How Green is Green?
Measuring Sustainability
with Life Cycle Assessment
(LCA)
James L. Hoff, DBA
Research Director
Center for Environmental
Innovation in Roofing
Learning Objectives
1.
2.
3.
4.
Understand current definitions of sustainability as they
relate to buildings and the building envelope.
Understand the relationship between sustainable building
design and the use of Life Cycle Assessment (LCA) to
measure and document sustainability.
Identify the basic steps in the LCA process, the way LCAs are
communicated, and the resources currently available to
conduct LCA.
Understand the current status of LCA as it relates to
sustainable building standards and rating systems such as
LEED and Green Globes.
Agenda
• Background
– What is Sustainable?
– Why Sustainable Roofing?
• Measuring Sustainability with LCA
– What is LCA?
– LCA Tools
– LCA and Roofing
Sustainable
“...meeting the needs of the present
without compromising the ability of
future generations to meet their own
needs."
The Brundtland Commission (1)
(1) UN World Commission on Environment and
Development, “Our Common Future,” April 1987.
Sustainable
Sustainable
Why Sustainable Roofing?
Few Major Building Systems Offer As
Many Energy & Environmental Benefits…
… And Few Major Building Systems Are
Installed as Frequently as Roofs!
Sustainable Roofing Benefits
 Increased Energy Efficiency
 Reduced Global Warming
 Cleaner Air & Water
 Reduced Material Waste
 Extended Building Life Cycle
 Renewable Energy & Food Production
 Increased Health & Well-Being
The Roofing Multiplier Effect:
1 Billion
Sq. Ft.
3 Billion
Sq. Ft.
Re-Roofing
New Construction
North American Low-Slope
Roofing Market
(Billions of Square Feet, 2006)
Each year, 4 billion square feet of commercial roofs are installed in
North America, exceeding new commercial construction by 4 to1!
Source: TEGNOS Research, Inc. 2008
Sustainable Roofing
The Energy Efficiency Dividend
$2,000
$1,800
$1,600
$1,400
$1,200
$1,000
$800
$600
$400
$200
$0
$1.8 Billion Annual Savings
$10+ Billion Cumulative Savings
After 10 Years
Increased
Insulation
Cool Roofing
Best Practice
1
2
3
4
5
6
7
8
9
10
Potential Energy Savings
(2008 Dollars / 4 Billion Sq. Ft. per Year Installed)
Source: Center for Environmental Innovation in Roofing. Based on 4 billion square feet roof installations, assuming $0.12/KWH cooling cost, $1.00/therm heating cost, 2.0 cooling COP, 75% heating efficiency, 20% of
roofs replace existing cool roofs, 5% of roofs installed over unheated spaces, and 20% of roofs installed over non-cooled spaces. Increased insulation compares the suggested roof insulation R values of ASHARE 189.P
against current typical state energy code practice (ASHRAE 90.1 – pre 2007). A cool roof is defined as a roof offering 50% long-term solar reflectivity or the thermal equivalent for the service life of the roof. Best
Sustainable Roofing
The Clean Energy Dividend
Roofing Segment:
Surface Area1
Commercial (Flat)
50 Billion Square Feet
Residential (Steep)
150 Billion Square Feet
Total U.S. Rooftops
200 Billion Square Feet
Energy Potential2
500,000 Megawatts
(100 Grand Coulie Dams)
1Derived
from Census data
10 watt average solar power production during daylight hours per square foot of suitable roof surface (225 billion square
feet total roof surface X 25% suitable usage factor X 10 watts / sq. ft.)
2Assumes
Life Cycle Assessment
What is LCA?
… a scientific approach to
evaluating the environmental
impact of a product
throughout its life cycle.
Life Cycle Assessment
What is LCA?
– Scientific Approach: Based on measurable and
predictable attributes
– Focused on Impact: What is the net result to the
environment?
– Throughout the Life Cycle: A “cradle-to-grave”… or
“cradle-to-cradle” approach
Life Cycle Assessment
Why is LCA Important?
• LCA is a globally recognized procedure based on
established ISO standards
• LCA will be incorporated into the LEED® Green
Building Rating System in 2010 / 2011
• LCA is a necessary measure to support emerging
global warming initiatives such as carbon cap-andtrade
Life Cycle Assessment
Key LCA Steps
1. Establish the Time Period
2. Describe the Life Cycle System
3. Identify & Measure the Impacts
4. Assess the Impacts
LCA Step 1:
Establish the Time Period
Typical
Commercial Roof Warranty
Length
10 Years
15 Years
20 Years
U.S. Taxable Building
Depreciation Period
USGBC Life Cycle
Task Force
Recommendation
30 Years
39 ½ Years
60 Years
LCA Step 2:
Describe the Life Cycle System
Inputs:
Raw
Materials
Energy
Processes:
Raw Materials Acquisition
Atmospheric
Emissions
Manufacturing
Waterborne
Waste
Transportation & Handling
System
Boundary
Outputs:
Installation / Assembly
Solid Waste
Co-Products
Other Releases
Operation / Maintenance
Recycling / Waste Mgmt.
Source: Life Cycle Assessment: Principles and Practice. Scientific Applications International Corporation, 2006.
LCA Step 3:
Measure the Impacts
The TRACI Impact Model
Impact:
Global Warming Potential
Ozone Depletion Potential
Photochemical Oxidant Potential
Acidification Potential
Eutrification
Health Toxicity (Cancer)
Health Toxicity (Non-Cancer)
Health Toxicity (Air Pollutants)
Eco-Toxicity Potential
Linked To:
Global Climate Change
Degradation of Ozone Layer
Ground-Level Ozone
Acid Rain
Algae Blooms
Cancer Frequency
Neurological / Reproductive Disorders
Breathing-Related Illnesses
Reproductive / Genetic Disorders
LCA Step 3:
Measure the Impacts
The TRACI Impact Model
Impact:
Global Warming Potential (GWP)
Ozone Depletion Potential (ODP)
Photochemical Oxidant Potential
Acidification Potential
Eutrification
Health Toxicity (Cancer)
Health Toxicity (Non-Cancer)
Health Toxicity (Air Pollutants)
Eco-Toxicity Potential
Standard Measure:
kg CO2 Equivalent
kg CFC Equivalent
kg NOX Equivalent
H+ Moles Equivalent
kg Nitrogen Equivalent
kg Benzene Equivalent
kg Toluene Equivalent
kg DALYs Equivalent
kg 2,4-D Equivalent
LCA Step 4:
Assess the Impacts
• Weigh the Impacts
– Which impacts are most important in the assessment?
• Compare Alternatives
– Which alternative provides the optimal benefit?
• Look for Improvement Opportunities
– How can the impacts be reduced?
Life Cycle Assessment
LCA Benefits
• Avoids Shifting of Impacts
• Allows Consideration of Trade-Offs
• Promotes Situation-Based Decisions
Life Cycle Assessment
LCA Limitations
•
LCA is Expensive
–
•
Requires time & money
LCA is Complex
–
•
Difficult to understand & communicate
LCA is Not Absolute
–
–
Useful for reference or comparison
Cannot by itself determine cost-effectiveness or practicality
Life Cycle Assessment
LCA Standards
Part of ISO 14000
–
“Standard for Environmental Management”
–
Similar to ISO 9000 “Standard for Quality Management”
–
Describes how LCA should be used to evaluate products
and how the results should be communicated to the
consumer
Life Cycle Assessment
Communicating LCA Data
Environmental Product Declaration (EPD)
–
ISO 14000 method for communicating to the consumer
–
Growing rapidly in Europe
–
Driven by global corporations seeking common
denominator to simplify product lines
Environmental Product Declaration
Sample EPD
Product:
Polystyrene Board
Manufacturer:
LAPE (Italy)
Environmental Product Declaration
EPD Detail
Life Cycle Diagram:
System Boundary
(In this case, excludes installation, use
and final disposal)
Impact Summary:
Impact
Category
Impact
Measure
Impact
Data
Environmental Product Declaration
Sample EPD
Product:
Steel Roofing System
Manufacturer:
Corus (UK)
Environmental Product Declaration
EPD Detail
Life Cycle Diagram:
Impact Summary:
System Boundary
Impact
Category
(In this case, covers “cradle-to-grave”)
Impact
Measure
Impact
Data
Environmental Product Declaration
EPDs Moving to United States
Product:
Office Chair
Manufacturer:
Steelcase (USA)
Life Cycle Assessment
LCA Tools
EPD
EPD
EPD
EPD
EPD
EPD
LCI Database
Project Requirements
Environmental Product
Declaration (EPD)
Life Cycle Inventory (LCI)
Life Cycle Assumptions
LCA Tool
Local Conditions
Impact Weighting
Project Life Cycle Assessment
Life Cycle Assessment
LCA Tools
•
•
•
•
Web-based or downloaded programs
Sponsored by government or non-profit organizations
Generally follow a recognized LCA protocol
Draw from life cycle inventory (LCI) databases for
impact information
• Combine products and processes to evaluate whole
buildings or major sub-systems
Life Cycle Assessment
LCA Tools
Tool:
Sponsor:
Cost:
Athena Institute
(Canada)
Free Download
$1,000 +/NIST (USA)
Free Download
Univ. of Stuttgart
(Europe)
Free Download
LCA Tools
Athena EcoCalculator
Summarizes
Key Impacts
Select from
nearly 100
roof/deck
assemblies
Different
spreadsheets for
different climates
Simply enter
roof surface area
Free Download Available:
http://www.athenasmi.org/tools/ecoCalculator/index.html
Athena EcoCalculator
Limitations
• Not all product data has been peer-reviewed
and validated
– Some databases may contain significant product
formulation errors
– Database errors may influence overall assessment validity
• Most of the product data is generic, based on
a composite of different proprietary products
– Database may not reflect real differences between
different proprietary products and processes
LCA Tools
BEES 4.0
• Building for Environmental & Economic Sustainability
• Maintained by National Institute of Science &
Technology (NIST)
• Free download available
• Peer-reviewed and validated
• Limited, but growing product database
Free Download Available:
http://www.bfrl.nist.gov/oae/software/bees/bees.html
BEES 4.0
Comprehensive Model
Uses Validated &
Weighted Averages
Provides Overall
Weighted Score
Key Impacts
Considers Economic
as well as
Environmental
Factors
BEES 4.0
Validated & Weighted Scoring System
Key Impacts
Peer-Reviewed &
Validated Weighted Average
Alternative A
Simple Graphic Report
Alternative B
BEES 4.0
Limited Product Database
… but peerreviewed,
validated, and
growing
LCA Tools
In the Future …
• US Life Cycle Inventory Database (US LCI)
– Joint Athena Foundation / US Government Initiative
– Funded in part by EPA, GSA, and DOE
– Managed by National Renewable Energy Laboratory
(NREL)
– Establishing peer-review & validation guidelines
– Slowly, but surely expanding the database
LCA Tools
US LCI
US Life Cycle Inventory Database
NREL and its partners created the U.S. Life-Cycle Inventory (LCI) Database to help life-cycle assessment (LCA) experts answer their questions about
environmental impact. This database provides a cradle-to-grave accounting of the energy and material flows into and out of the environment that are
associated with producing a material, component, or assembly. It's an online storeroom of data collected on commonly used materials, products, and
processes.
http://www.nrel.gov/lci
Life Cycle Assessment
The Future of LCA
• ISO 14000 will become the global LCA model
– ISO 14000 has been accepted worldwide as the model for managing
environmental impacts
– Almost all global companies have obtained ISO 14000 registration for
their facilities – and this will carry over to their products
• Use of LCA tools will become standard for all
major construction projects
– Integration of LCA tools into LEED will accelerate the process
• EPD will be the “New MSDS”
– Specifiers may soon require EPDs or similar data for all products
LCA and the Roofing Industry
Short Term Impact
• Confusion Will Reign
–
–
ISO 140OO is a standard approach – not a standard
Standard ground rules have not yet been written
–
Competing standards and rating systems will only add to the
confusion
• Early Adapters Will Establish the Rules
–
Defining system boundaries (Category Rules)
–
Establishing weighting protocols
LCA and the Roofing Industry
Long Term Impact
• LCA will favor thinner, stronger products
–
Lightweight membranes and coatings
–
Lightweight foam insulations
• LCA will favor systems that can be installed,
repaired, removed & recycled quickly
–
New attachment technologies
–
Increased emphasis on planned maintenance & repair
–
Industry recycling programs
Life Cycle Assessment
Critical Issues
• Where to set system boundaries:
• After manufacture? After installation?
• During use – including maintenance and/or renewal?
• At end of life – including disposal and/or recycling?
• How to define & weight impacts:
• Energy: Energy to produce and install? Energy saved during use? Energy
produced during use?
• Global Warming: Offsets beyond energy, e.g. potential global warming
offset from reflective surfaces?
• How to define service life:
• Same for all products assessed?
• Include planned maintenance and renewal?
Center for Environmental
Innovation in Roofing
816 Connecticut Ave, NW
Washington, DC 20006
www. roofingcenter.org