Energy Standard

ASHRAE 90.1 — Commercial Lighting

ASHRAE 90.1 is the primary commercial building energy standard referenced by building codes in 49 US states. It sets lighting power density limits, mandatory control requirements, and exterior lighting zone restrictions for all commercial occupancy types.

Key Requirements for Lighting

▸Interior LPD limits apply to all commercial spaces — two compliance paths: building area method and space-by-space method
▸Automatic shutoff controls required within 20 minutes of occupants leaving
▸Daylighting controls required in spaces with windows greater than 150 sq ft with adequate illuminance
▸Occupancy sensors or time switches required in most space types
▸Exterior lighting must comply with power allowances and cutoff requirements by lighting zone

ASHRAE 90.1 vs Title 24

California Title 24 is generally more stringent than ASHRAE 90.1 — products that comply with Title 24 will typically meet ASHRAE 90.1 requirements. For projects outside California, ASHRAE 90.1 is the governing standard in most states.

EC Note: Which Code Applies?

The applicable energy code depends on the project location and building permit date. Most states have adopted IECC 2018 or IECC 2021, which reference ASHRAE 90.1 as an alternate compliance path. Always confirm the adopted code with the local building department before specifying.

ASHRAE 90.1 Compliant Products

We'll verify compliance and provide EC pricing for your project specs.