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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

This measure would modify the outdoor lighting zone (LZ) classifications so they would be based on land use (rural, suburban, and downtown areas) instead of population. This change would result in energy savings throughout the state. At present, 90percentof California nonresidential outdoor lighting is classified as Illuminating Engineering Society (IES) LZ3, which is used to describe city centers. Many of the areas that are currently classified as LZ 3could be reclassified as either LZ1 (rural area) or LZ2 (suburban area). If a repeatable, unambiguous method of determining outdoor LZs can be developed that results in a more accurate classification per the IES LZs definitions, the state could realize energy savings and benefit from reduced light pollution. The Statewide CASE Team may rely on a region’s zoning designations to determine new LZs but will investigate the best approach.

Nonresidential Lighting Power Allowances for Parking Lots

This measure would update the lighting power allowances (LPAs) for areas affected by the updated light level recommendations in the latest version of the Illuminating Engineering Society (IES) recommended practice (RP) IES/ANSI RP-8-18 Addendum 1 Chapter 17 Parking Lots and Parking Garages, which is currently under review and pending publication. The Statewide CASE Team expects the recommended light levels to be lowered. The prescriptive exterior lighting LPAs would be reduced to reflect the revised recommended practices. The measure also looks to re-assess the need to distinguish between asphalt and concrete surfaces, which currently have different LPA specifications in Title 24, Part 6.

Research completed in Fall 2018 by the Virginia Tech Transportation Institute (VTTI) has found that visibility improvements in parking lots may plateau at lower light levels than those recommended in the current version of IES/ANSI RP-8-18 Chapter 17. Due to this research, and addendum to RP-8-18 is currently under review and is expected to reflect the new research findings by recommending lower light levels for parking lots. Lower light levels would improve energy savings in California since less energy would be required to provide the illumination recommended for parking lots.

VTTI’s research also indicates that the difference in the light level requirements between asphalt and concrete surfaces in parking lots may be insignificant. The finding is expected to be adopted in the IES/ANSI RP-8-18 Addendum 1. This will result in lowered light level recommendations, which require less lighting power, and thereby result in additional energy savings in California. This measure may reduce complexity in the Standards, which may improve compliance.

Relevant Documents

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

Provide Feedback

This measure description will be updated as research is developed to support the 2022 code cycle. For questions or suggestions, email info@title24stakeholders.com. Include the measure name in the subject line.

Give Us Your Feedback

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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