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Material Choice - Case study
Total 3,337GJ Total 2,705GJ
Mix design 1
(100% OPC)
Mix design 2
(50%OPC+50%GGBS)
Embodied Energy
Savings = 630GJ (i.e. 19%)
Equivalent to:
the energy used by 32.5 average homes in Ireland in one year
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Material Choice - Case study
Total 285,391kgCO2e Total 412,792kgCO2e
Mix design 1
(100% OPC)
Mix design 2
(50%OPC+50%GGBS)
Embodied Carbon
Savings = 127 tonnes (i.e. 31%)
Equivalent to:
41 cars off the road for one year
absorption of CO2 by 15.9 acres of managed Irish forest for one year.
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Summary
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Summary
• Sustainability – Environmental, Economic, Social
• Public sector will be required to “green” their tendering
process on a national basis, which includes construction
• Embodied energy and/or embodied carbon can be used
as indicators in sustainability assessment
• Operational energy vs. embodied energy and carbon
assessment
• Material choice – need technical understanding
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The benefits of carrying out an EE/EC
assessment
• Hot Spots in a product chain can be identified and
reduced;
• Stakeholders in any project will be able to make
informed decisions regarding the energy and carbon;
• Those decisions can then allow trade-offs between
cost analysis and carbon analysis to be made;
• Public awareness of energy intensive materials will
be highlighted thus allowing the actual sustainability of
products to be assessed;
• Companies developing sustainable products will be
able to highlight and market their products based on
energy and carbon savings.
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Thank you for your attention!
Dr. Jamie Goggins, National University of Ireland, Galway
“ We do not inherit the earth from our ancestors, we borrow it
from our children”