The Greening of the Rooftop

Why Roof Green?

Dr. James L. HoffResearch DirectorCenter for Environmental Innovation in RoofingWashington, DC

Why Roof Green?

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

Why Roof Green?

Increased Energy Efficiency

Renewable Energy Production

Cleaner Air & Water

Extended Building Life Cycle

Reduced Material Impacts

Why Roof Green?

… And Few Major Building Systems Are Installed as Frequently as Roofs

1 Billion Sq. Ft.

3 Billion Sq. Ft.

New Construction

Re-RoofingNorth 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!

Cool Roof Membranes Reduce Solar Loads

High “R” Insulation Reduces Energy Loss

Industry Best Practices Minimize Energy Waste

1

2

3

321

Multiple Ways to Save Energy

Why Roof Green?

Energy Efficiency

• 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

PresentR15

25%

25%

$306 Million

$119 Million

(-$13 Million)

(-$5 Million)

$407 Million

Green FutureR25

100%

100%

$192 Million

$71 Million

(-$30 Million)

(-12 Million)

$221 Million

$186 Million

Insulation R Value2

Cool Roof Usage3

Best Practice Usage4

Gross Heating Cost

Gross Cooling Cost

Cool Roof Adj.

Best Practice Adj.

Net Energy Cost1

Annual Savings

1Based 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.2Actual R values vary +/- R5, depending on ASHRAE climatic zone.3A cool roof is defined as a roof offering 50% long-term solar reflectivity or the thermal equivalent for the service life of the roof.4Best practice defined as 2 or more staggered insulation board layers to minimize thermal loss at board joints.

Why Roof Green?

Energy Scenarios

$152

$17

Cool RoofsBest 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

$1.8 Billion Annually$10+ Billion Cumulatively

Annual Energy Savings for 4 Billion Square Feet of Low-Slope Commercial Roofing Installations

(2008 Dollars)

$0$200$400$600$800

$1,000$1,200$1,400$1,600$1,800$2,000

1 2 3 4 5 6 7 8 9 10

Mill

ions

of

Dol

lars

Year

Increased Insulation

Cool RoofingBest Practice

The Green Future

Savings After Ten Years

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 Cost1

Total First Year Cost (4 Billion Sq. Ft.)

Incremental Cost

Net Annual Cost(2008 Dollars)

First Year Savings

20 Year Savings2

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 !

Why Roof Green?

Renewable Energy Production

Why Roof Green?

Renewable Energy Production

The Rooftops of the United States:

Segment:

Commercial (Flat)

Residential (Steep)

Total

Energy Potential2

Surface Area1

50 Billion Square Feet

150 Billion Square Feet

200 Billion Square Feet

50,000 Megawatts(10 Grand Coulie Dams)

1Derived from Census data2Assumes 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)

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%

Why Roof Green?

Other Environmental Benefits

Daylighting

Heat Island Reduction

Storm Water Retention

Extended Life Cycle Design Material

Recycling

Why Roof Green?

Increased Energy Efficiency

Renewable Energy Production

Cleaner Air & Water

Extended Building Life Cycle

Reduced Material Impacts