1. Athena’s EcoCalculator
For Assemblies
Jamie Meil
Toronto Green Building Festival
October, 2007
2. Resource Use Focus:
It’s All About Trade-offs!
Abundant resources
High CO2
Resistant to pests
Locally available
CO2 neutral
Water pollution
Recycled content Low energy
Harvesting issues
3. Weighing material options
By attribute?
short-term
renewability
regional
durability
recycled content
or...
4. By environmental performance LCA
Air pollution
Acid rain
damage
Climate
change
Resource
depletion Water pollution
5. transportation
water use energy use
resource Life Cycle resource
use extraction
(depletion) Assessment effects
emissions to air emissions to water
solid wastes
A methodology for assessing the environmental
performance of a product over its full life cycle
7. Tracking Flows: The Inventory Step
MATERIAL ACQUISITION
Raw Material Acquisition
Manufacturing
Material Emissions
Products / Assemblies to:
resources
BUILDING CONSTRUCTION Air
(manufacturing)
Energy
OCCUPANCY
(use, reuse, maintenance) Water
DEMOLITION/DISPOSAL Land
Water
Products / Materials
Recycle / Reuse
Waste Management
8. Impact Assessment Phase
Inventory • fossil fuel depletion
• global warming potential
•(characterization
ozone depletion
Impact Indicators • ground& level ozone (smog)
Normalization)
• acid rain
• toxic releasesair/water/land
• etc.
Impact Assessment (Valuation)
THE GOAL: to measure ultimate impacts
on human and ecosystem health
9. LCA-Based whole building tool for use at the
conceptual design stage
Shows environmental effects of changes in shape,
design or material make-up of a building
Allows designers to optimize operating+embodied
energy effects over the complete building life cycle
A range of indicators without weighting
10. Takes Account Of
Resource extraction
Manufacturing and on-site construction
Including recycled content
All related transportation
Maintenance and replacement cycles
Demolition and land filling
Operating energy effects
All but the last included in assembly calculations
11. Residential EE History
Home Type, Heating Energy Embodied EE in years of
Location Gj/yr Energy GJ Heating Energy
Conventional, 107 1000 9.4
Vancouver
Energy Efficient, 60 1075 17.9
Vancouver
Conventional, 136 1000 7
Toronto
Energy Efficient, 82 1075 13.1
Toronto
Cole, R (1994)
12. Embodied vs. Operating Energy - Australia
7000
6000
5000
Cumulative GJ
4000
3000
2000
1000
0
0 10 20 30 40 50 60 70 80 90 100
Years
High Operating Normal Operating
Low Operating Embodied
13. Significance of Embodied Material Effects
Building a single family house embodies
10-20 yrs of operating energy use
2006 Cdn housing starts - 225,000 units
» Therefore, these starts are equivalent to
2-4 million operating energy yrs
Cdn Housing stock - 12 million units
» So a year’s worth of building is
equivalent to 15-30% of all residential
operating energy use
Excludes residential renovation market
material use
» Similar in market size to new residential
construction
Embodied effects of material use may
be equivalent to 50% of all residential
annual energy use
15. LCA integration options
Award points for:
1. Selecting highly ranked building assemblies
from a pre-rated list
2. Making decisions based on the use of an
LCA tool (e.g., education or innovation credits)
3. Achieving specific performance levels at the
whole building level (e.g., 2030 Challenge)
16. LCA in Green Globes
Basically LCA education credits at present (option 2)
» encourage selecting materials with the lowest life cycle
environmental burden
» but no firm benchmarks or measures
Work completed on the assembly ranking approach
(option 1)
» reviewed by BRE, NIST, 3rd party
» under review by Green Globes ANSI committee,
» ATHENA Impact Estimator for buildings used for basic LCA
of assemblies
» points based on performance relative to benchmarks for
each of several measures (e.g., global warming potential)
17. LCA into LEED
September 2004 kick-off meeting
Working Groups
» recommend how best to implement LCA-based credits
• goal and scope
• technical LCA issues
• weighting of impact measures
Goal and scope WG recommended assembly
ranking approach
Accepted by USGBC board
Research program underway to detail the approach
18. New Tool for use in
Rating Systems
Makes such information more
accessible to design teams
19.
20. LCA-based tool for evaluating and comparing the
environmental effects of assemblies
Currently includes about 400 assemblies
Uses 5 environmental impact indicators
In rating system, credit better than average performance
for each indicator within an assembly category
Generic version, without credit links, is freely available
various regional versions under development
21. Key Assumptions
Results on a per unit area basis (e.g., per ft2)
Estimates based on much larger areas, e.g., 1000 linear feet of wall
Components and loadings typical for central U.S.
Owner occupied office 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 with latex paint
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
22. What’s in and out?
LCA of building assemblies takes account of:
» resource extraction and processing
» product manufacturing
» on-site construction of assemblies
» all related transportation
» maintenance and replacement cycles over an assumed building
service life
» demolition and end-of-life disposition of materials
Operating energy effects covered in rating systems
23. Simple to Use
results in spreadsheet form
Users only fill
in yellow cells
Instant answers
25. EcoCalculator Versions
Current Coming in 2008/09
Northern USA Minneapolis region
» High-Rise Atlanta
» Low-Rise Pittsburgh
Southern USA New York
» High-Rise Los Angeles
» Low-Rise
Seattle
Vancouver Other Canadian regions
