City of Los Angeles Ordinance No.183149: Cool Roof for Reduction of Heat Island Effect

The Los Angeles City Council amended the city's Green Building Code to require that all new residential roofs be "cool roofs." The amendments require cool roofs on new and refurbished homes in Los Angeles and sets minimum requirements for cool materials. Starting on October 1, 2014, residential roofing materials were required to meet certain values for their solar reflectance index (a combined measure of solar reflectance and thermal emittance).

Cool roofs reduce energy use in homes and external temperatures by reflecting more sunlight than traditional roofs. Utilized on a large scale, cool roof technology can help mitigate Los Angeles' "urban heat island," a phenomenon in which concrete and building density make urban areas hotter than surrounding less-developed areas. Increasing average temperatures and extreme heat associated with climate change are expected to exacerbate Los Angeles' urban heat island. The city hopes that the cool roof ordinance will mitigate the urban heat island effect, save energy, limit smog formation, and reduce heat-related health illnesses and fatalities.

The Los Angeles Department of Building and Safety is tasked with permitting cool roofs and inspecting their installation.

The Los Angeles Department of Water and Power has broadened its cool roof incentives to support the transition and offers rebates to qualifying cool roofs to offset some installation costs.

The ordinance exempts the following processes and roofs from the cool roof requirement:

  • Roof repair,
  • Certain roof replacements,
  • Roofs with building-integrated solar panels, and
  • Permits issued prior to January 1, 2015 for the replacement of an existing roof with asphalt shingles or composition roll roofing (mats used for roofing made up of the same materials as asphalt shingles).

This ordinance was unanimously passed on July 2, 2014 and the code went into effect on January 1, 2015 after a grace period allowing the roofing industry to prepare for enforcement.


Publication Date: July 2, 2014

Related Organizations:

  • Los Angeles City Council
  • City of Los Angeles, California


Resource Category:

Resource Types:

  • Laws

States Affected:


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