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Nonresidential Outdoor Lighting Sources

Measure Description

This CASE Report for outdoor lighting consists of three submeasures: nonresidential lighting zone reclassification, nonresidential lighting power allowances for parking lots, and multifamily outdoor lighting power allowances.

Nonresidential Lighting Zone Reclassification

The outdoor lighting zone reclassification measure is proposed to align the California lighting zones with current industry standards employed across North America. Currently, lighting zones in California are classified with a United States(U.S.)Census-based approach which dictates lighting zones using the population-based classification of an area as “rural” or “urban”. This has resulted in overlighting many areas throughout the state.There are five lighting zones:

  • Lighting Zone 0 (LZ0): Includes undeveloped areas with essentially no artificial lighting.
  • Lighting Zone 1 (LZ1): Includes developed portions of government designated parks, recreation areas, and wildlife preserves.
  • Lighting Zone 2 (LZ2): Is defined as “rural” areas.
  • Lighting Zone 3 (LZ3): Is defined as “urban” areas.
  • Lighting Zone 4 (LZ4): Includes areas with maximum artificial lighting such as Times Square in New York City. Currently, no areas within California fall under LZ4.

This proposal revisits the current population-based approach and aims to provide more discretized lighting zone applications based on the U.S Census classifications; this would reduce energy use throughout California while minimizing sky glow2and light trespass.3Specifically, this proposal updates the lighting zone definitions to more closely match the Illuminating Engineering Society’s (IES) lighting zone definitions. The updated definitions would still rely on population density, but would specifically shift “rural” areas from LZ2 to LZ1:

  • LZ0: This is unchanged.
  • LZ1: Would still include developed portions of government designated parks, recreation areas, and wildlife preserves, but “rural” areas previously part of LZ2 would now be included here, along with residential and agricultural areas. “Rural” is defined as less than 2,500 people per square mile.
  • Lighting Zone 2 (LZ2): Was previously “rural” areas but is now “urban cluster” areas as well as mixed use residential, light commercial, and industrial areas. “Urban clusters” are defined as areas with between 2,500 and 50,000 people per square mile.
  • Lighting Zone 3 (LZ3): is still defined as “urban” areas, but now specifically includes high intensity commercial, entertainment centers, and heavy industrial and manufacturing. “Urban” areas are defined as greater than 50,000 people per square mile.
  • Lighting Zone 4 (LZ4): This is unchanged.

No change to the lighting power allowances (LPAs) associated with the current lighting zones have been proposed, this submeasure simply seeks to reclassify existing areas into more appropriate lighting zones.4This proposed change, which would modify Section 10-114, would impact new construction and alterations and additions in California.

A new section would be added to the nonresidential lighting compliance manual to document that luminaires installed on the project meet the backlight, uplight, and glare (BUG)rating requirements listed in Title 24, Part 11 (CALGreen). Luminaires installed within two mounting heights from the property line would be documented to confirm that they meet the CALGreen backlight and glare ratings based on their orientation towards the property lines. This would not result in additional field verification or acceptance tests beyond those that currently exist.

Nonresidential Lighting Power Allowances for General Hardscape

The LPAs for the general hardscape submeasure would update the existing prescriptive requirements for outdoor lighting, and would impact new construction, alterations, and additions across California. This measure would update the general hardscape LPAs for areas affected by the light level recommendations in the latest version of the IIES Recommended Practice (RP) 8-18 Addendum 1 to Chapter 17 (Illuminating Engineering Society 2020). This measure incorporates recent research that suggests task visibility plateaus at lower lighting levels than previously recommended, which prompted IES to revise the parking lot lighting levels to align with those recommended by IES prior to the IES RP-20-14 publication (republished as ANSI/IES RP-8-18 Chapter 17),which increased the recommended lighting levels. The Statewide CASE Team is proposing to reduce the prescriptive exterior lighting LPAs to reflect the revised parking lot lighting level recommendations.

Multifamily Outdoor Lighting Power Allowances

The Energy Commission is considering consolidation of low-rise and high-rise multifamily requirements under a new multifamily section in 2022 Title 24, Part 6. The multifamily outdoor LPAs submeasure proposes new LPAs for several new code sections that would be placed in the multifamily chapter of code being proposed for the Multifamily Chapter Restructuring Draft CASE Report. This submeasure creates limits for outdoor lighting that are more appropriate for circumstances and conditions associated with the residential nature of multifamily buildings.  

Relevant Documents

Measure proposals, supporting documents, and other outside references will be made public as they become available.

Round Two Utility-Sponsored Stakeholder Meeting Materials

Round One Utility-Sponsored Stakeholder Meeting Materials

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Draft CASE Report Now Available (Comments accepted until June 26, 2020)

This measure description will be updated as research is developed to support the 2022 code cycle. For questions or suggestions, email Include the measure name in the subject line.

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The Statewide CASE Team values input from all stakeholders engaged in the Title 24, Part 6 code change process. We encourage the open exchange of code change comments and concerns.

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