SB 1211 for 6-unit apartment in San Mateo
In San Mateo, a 6-unit 6-unit apartment just became one of the highest-yield SB 1211 typologies — 7 new homes, ministerially approved. At San Mateo's median rent of $3,000/mo, that's ~$252K in additional gross annual rent.
The San Mateo scenario
The capital stack on a typical San Mateo 6-unit apartment project: existing equity (the lot itself, owned outright in many cases), construction loan against the new ADU appraised value, refi at completion against the stabilized rent roll.
San Mateo-specific note: Peninsula tech rents; very strong upside.
Mid-size multifamily (5–8 unit) design playbook
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.
Pro-forma snapshot
| Existing units | 6 |
| Detached ADUs (SB 1211) | 6 |
| Interior conversions | 1 |
| Total new units | 7 |
| Median 1BR rent in San Mateo | $3,000/mo |
| Est. additional gross rent | $252K/yr |
| Estimated total project cost | ~$1,725K |
| Year-1 NOI estimate | ~$189K |
| Stabilized cap rate at cost | 11.0% |
| Replacement parking required | No (§66313) |
| Approval pathway | Ministerial · §66314 |
| Typical permit timeline in San Mateo | 75-130 days |
Get a personalized SB 1211 feasibility report for 6-unit apartment owners in San Mateo
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