The Role of LCA in Green BuildingDesign and Assessment:
Focusing on True EnvironmentalPerformance Measures
Wood Products Council and the Wood Solutions Fair is a Registered Providerwith The American Institute of Architects Continuing Education Systems. Creditearned on completion of this program will be reported to CES Records for AIAmembers. Certificates of Completion for non-AIA members are available onrequest.
This program is registered with the AIA/CES for continuing professionaleducation. As such, it does not include content that may be deemed orconstrued to be an approval or endorsement by the AIA of any material ofconstruction or any method or manner of handling, using, distributing, or dealingin any material or product. Questions related to specific materials, methods,and services will be addressed at the conclusion of this presentation.
Program Education Credit Information
Learning Objectives
• The why, what and how of Life CycleAssessment (LCA)
• The LCA toolkit• The integration of LCA in rating systems• The near term approach of assembly
assessment and ranking• The freely available EcoCalculator for
assemblies
Materials and resources creditsare especially weak in rating
systems . . .
. . . and very controversial
No! It’s aboutcertification! It’s all about
renewability!
Actually, you’re both wrong . . .
The use of wood is a good example
Materials selection is all about trade-offs!
CO2 neutral
Harvesting issues
Low energy
Abundant resources
Locally available
Recycled content
Water pollution
High CO2
Resistant to pests
regional
recycled content
rapidrenewability
durability
By attribute?
or...
Weighing material options
By environmental performance LCA
Resourcedepletion
Acid raindamage
Water pollution
Climatechange
Air pollution
Life CycleLife CycleAssessmentAssessment
transportationtransportationenergy useenergy use
emissions to airemissions to air emissions to wateremissions to water
solid wastessolid wastes
resourceresourceextractionextraction
effectseffects
resourceresourceuseuse
(depletion)(depletion)
water usewater use
A methodology for assessing the environmentalA methodology for assessing the environmentalperformance of a product over its full life cycleperformance of a product over its full life cycle
The ISO 14040 Framework
Life Cycle Assessment Framework
Goal & ScopeDefinition
InterpretationInventoryAnalysis
ImpactAssessment
Direct Applications
•Product Development& Improvement
•Strategic planning
•Public policy making
•Marketing
•Other
LCA in Relation toBuildings
Tracking Flows: The Inventory Step
BUILDING CONSTRUCTION(manufacturing)
OCCUPANCY(use, reuse, maintenance)
DEMOLITION/DISPOSAL
MATERIAL ACQUISITION
Manufacturing
Products / Assemblies
EnergyEnergy
WaterWater
MaterialMaterialresourcesresources
EmissionsEmissionsto:to:
AirAir
WaterWater
LandLand
Raw Material Acquisition
Waste Management
Recycle / Reuse
Products / Materials
Impact Assessment PhaseInventoryInventory
Impact Assessment Impact Assessment (Valuation)THE GOAL: to measure ultimate impactson human and ecosystem health
Impact IndicatorsImpact Indicators(characterization
& Normalization)
• fossil fuel depletion• global warming potential• ozone depletion• ground level ozone (smog)• acid rain• toxic releasesair/water/land• etc.
The rest of the story isthe energy to make andmove energy — calledpre-combustion in LCA
End use energyestimates just one
part of the story
Even sourceenergy doesn’t
get it all
In the Case of Energy…
LCA Limitations
LCA is not the answer to all problemsLCA is not the answer to all problems
E.g., does not readily handle such issues as:
Indoor environmental quality• Improved ability to deal with air quality possible in future
Uncertainty and risk related to toxic releases
Site specific resource extraction effects
The Uncertainty Factor
Occurs over aOccurs over arelatively shortrelatively short
time frametime frame(e.g 18-36(e.g 18-36months)months)
Is likely to lastIs likely to lastmany yearsmany years
(50 -100 or more)(50 -100 or more)
BUILDING CONSTRUCTION(manufacturing)
OCCUPANCY(use, reuse, maintenance)
DEMOLITION/DISPOSAL
Waste Management
Recycle / Reuse
Products / Materials
MATERIAL ACQUISITION
Raw Material Acquisition
Manufacturing
Products / Assemblies
Focus on relative effects,not absolute numbers!
Life Cycle Assessment is not the same asLife Cycle Costing!
LCA physical units
LCC $Complementarymethods
The LCA toolkitLevel 1 — product focus
1A - for LCA practitioners
SimaPro, GaBi, Umberto
1B - LCA in the background
BEES
Level 2 — assembly focusATHENA® EcoCalculator
funded by GBI for use in GreenGlobes rating system
general use versions coming
Level 3 — whole buildingfocus
ATHENA® Impact Estimator
LCA in the background
Assessment and ratingsystem
Green Globes LEED Minnesota Design Guidelines NAHB Green Home Guidelines
BEES Model (U.S.)
• Focuses on environmental effects and life cycle costs• Provides detailed results for a wide range of impact
indicators• Uses weighting factors to generate environmental and
economic scores• Based on Consensus Standards
LCA-based Level 1 product comparison toolfor use at the specification/procurement stage
BEES 3 Impact Measures
Smog
Global Warming Acidification
Eutrophication Fossil Fuel Depletion
Indoor Air Quality Habitat Alteration
Overall Score
First Cost Future Costs
Carbon Dioxide
Methane
Nitrous Oxide
Ozone Depletion Ecological Toxicity
Human Health
Water Intake Criteria Air Pollutants
Environmental Performance
Score
Economic Performance
Score
LCA-based level 3 whole building tool for use at theconceptual design stage
Shows environmental effects of changes in shape,design or material make-up of a building
Allows designers to optimize operating+embodiedenergy effects over the complete building life cycle
A range of indicators without weighting
Impact Estimator for Buildings
Design 1 Design 2Regional
Electricity GridsTransportation & Product Technologies
Maintenance Schedules Raw Materials Energy Use by type Water Use Emissions to Air Emission to Water Solid Wastes
INVENTORY
Energy Use Global Warming Potential Air Pollution Water Pollution Resource Extraction Effects Solid wastes
SUMMARY MEASURES
BuildingAssemblies
Bill of Materials
Life Cycle InventoriesMaterials & Products
Building ConstructionOperations
Demolition/ Disposal
Energy pre-combustion
effects
. . . informed environmental choices
Picking the Right Tool
Functional equivalence . . .• Want to compare functionally equivalent
products• Choice of one product other choices• Differences in O & M implications• Misleading comparisons more likely for
structure and envelope products
. . . be cautious about product comparisons
BEES
The right data and tool for the task
Generic atconceptual design
Brand specific atprocurement stage
ImpactEstimator
forBuildings
LCA in Assessment, Rating Systemsand Standards
Green Building Standards• GBI/ANSI Standard 01-2007P: Green Building
Assessment Protocol for Commercial Buildings
• ASTM: Standard Specification for the MinimumAttributes of a Building that PromotesSustainability
• NAHB: National Green Building StandardTM
• ASHRAE/USGBC/IESNA Std 189: High-Performance Green Buildings
Could progress over time, from short to long term ideal approach
Option 1pre-rate assemblies
LCA in background
limited demands ondesign teams
more demands on therating organization
focus on materials
simplistic
Option 2decisions based on LCA
design teams may usewhole building LCA tool(s)
could combine embodiedand operations effects
difficult to verify
high educational value
Option 3whole building LCA
high demands on designteams
need benchmarks (onuson rating system orgs.)
combine embodied andoperations effects
supports optimization ofenvelope vs. operations
Options for LCA into rating systems
LCA in Green Globes• LCA education credits at present• Work completed on the assembly ranking approach• Points based on performance relative to benchmarks• Will be included in ANS version of Green Globes
– after public comment and ANSI procedures complete
• Basic tool reviewed by the Building ResearchEstablishment (UK), NIST and others
• Assembly definitions reviewed and refined by the ANSIresources sub-committee
LCA into LEED (US)
• September 2004 kick-off meeting• Working Groups
• goal and scope• technical LCA issues• weighting of impact measures
• Goal and scope WG recommended assemblyranking approach
• Initial focus on MR credits• Accepted by USGBC board• Decision made to start with the EcoCalculator
– research program to detail the approach
Whole House Residential Case Study
Covers embodied effects from resource extractionthrough on-site construction
Results Overview
%
23% difference
Wood-Framed House Componentsby Mass
Concrete 63%
Sheetrock 5%
Insulation 5%
Roofing 5%
Siding 2%
Wood 17%Metal 3%
Although referred to as awood-framed house, concreteis the dominant mass, withother materials playing lesserroles by mass.
If we go to theIf we go to theassembly levelassembly level
Exterior Wall AssembliesRelative GWP
170% difference
New Tool for use inNew Tool for use inRating SystemsRating Systems
Makes such information moreMakes such information moreaccessible to design teamsaccessible to design teams
Impact Estimatorfor buildings
EcoCalculatorfor buildings
LCA-based tool for evaluating and comparingthe environmental effects of assemblies
Currently includes several hundred assemblies Uses 5 environmental impact indicators Regionalized, with more regions under development In rating system, credit better than average performance
for each indicator within an assembly category Generic version, without credit links, is freely available
EcoCalculator for assemblies
Simple to Use
Users only fillin yellow cells
Instant answers
results in spreadsheet form
Wood I-joist and OSB decking system,gypsum board, latex paint
9 tons CO2ecradle to grave
60 year life
EcoCalculatorfor assemblies
3/31/08 42
Key Assumptions• Results on a per unit area basis (e.g., per ft2)
– Estimates based on much larger areas, e.g., 1000 linear feet ofwall
• Owner occupied buildings, 60-year lifespan– Affects maintenance and repair/replacement schedules
• Other specific assumptions:– Window to wall ratio– Concrete strength and fly ash content– Gypsum board type and thickness– Live load for all intermediate floors, columns & beams, roofs– Bay sizes and column heights– External wall thicknesses depending on construction system– Stud size/strength and spacing– Sheathing and decking materials
3/31/08 43
EcoCalculator Versions• Current
– Northern USA averages– Southern USA averages– 8 Canadian regions
• Vancouver, Calgary, Winnipeg, Toronto, Ottawa, Montreal,Québec, Halifax
– 4 US regions• Atlanta, Minneapolis, Orlando, Pittsburgh
• Coming– Los Angeles, New York, Seattle, Phoenix, Denver, +
All with hi-rise and low-rise versions
In Conclusion: LCA tools let you ... Take the environment into account throughout the
project delivery process Focus on true environmental performance measures Look at the entire life cycle of a building Make functionally equivalent material comparisons Recognize and take account of environmental and
economic trade-offs
A FINAL CAUTION:A FINAL CAUTION:BE WARY OF SIMPLISTIC ANSWERSBE WARY OF SIMPLISTIC ANSWERS
TO COMPLEX QUESTIONSTO COMPLEX QUESTIONS
Questions/ Comments?This concludes the:
• American Institute of Architects
Continuing Education Systems Program
www.athenaSMI.ca