Did you Know?

Perspectives
A Quarterly Information Source from Benchmark, Inc.
Volume 54 September 2005

Did you Know?

by Gilbert Arnold, RRC

California’s Title 24

Title 24 is part of California’s Energy Efficiency Standards for Residential and Nonresidential buildings, and was developed in response to the rolling blackouts they experienced in 2000 and 2001. It establishes energy budgets for every building in the state. Its main emphasis is to lower statewide energy use during peak demand periods. Title 24 affects Benchmark because we design roofs in California, and history shows that other states frequently adopt California’s progressive initiatives.

Title 24 governs energy use in all commercial buildings in the state as well as homes. It dictates all aspects of energy consumption including lighting, windows, doors, heating and cooling systems, insulation and appliances. All new construction, renovations and additions for which a building permit is issued after October 1, 2005 must meet the requirements of Title 24.

Any nonresidential roof with a low slope (<2:12) must meet the requirements of Title 24 when over half of the roof or more than 2,000 square feet is replaced or recovered. Title 24 has the following requirements:

o Initial thermal emissivity of > 0.75

o Initial solar reflectance of > 0.70

o Emissivity and reflectance must be tested and certified by the Cool Roof Rating Council (CRRC)

o Minimum insulation requirements based on climate zone

Solar reflectance is the fraction of solar energy the surfacing reflects back into the atmosphere. White membranes have the highest solar reflectivity while black has the lowest. Infrared emissivity or emittance is a measure of the ability of a surface to shed some of its heat (in the form of infrared radiation) away from the surface (i.e.; roofing membrane). High infrared emissivity helps keep surfaces cool.

White coatings dominate the CRRC list of materials that meet Title 24 requirements. Most white granulated modified bitumens do NOT meet the minimum solar reflectance requirements while metal does not meet the emissivity minimum unless it has a special coating. Gravel is not acceptable except in very limited circumstances.

The above is a brief synopsis of Title 24 requirements. For more information on Title 24, go to www.energy.ca.gov/title 24.