ADU rules in San Rafael

Detached ADUs are allowed by right on any lot zoned for single-family or multifamily residential use with an existing or proposed home: Table 14.04.020 marks ADUs and JADUs "P" (permitted by right) in the R, DR, MR, HR and PD districts, and Table 14.05.020 marks them "P" in the GC, NC, O, C/O, R/O and FBWC districts. A compliant unit needs only a building permit. Beside the local-standards unit (up to 1,000 sq ft), subsection E guarantees the state-exempt detached unit of up to 800 sq ft with 4 ft side and rear setbacks (Gov. Code 66323(a)(2)). On a multifamily lot the local cap of two detached ADUs (E.4) yields to the state count of up to eight, never more than the existing units (66323(a)(4)(A)(ii)).

Attached additions, internal conversions of the home or of an existing accessory structure, and JADUs (up to 500 sq ft within the walls of a single-family home) are all allowed by right in the same districts. Conversions have no size cap and need no new setbacks, with up to 150 sq ft of expansion for ingress and egress (E.1; Gov. Code 66323(a)(1)). In multifamily buildings, ADUs may be created only in existing non-livable space, at least one and up to 25 percent of the existing units (E.3; 66323(a)(3)). One JADU is allowed per lot (C.2.a).

Table 14.16.285 caps a detached ADU at 1,000 sq ft and an attached ADU at 1,000 sq ft or 50 percent of the existing home, whichever is less; the city page and Gov. Code 66321(b)(3) guarantee at least 800 sq ft whatever the percentage, lot coverage or floor area ratio. Internal conversions are uncapped, JADUs are limited to 500 sq ft, the minimum unit is 150 sq ft, and the state-exempt detached unit is capped at 800 sq ft (E.2). The table's 16 ft height for every new unit yields to Gov. Code 66321(b)(4): 16 ft detached, 18 ft within one-half mile of a major transit stop or high-quality transit corridor (plus 2 ft for a matching roof pitch) or on a lot with a multistory multifamily building, and 25 ft or the zone's lower limit attached; the city page already applies those heights, with 17 ft in the Eichler-Alliance overlay. Since 1-1-2026 the state minimums are measured in interior livable space, while the local text speaks of floor area. The 2021 ordinance is exposed to Gov. Code 66316 after HCD's unanswered 2-27-2026 repeal-request letter; a void reading would substitute the state default of 1,200 sq ft detached (66314(d)(5)).

No owner-occupancy rule applies to ADUs: 14.16.285 imposes none and Gov. Code 66315 bars one. The codified JADU clause (C.2.c) still requires owner occupancy for every JADU, but since 1-1-2026 Gov. Code 66333(b) allows that only when the JADU shares sanitation facilities with the main home, so a JADU with its own bathroom needs no owner on site. A recorded JADU deed restriction barring separate sale and fixing its size remains required (C.2.d; 66333(c)).

The code requires one space per new attached or detached ADU, which may be tandem on a driveway, anywhere on the lot, covered or uncovered, but none for internal conversions, JADUs, units within one-half mile walking distance of public transit, units in a historic district, where on-street permits are not offered to the occupant, or within one block of a car-share vehicle (C.5.b). The city page adds the state exemption for an ADU applied for together with a new home (Gov. Code 66322(a)(6)), and subsection E state-exempt units carry no parking standard (66323(b)). Garages, carports or covered spaces demolished or converted for an ADU need not be replaced (C.5.c), and 66314(d)(11) extends that to uncovered spaces. On a plain reading of 66314(d)(10)(A) (one space per unit or per bedroom, whichever is less), the flat one-space rule cannot reach a studio ADU.

Ministerial: an ADU or JADU meeting the standards "shall only be subject to issuance of a building permit" with no discretionary review or public hearing (14.16.285.C), applications are filed online as a General Permit Requiring Plan Review, and the city must act within 60 days of a complete application (D.1; Gov. Code 66317(a)(3)). State law adds the 15-business-day completeness notice and a written appeal path to the Council or Planning Commission (66317(a)(2), (d)), which the 2021 code lacks. Subsection E units (conversions, the 800 sq ft detached unit, multifamily conversions and detached units) are approved ministerially without the local development and design standards.

ADUs and JADUs may be rented but not sold separately from the main home (C.2.b, C.4.b), except through the qualified-nonprofit path the code cites as legacy 65852.26 (now Gov. Code 66341); no ADU condominium opt-in under 66342 was found. Ordinary local-standards ADUs have no minimum rental term and may be offered as short-term rentals (under 30 days) through the city's Short-Term Rental Program (Chapter 10.110 and Resolution 14737, 2019): the host must be a Permanent Resident whose primary residence is on the property, must register annually ($170 first time, $135 renewal) and remit transient occupancy tax, and may not rent the whole main home and the ADU at the same time. State-exempt units under subsection E must be rented for terms longer than 30 days (Gov. Code 66323(e); the local E.5 says not less than 30 days), and since 1-1-2026 so must JADUs (66333(g)), overriding the city FAQ that lists JADUs as eligible short-term rentals.