- What is a cool roof?
- What kind of roofing products are available for commercial and residential applications?
- How cool is a cool roof?
- Do cool roofs cost more than conventional roofs?
- Are rebates available for cool roofs?
- Where do I find cool roofs in California's Title 24 Building Energy Efficiency Standards?
- Are cool roofs required in the residential or nonresidential energy standards?
- What specifications does a roof need to meet to be considered for credit under the Title 24 Standards?
- When does the Cool Roof Rating Council become the supervisory entity for cool roofs in California?
What is a cool roof?
Cool roofs are highly reflective and emissive materials that stay 50 to 60 degrees F cooler in the summer sun, thereby reducing energy costs, improving occupant comfort, cutting maintenance costs, increasing the life cycle of the roof, and contributing to the reduction of urban heat islands and associated smog.
What kind of roofing products are available for commercial and residential applications?
Products for low-slope roofs, found on commercial and industrial buildings, fall into two categories - single-ply materials and coatings. Single-ply materials are large sheets of pre-made roofing that are mechanically fastened over the existing roof and sealed at the Seams. Coatings are applied using rollers, sprays, or brushes, over an existing clean, leak-free roof surface.
Products for sloped roofs, usually found on residences, are currently available in clay, or concrete tiles. These products stay cooler by the use of special pigments that reflect the sun's infrared heat. Lower priced shingles or coated metal roofing products are not yet available in "cool" versions.
Visit the ENERGY STAR® Website for a list of cool roof products and manufacturers. www.energystar.gov
How cool is a cool roof?
During the summer, a typical dark roof is 150 to 190 degrees Fahrenheit at peak, while cool roofs peak at 100 to 120 degrees Fahrenheit.
Do cool roofs cost more than conventional roofs?
Initial material costs are comparable with traditional roofing materials - some cool products cost less than traditional materials, some cost up to 20% more. Cool protective coatings can be reapplied repeatedly every 10 to 15 years and reduce, if not eliminate the need for expensive roof tear-offs. Combining these maintenance savings with an average 20 percent savings on air conditioning costs make cool roofing a better bargain over the long term.
Are rebates available for cool roofs?
In addition to energy and life cycle savings, rebates are available from some local utility companies for cool roofing in California. For more information on cool roof rebates, visit the Flex Your Power website at: www.fypower.org
Where do I find cool roofs in California's Title 24 Building Energy Efficiency Standards?
Cool roofs are included as a performance option in Title 24. Refer to Section 10-113 for information on certification and labeling requirements for reflectance and emittance of cool roof products. For the prescriptive compliance approach in the energy efficiency standards, view section 118 of Title 24. Sections 141, 142, and 151(b) outline the performance approach. For the latest applicable Standard see: www.energy.ca.gov/title24/
For updates and general information on Title 24 and to download the new Residential Manual (available August 2001), visit www.energy.ca.gov/title24/
Are cool roofs required in California's residential or nonresidential energy efficiency standards?
No, they are not required, but there are energy credits available to those who use the compliance options in the performance approach.
What specifications does a roof need to meet to be considered for credit under the Title 24 Standards?
Commercial and residential products must meet the following specifications according to the ASTM standards outlined below:
| ASTM | Tiles | Multiply or Liquid | |
| Solar Reflectivity | E903 or E1918 | 0.40+ | 0.70+ |
| Emittance Factor | E408 | 0.75+ | 0.75+ |
When did the Cool Roof Rating Council become the supervisory entity for cool roofs in California?
The Cool Roof Rating Council (CRRC) became the supervisory entity responsible for administering California's certification program for roofing products beginning January 1, 2003. At this time, every roofing product that is installed to comply with Title 24 will need to carry a packaging label that lists the product's reflectance and emittance as tested in accordance with ASTM standards.
For more information, see "Section 10-113 - Certification and Labeling of Roofing Product Reflectance and Emittance" of the Building Energy Standards. Until this time, all products must be ENERGY STAR® qualified. For a list of qualified products, visit www.energystar.gov
FLEX YOUR POWER