Title 24 Parking Garage Lighting Requirements
A garage needs partial-OFF occupant sensing that drops lighting power to between 20 and 50 per cent of full power, with no more than 500 watts controlled as a single zone — plus daylight responsive controls near openings at a threshold of just 60 watts.
Partial-OFF, not off
Parking garages, parking areas and loading and unloading areas all require occupant sensing controls of the partial-OFF kind. When the zone is vacant the control has to uniformly reduce lighting power to somewhere between 20 and 50 per cent of full power, using at least one control step. It does not go dark, and it is not permitted to.
That is a deliberate difference from an office, where vacancy can mean off. A garage keeps a floor level of light for safety and for cameras, so the code asks for a reduction it can verify rather than a shutoff it cannot allow.
The 500-watt zone cap is the part that drives cost
No more than 500 watts of rated lighting power may be controlled together as a single zone. On a large deck this is the requirement that decides the design, because it sets how many independently sensed zones the garage needs — and therefore the sensor count and the wiring.
Work it the other way round and it becomes a planning number: divide the connected load by 500 and that is the minimum number of control zones, before any consideration of layout. Discovering this after the fittings are selected is how garage relights go over budget.
Sixty watts near an opening, not seventy-five
Garages have their own daylight trigger, and it is lower than the one for enclosed spaces. Where the total installed wattage of general lighting in the primary and secondary sidelit daylit zones reaches 60 watts or greater, that lighting has to be on daylight responsive controls.
Two things differ from the general rule. The threshold is 60 rather than 75, and the primary and secondary sidelit zones are counted together as one combined area rather than assessed separately. Any garage with an open façade, a ramp mouth or a generous stair opening will reach 60 watts across those combined zones almost immediately.
Why open-air decks and enclosed decks differ
The distinction that matters on site is how much daylight actually reaches the bays. A top deck open on three sides has extensive sidelit zones and a substantial daylight scope; an interior level with a single vehicle opening has a small zone near the mouth and very little beyond it. Both still need the occupant sensing throughout.
This is why a garage is rarely one uniform lighting design. Levels get assessed separately, and a compliance approach copied from the top deck to the basement will be wrong in one direction or the other.
Both control types are acceptance tested
The occupant sensing goes on NRCA-LTI-02-A Shutoff Lighting Controls and any daylight responsive control on NRCA-LTI-03-A, both completed by a technician certified for lighting controls. Garages test badly when zones were combined past 500 watts in the field to save cable, because that is visible in the test rather than arguable.