Federal Lighting Standards
The American National Standards Institute, American Society of Heating and Refrigeration Engineers, and Illuminating Engineering Society Standard 90.1 (ASHRAE 90.1) is an energy use standard that defines minimum requirements for energy-efficient non-residential buildings and outdoor applications. ASHRAE 90.1 is a construction industry standard, not a regulation. First issued in 1975, it was adopted in 1992 by the U.S. government as regulation for federal buildings only. Many states have also adopted it as their state building code. Currently ASHRAE 90.1-2004 is the reference for “green” building standards such as Leadership in Energy and Environmental Design (LEED) 2009.
The 2004 issue of ASHRAE 90.1 was the first to introduce outdoor lighting power limitations and environmental zones for non-residential properties; however, it did not cover municipal street or pedestrian lighting systems. ASHRAE 90.1 today still does not cover municipal street lighting systems. There are currently no federal energy use regulations for public street lighting systems.
State of California Lighting Regulations
In 2001, State Senate Bill 5X mandated that the California Energy Commission (CEC) create energy efficiency standards to regulate exterior lighting for permitted spaces. In response, the 2004 update to Title 24 (T24) of the California Building Standards Code included outdoor lighting energy use standards for building grounds, entries, parking lots, landscape, building facades, sales areas and signage; lighting standards for public streets, roadways and highways, sports and athletic fields and industrial sites are excluded.
T24 standards set maximum allowed lighting power use within defined areas. The allowed power varies by "environmental zone" based on population density as is illustrated in the chart below. Zones LZ1 and LZ3 would apply within San Francisco.
In addition to T24, the State of California has a new building code known as the 2010 California Green Building Standards Code (CALGreen), which went into effect on January 1, 2011. CALGreen sets lighting power allowances for all outdoor lighting in an effort to promote sustainable practices. Exemptions apply where more than 50% of the light from a fixture is used to light areas such as public streets.
San Francisco street and pedestrian lighting is exempt from power allowance limitation in both T24 and CALGreen. Both codes, however, provide for light pollution reduction measures. The measure calls for all exterior fixtures with lamps rated for greater than 175W to include Cutoff optics, or be shielded. Street and pedestrian lighting is not exempt.