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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. This is a prescriptive submeasure that will impact new construction and alterations, and additions in California. Currently, lighting zones in California are classified with a United States (U.S.) Census-based approach which dictates lighting zone using the population-based classification of an area as “rural” or “urban”. This has resulted in over lighting many areas throughout the state. This proposal revisits the current population-based approach and aims to provide more discretized lighting zone applications based on the population density within each zip code; this will save energy throughout California while minimizing sky glow and light trespass. No change to the lighting power allowances (LPAs) associated with the current lighting zones has been proposed, this submeasure simply seeks to reclassify existing areas into more appropriate lighting zones. No new field verification or acceptance tests beyond those that currently exist will be required, and no new system or technology requirements will be required.

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.

Multifamily Outdoor Lighting Power Allowances

This CASE study investigates energy savings and cost effectiveness of reducing the outdoor lighting power allowance (LPA) for multifamilyspecific applications 

The study additionally explores elimination of the perimeter allowance from the calculation of the general hardscape allowance to simplify the process of determining the total lighting power allowance. Most outdoor space that is assigned a lighting allowance falls under general hardscape. The total allowance for general hardscape is calculated by combining a site allowance, a perimeter allowance, and an area allowance. Additionally, there are a variety of outdoor LPAs that are permitted to be “layered” on top of the general hardscape allowance if certain conditions exist. This combined calculation approach was developed in the 2005 version of the Title 24, Part 6 Standards and subsequently expanded to accommodate the need for more LPA for properties with complex geometries.  

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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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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