SB 1211 for 6-unit apartment Buildings
6-unit apartment owners are among SB 1211's clearest beneficiaries. A 6-unit small apartment. Up to 6 detached ADUs under SB 1211.
The math, explained
SB 1211 caps detached ADUs at the lesser of 8 or your existing unit count. A 6-unit 6-unit apartment lot therefore qualifies for 6 detached ADUs. The interior-conversion rule (max(1, ⌊units × 25%⌋)) adds 1 more, for a total of 7.
Design playbook for mid-size multifamily (5–8 unit)
This is SB 1211's sweet spot. A 6-unit existing building maxes out the 8-detached cap (or comes close), so design moves are about packing detached ADUs efficiently around the existing structure and converting underutilized parking.
Cost expectations
At this scale, GC bids stabilize. Expect $260–$400/sf stick-built, $200–$300/sf modular, with 8-unit projects getting the best per-unit pricing because crews stay mobilized.
What to watch out for
Title 24 energy compliance, fire-flow water service, and trash-enclosure relocation are the most common late-stage corrections.
Get a personalized SB 1211 feasibility report for 6-unit apartment owners
3 minutes. We email you a 4-page PDF with your buildable count, parking determination, jurisdiction overlays, and pro-forma.
No spam · free · delivered in 24 hrs