California’s Title 24 for Steep Slope Roofs

Building Energy Efficiency Standards

California has issued a new code for steep slope roofs and energy conservation. Roofmax has been following most of these guidelines-now standards-but wants to communicate to you what is expected now so that you can be sure your roof is installed correctly.

These standards are provided by the GAF materials corporation. The following are excerpts from the GAF provided Title 24 materials:

About Title 24

The California Energy Commission (CEC) was created in 1974 through the Warren-Alquist State Energy Resources Conservation and Development Act to construct and periodically modify energy efficiency standards for residential and non-residential buildings.

In 1978, all building codes and standards were combined under one umbrella called Title 24 Building Standards Code and Part 6 of this standard code has the requirements for energy efficiency while part 1 has the administrative requirements. For more information or to download a copy of Title 24, visit

Why is Title 24 Now for Homes?

  • California has over 35 million people and from 1960 to 1974 when the CEC was created, they saw their energy consumption rise over 50% per capita, which means that not only as their population was increasing, the amount of energy each person was using was also increasing dramatically.
  • California’s building efficiency standards (along with those for energy efficient appliances) have saved more than $56 billion in electricity and natural gas costs since 1978. It is estimated the standards will save an additional $23 billion by 2013.
  • The CEC’s forecast data shows that 1/3 of the energy (natural gas and electricity) consumed in California is consumed by buildings.
  • Strengthening the requirements of Title 24 has been a very key element in the state’s climate change initiative.

Why Cool Roofs?

  • Roof surface temperatures and attic temperatures can be reduced significantly.
  • By lowering attic temperatures, air conditioning costs can be reduced by as much as 10-15% according to the Department of Energy’s ENERGY STAR program.
  • Reductions in air conditioning use help to reduce “peak energy demand” on the power grid, reducing the need for new power plant construction.
  • Cool roofs can reduce the effects of “Urban Heat Islands”, where data shows that urban areas have higher ambient temperatures than surrounding rural areas because of their concentration of dark surfaces and the sparseness of vegetation (dark surfaces can be up to 70F hotter on a warm summer day than reflective, “cool” surfaces).

When Does the Version of Title 24 That Includes “Cool Roofs” for Homeowners Go Into Effect?

Remember, Title 24 was first established in 1978 and has been the building standards code since then. The 2008 Building Efficiency Standards, Title 24 that has requirements for parts of California for “cool roofs” on residencies, goes into effect January 1, 2010.

Understanding How Title 24 Classifies Buildings

In addition to knowing where the building is located so you can know what is required, you need to know how Title 24 classifies “buildings”,

“Low Rise Residential”…describes:

  • All single family homes of any number of stories
  • All duplexes of any number of stories
  • All multi-family buildings up to 3 stories in height
  • Garden apartments and other housing types up to 3 stories in height


  • Offices, retail and wholesale stores
  • Grocery stores, restaurants, theaters
  • Hotels and motels
  • Industrial work buildings
  • Commercial or industrial storage units
  • Schools and churches
  • Apartment and multi-family buildings with four or more stories
  • Long-term care facilities
  • Dormitories
  • Private garages, carports, sheds and agricultural buildings

California Building Climate Zones

California Climate Zones

Title 24 Prescriptive Requirements

Steep Slope Roofs

Alternatives to using a cool roofing product for re-roofing–any of the following can be implemented in lieu of using cool roofing products for low-rise residential buildings:

  • Use of R-0.85 insulation or a 3/4″ air space added to the roof deck over the attic space, or,
  • Insulating and sealing existing air conditioning ducts in the attic space accordance with Section 151(f)10, or,
  • Buildings with no air conditioning in the attic (do not require cool roofs), or,
  • In zones 10, 12, or 13, providing ventilation of at least 1 sq. ft of free ventilation per 150 sq. ft. of attic floor space and where at least 30% of the ventilation is within 2 feet of the ridge, or,
  • Having a minimum of R-30 ceiling insulation, or,
  • Installing a radiant barrier that meets the requirements of Section 151(f)2, or,
  • In zones 10, 11, 13, or 14, having a minimum R-3 deck insulation above a vented attic.

How Roofmax is Complying With Title 24 Requirements

  • Use of R-0.85 insulation or a 3/4″ air space added to the roof deck over the attic space.
  • Existing ducts insulated and sealed in the attic space in addordance with section 151(f)10.
  • In climate zones 10, 12 or 13 providing ventilation of at least 1 sq. ft. of free ventilation per 150  sq. ft. of attic flow space and where at least 30% of the ventilation is within 2 feet of the ridge.
  • Building has a minimum of R-30 ceiling insulation.
  • Installing radiant barrier meeting the requirement of Section 151(f)2.

If you have any questions about title 24, please feel free to call our office at 925-685-4151.



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