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The Greening of the Rooftop Module 5 Why Roof Green?

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Presentation on theme: "The Greening of the Rooftop Module 5 Why Roof Green?"— Presentation transcript:

1 The Greening of the Rooftop Module 5 Why Roof Green?

2 Few Major Building Systems Can Provide As Many Energy and Environmental Benefits …

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

4 Why Roof Green? … And Few Major Building Systems Are Being 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. … … exceeding new commercial construction by a factor of 4! Why Roof Green? The Roofing Multiplier Effect

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 –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)Annual energy costs based on 4 billion square feet roof installations, $0.12/KWH cooling energy cost, $1.00/therm heating energy cost, 2.0 cooling COP, and 75% heating efficiency. Assumes 20% of roofs are replacing existing cool roofs, 5% of roofs are installed over unheated spaces, and 20% of roofs are installed over non-cooled spaces. Calculations derived using the NRCA EnergyWise Calculator for gross heating and cooling costs and the DOE Cool Roof Calculator for cool roof energy savings. 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

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 1 Surface Area 75 Billion Square Feet 150 Billion Square Feet 225 Billion Square Feet 75,000 Megawatts (14 Grand Coulie Dams) 1 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 = 75,000 megawatts)

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

15 Why Roof Green? When It Comes To …. … We’re On Top Of It! Increased Energy Efficiency Renewable Energy Production Cleaner Air & Water Extended Building Life Cycle Reduced Material Impacts


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