R316 Habitable Attics — 2025 California Residential Code

Habitable attics shall comply with Sections R316.2 and R316.3.

A habitable attic shall have a floor area in accordance with Section R312 and a ceiling height in accordance with Section R313.

A habitable attic shall be considered a story above grade plane.

Exceptions: A habitable attic shall not be considered to be a story above grade plane provided that the habitable attic meets all the following:

1. The aggregate area of the habitable attic is either of the following: 1.1. Not greater than one-third of the floor area of the story below. 1.2. Not greater than one-half of the floor area of the story below where the habitable attic is located within a dwelling unit equipped with an automatic sprinkler system in accordance with Section R309 .
2. The occupiable space is enclosed by the roof assembly above, knee walls, if applicable, on the sides and the floor-ceiling assembly below.
3. The floor of the habitable attic does not extend beyond the exterior walls of the story below.
4. Where a habitable attic is located above a third story, an automatic sprinkler system in accordance with Section R309 shall be installed in the habitable attic and remaining portion of the townhouse unit or dwelling unit or units located beneath the habitable attic.

The means of egress for habitable attics shall comply with the applicable provisions of Section R318.