Title 24 has been a required design standard since 1978. With the establishment of the First Energy
Efficiency Standards for Residential and Non-residential buildings in response to a legislative mandate
to reduce California's energy consumption, the architect or designer now had two building code designs
to follow: The California Building code and the Building Energy Efficiency Program (as designed by
This second standard (The Building Energy Efficiency Program) has been updated over the years with
specific focus on electrical savings in the 2001 Title 24. This standard was the first of the
California standards to identify roofing membranes as a factor in saving energy (with the exception
of insulation which is normally required on a roof). For the first time, the 2001 Standard used the
term "cool roof" and established the procedures for certifying the roofing product. While the 2001
standard defined a "cool roof" and established procedures for certifying the roofing product, it was
offered as only an option and not a requirement. The state and utility companies offered financial
incentives to persuade owners to install cool roofing products on their buildings.
Title 24 2005
As an update to the 2001 standard, the 2005 version of Title 24 was approved in September 2004 and
mandated to go into effect on October 1, 2005. The focus on the update was mainly for commercial
construction. It tightened the requirements for most building components from windows to HVAC systems.
It also made mandatory the cool roof systems.
Certification and labeling of roofing products for reflectance and emittance are key to the new
standard. Every roofing product installed must have a clearly visible packaging label that lists both
the reflectance and emittance numbers certified by the Cool Roof Rating Council (CRRC). The CRRC
is the entity that supervises the certification program. There are mandatory requirements for both the
insulation and the cool roof.
The new standard mandates that the requirements for cool roofs are as follows:
- Any roofing product with an initial thermal emittance greater than or equal to 0.75 when tested
in accordance with the CRRC.
- Shall have a minimum initial solar reflectance of 0.70 when tested in accordance with the CRRC.
- Liquid applied roof coatings applied in the field as the top surface of a roof covering shall be
applied at a minimum dry mil thickness of 20 mils across the entire roof surface and meet the minimum
performance requirements listed.