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The Greening of the Rooftop Why Roof Green? Dr. James L. Hoff Research Director Center for Environmental Innovation in Roofing Washington, DC.

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Presentation on theme: "The Greening of the Rooftop Why Roof Green? Dr. James L. Hoff Research Director Center for Environmental Innovation in Roofing Washington, DC."— Presentation transcript:

1 The Greening of the Rooftop Why Roof Green? Dr. James L. Hoff Research Director Center for Environmental Innovation in Roofing Washington, DC

2 Why Roof Green? Few Major Building Systems Can Provide As Many Energy & Environmental Benefits …

3 Why Roof Green? Increased Energy Efficiency Renewable Energy Production Cleaner Air & Water Extended Building Life Cycle Reduced Material Impacts

4 Why Roof Green? … And Few Major Building Systems Are Installed as Frequently as Roofs

5 1 Billion Sq. Ft. 3 Billion Sq. Ft. New Construction Re-Roofing North American Low-Slope Roofing Market (Billions of Square Feet, 2006) Source: Roofing Industry Consensus Data Each year, 4 billion square feet of commercial roofs are installed in the U.S. … Why Roof Green? … exceeding new commercial construction by a factor of 4!

6 Cool Roof Membranes Reduce Solar Loads High “R” Insulation Reduces Energy Loss Industry Best Practices Minimize Energy Waste 1 2 3 3 21 Multiple Ways to Save Energy Why Roof Green? Energy Efficiency

7 The Present (At best) –ASHRAE 90.1-1999 –“Energy Standard for Buildings…” –Basic roofing “R” values unchanged since 1973 A Greener Future (What we can do) –ASHRAE 189.P (Proposed) “Standard for the Design of High-Performance Green Buildings…”” –67% average increase in minimum roof “R” values Why Roof Green? Energy Scenarios

8 Present R15 25% $306 Million $119 Million (-$13 Million) (-$5 Million) $407 Million Green Future R25 100% $192 Million $71 Million (-$30 Million) (-12 Million) $221 Million $186 Million Insulation R Value 2 Cool Roof Usage 3 Best Practice Usage 4 Gross Heating Cost Gross Cooling Cost Cool Roof Adj. Best Practice Adj. Net Energy Cost 1 Annual Savings 1 Based on 4 billion square feet roof installations, assuming $0.12/KWH cooling energy cost, $1.00/therm heating energy cost, 2.0 cooling COP, and 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. Calculations derived using the NRCA EnergyWise Calculator and DOE Cool Roof Calculator. 2 Actual R values vary +/- R5, depending on ASHRAE climatic zone. 3 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. 4 Best practice defined as 2 or more staggered insulation board layers to minimize thermal loss at board joints. Why Roof Green? Energy Scenarios

9 $152 $17 Cool Roofs Best Practice First Year Energy Savings: 4 Billion Sq. Ft. of Low-Slope Commercial Roofing Installations (Millions of 2008 Dollars) The Green Future First Year Savings $7 Increased Insulation Total: $186 Million

10 $1.8 Billion Annually $10+ Billion Cumulatively Annual Energy Savings for 4 Billion Square Feet of Low-Slope Commercial Roofing Installations (2008 Dollars) Millions of Dollars Year Increased Insulation Cool Roofing Best Practice The Green Future Savings After Ten Years

11 Present $5.00 / Sq. Ft. $20 Billion $407 Million Green Future $5.65 / Sq. Ft. $22.6 Billion $2.6 Billion $221 Million $186 Million $6.8 Billion 13.1% Unit Installed Cost 1 Total First Year Cost (4 Billion Sq. Ft.) Incremental Cost Net Annual Cost (2008 Dollars) First Year Savings 20 Year Savings 2 Average Annual ROI (1) Cost data provided from survey conducted by TEGNOS Research, Inc. (2) Assumes energy costs will increase 6% annually above non-energy core inflation rate The Green Future Economic Return … plus potential tax deductions under the 2008 Energy Tax Incentives Act !

12 Why Roof Green? Renewable Energy Production

13 Why Roof Green? Renewable Energy Production The Rooftops of the United States: Segment: Commercial (Flat) Residential (Steep) Total Energy Potential 2 Surface Area 1 50 Billion Square Feet 150 Billion Square Feet 200 Billion Square Feet 50,000 Megawatts (10 Grand Coulie Dams) 1 Derived from Census data 2 Assumes 1watt 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 1 watt / square foot)

14 Will Demand for Solar Homes Pick Up? Builders find the savings from cheap power is making solar homes more attractive November 3, 2008 By Adam Aston As global financial markets melted down in October, Congress handed a gift to America's green energy industry: It renewed and broadened a set of tax credits for wind and solar power, geothermal, tidal energy, and more. The move did little to prop up eco- energy stocks, which have followed oil prices down. But the news did send a positive jolt to one of the economy's darkest sectors: homebuilding. Or, more specifically, solar-powered homes. Consumers recognize that green homes "save money month in, month out," says Rick Estimated minimum pretax annual rate of return for a residential solar system in California and many other states, starting in 2009. Why Roof Green? Renewable Energy Production 15%

15 Why Roof Green? Other Environmental Benefits Daylighting Heat Island Reduction Storm Water Retention Extended Life Cycle Design Material Recycling

16 Why Roof Green? Increased Energy Efficiency Renewable Energy Production Cleaner Air & Water Extended Building Life Cycle Reduced Material Impacts


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