Title 24 Issues

On January 1, 2010, the State of California implemented significant changes to the “Title 24 Building Energy Efficiency Standards”. It is now mandatory in California that existing roofs comply with the requirements of these Standards when they are replaced, recovered or recoated. There are a few exceptions to this requirement (such as qualified Historic Buildings, etc.).

The current Energy Standards are extremely complicated and can be very frustrating. Evans Roofing Company can help to simplify this process. If you have questions or would simply like our help, give us a call or send us an e-mail.

Current Title 24 Roof Requirements:

Title 24 Energy Standards must be complied with on nonresidential buildings, high-rise residential buildings and hotels/motels where more than 50 percent of the roof or more than 2,000 square feet of roof, whichever is less, is being replaced, recovered or recoated.

Title 24 Energy Standards must also be complied with on low-rise residential buildings when more than 50 percent of the roof or more than 1,000 square feet of roof, whichever is less, is being replaced. Buildings are considered “low-rise” if they are three (3) stories high or less.

The requirements only apply to roof areas over “conditioned space”. Conditioned space means any portion of the building that is either heated or air conditioned.

There are different requirements for different types of buildings. The Energy Standards basically groups the building types into these categories:
  • Non-Residential Buildings
  • Low-Rise Residential Buildings (3 stories high or less)
  • High-Rise Residential Buildings (more than 3 stories high)
  • Hotel/Motel Buildings
There are also different requirements, based upon the geographical location of the building. The Energy Standards divide the State of California into 16 different Climate Zones. (Don’t worry, Evans can help!)

One of the critical changes to Title 24 is that roof insulation is now required when existing roofs are removed down to the roof deck or to down to recover boards. This requirement applies to nonresidential buildings, high-rise residential buildings, hotels and motels. The amount of required insulation varies, depending upon building type and geographical location. There are some exceptions to this requirement. (Once again……Don’t worry, Evans can help!)

In order to comply with the California Energy Standards, one of these two types of Approaches must be used:

Performance Approach:

This approach is normally used in new construction. To comply with the Energy Standards, all energy related aspects of the building are considered (roofs, walls, windows, doors, etc.). Under this approach, complicated formulas must be used to calculate the overall energy efficiency of the building. Because of the difficult nature of this approach, these calculations are normally done by professional engineers, architects or consultants. The calculations are then submitted to the Building Department for approval. Fortunately, there is a simpler way to comply with the Energy Standards. This easier method is called the Prescriptive Approach.

Prescriptive Approach:

This approach is usually used when existing roofs are reroofed or coated. It simply requires that the work comply with specific requirements described in the Title 24 Building Energy Efficiency Standards. These requirements relate to installing surface materials that conform to the Reflectance and Emittance requirements stated in Title 24. Reflectance refers to “the fraction of incident radiation reflected by a surface”. Emittance refers to “the relative ability of a surface to emit energy by radiation”. The specific Reflectance and Emittance requirements vary, depending upon the type of building and the geographic location.

The Prescriptive Approach also requires that roof insulation be installed, when required by Title 24. The specific insulation requirements also vary, depending upon the type of building and the geographic location.


To learn more about Title 24, visit http://www.energy.ca.gov/title24/index.html. Make sure you are reviewing the 2008 Version of Title 24 (which became effective on January 1, 2010).

You can also call the Energy Standards Hotline at (800) 772-3300.