In San Pablo you can build a detached ADU up to 800 sq ft
guaranteed (1200 sq ft ceiling), 16 ft tall,
set back 4 ft from side and rear property lines.
Owner-occupancy is not required.
Parking is capped at 1 space and is waived entirely in six situations,
including within half a mile of transit. Because the state found San Pablo's ordinance non-compliant, these are state figures and the city's own ordinance does not currently govern.
Gov. Code §§ 66310–66342 · 38 of 51 fields checked against statute text
California's Department of Housing and Community Development reviewed San Pablo's accessory dwelling unit ordinance and found it does not comply with State ADU Law. Under Gov. Code § 66316 a non-compliant ordinance is null and void in its entirety, and state standards apply instead. Every figure below therefore comes from state statute, not from the city's code.
Ordinance status · derived from HCD review letters
Status was derived MECHANICALLY from the ingested HCD letter by literal keyword match ("failstocomplywithstateadulaw"), not by human review. The letter appears to contain 13 numbered findings, which have NOT been curated. Statutes cited: 65852, 66310, 66314, 66315, 66317, 66321, 66323, 66326, 66342. HCD letters expressly permit a jurisdiction to disagree with findings, so this is strong evidence but not an adjudication. Confirm with the jurisdiction before relying on it.
Quoted from the state's letter
What San Pablo was told to change
All 24 of them, word for word. Nothing here is paraphrased, because paraphrasing a legal requirement is how error gets in.
provide · 2026-05-20
The City must provide a written response to these findings no later than June 19, 2026, with a plan to either amend the current ordinance or adopt a resolution with findings.
amend · 2026-05-20
The City must amend the Ordinance to refer to the correct Government Code sections.
amend · 2026-05-20
The City must amend its Ordinance to allow the full allotment and combination of both 66314 and 66323 for lots with both single-family and multifamily primary dwelling units.
multifamily lot counts
amend · 2026-05-20
The City must amend the Ordinance to provide for two detached ADUs with a proposed multifamily primary dwelling.
multifamily lot counts
amend · 2026-05-20
The City must amend the Ordinance to provide existing multifamily primaries up to eight detached ADUs, not to exceed the number of primary dwellings on the lot.
multifamily lot counts
amend · 2026-05-20
The City must amend the Ordinance to remove the deed restriction requirement for an ADU.
provide · 2026-05-20
The City must provide for the ministerial combination of units created subject to sections 66323 and 66314.
ministerial review
provide · 2026-05-20
The City must provide for all state-mandated ADU combinations.
provide · 2026-05-20
The City must provide for these maximum sizes.
provide · 2024-04-24
The City must provide a written response to these findings no later than May 24, 2024.
amend · 2024-04-24
The City must amend the Ordinance accordingly.
amend · 2024-04-24
The City must amend the Ordinance to add internal access when required.
amend · 2024-04-24
The City must amend the Ordinance to include a denial process consistent with State ADU Law.
amend · 2024-04-24
The City must amend the Ordinance to comply with State ADU Law.
amend · 2024-04-24
The City must amend the Ordinance to allow for a front setback exception to comply with State ADU Law.
setbacks
other · 2024-04-24
The City must clarify the Ordinance to prevent confusion and inconsistency with State ADU Law.
remove · 2024-04-24
The City must remove the 30-day minimum rental requirement for JADUs and amend the Ordinance to comply with State JADU Law.
JADU · rental term
amend · 2024-04-24
The City must amend or remove this section.
other · 2024-04-24
The City must either amend the Ordinance to comply with State ADU Law or adopt the Ordinance without changes.
other · 2024-04-24
The City must include findings in its resolution that explain the reasons the City finds that the Ordinance complies with State ADU Law despite the findings made by HCD.
amend · 2023-06-15
The City must amend the Ordinance to add "existing or proposed single-family.
other · 2023-06-15
The City must note the exceptions and amend the Ordinance to comply with State ADU Law.
amend · 2023-06-15
The City must amend the Ordinance to reflect current statute.
Important, and worth checking before you rely on it: the state reviewed San Pablo's ADU rules on 2026-05-20 and said they break state law. When that happens the law says the city's rules stop counting and the state's rules apply instead, which is usually better for you because the state's are more generous. A city is allowed to disagree with the state and keep its rules in place while it argues, so this is a strong position to take rather than a settled fact. The practical move: if a planner quotes you something stricter than the numbers below, ask which rule they are relying on given the state's findings, and confirm with the planning department whether the city has since fixed its ordinance.
What you can build. You can build a separate building in the yard, an addition attached to your house, or a conversion of space you already have, like a garage.
How many. On a normal single-family lot you can have 1 ADU, plus 1 "junior" ADU, which is a small unit carved out of the existing house.
How big. The city has to let you build at least 800 square feet. If you want two or more bedrooms, it has to allow up to 1000 square feet. For reference, 800 sq ft is roughly a one-bedroom apartment, about the size of a two-car garage.
How close to the property line. You need to leave 4 feet on the sides and 4 at the back. That is measured from your property line, not from the fence, and those are not always in the same place. If you are converting a garage that already sits closer than that, you can generally keep it where it is.
How tall. Up to 16 feet, which is a single storey with a normal roof. If your lot is within a half mile walk of a major transit stop, you get 18 feet instead.
Parking. You may need to add 1 parking space, but there are a lot of exemptions. The big one: if you are within a half mile walk of public transit, no parking is required. And if you convert your garage, nobody can make you rebuild the parking you lost.
Common questions
Is San Pablo's ADU ordinance currently valid?
California's Department of Housing and Community Development found it non-compliant on 2026-05-20. Under Gov. Code § 66316 a non-compliant ADU ordinance is null and void in its entirety and state standards apply instead. The city may disagree and contest the findings, so confirm current status with the planning department.
How far from the property line does an ADU have to be?
4 feet from the side and rear property lines (Gov. Code s 66323(a)(2)). No setback at all is required if you convert an existing structure such as a garage that already sits closer (Gov. Code § 66314(a)(7)).
How tall can it be?
16 feet for a detached ADU (Gov. Code s 66321(b)(4)(A)), rising to 18 feet within half a mile walking distance of a major transit stop, plus 2 more feet to match the roof pitch of the main house. Attached ADUs may reach 25 feet or the primary dwelling's limit, whichever is lower.
Do I have to live on the property?
No. California bars a local agency from imposing an owner-occupant requirement on an ADU (Gov. Code s 66315). A junior ADU is different: owner-occupancy can still be required there.
Do I need to add parking?
At most one space (Gov. Code s 66314(d)(10)(A)), and six statutory exemptions remove it entirely, including within half a mile walking distance of public transit, within a historic district, or with a car share vehicle within one block (Gov. Code § 66322(a)). Converting a garage never obliges you to replace the lost parking.
Can I put it on Airbnb?
No. Rentals shorter than 30 days are barred, and for units approved on the by-right track that bar is mandatory rather than optional (Gov. Code § 66323(e)).
In the surrounding area
What the state found next door
How San Pablo's neighbours fared in the same review process.
Across Contra Costa County the state has reviewed 9 ordinances and found 9 of them non-compliant.
Next steps
Before you rely on any of this
Bring up the state's findings letter for San Pablo if a planner quotes you a stricter rule. The letter is public and is linked in the compliance output.
Find your exact lot size and where your property lines actually are. A survey beats a fence.
Call the planning counter and ask what zoning district your parcel is in, and whether any overlay applies (historic, hillside, fire hazard, flood).
Ask whether your lot is within a half mile walk of transit. That one answer changes parking and height.
If you are in an HOA, read the CC&Rs. State law limits outright HOA bans, but the details still matter.
Get the utility and sewer connection requirements in writing early. They are often the surprise cost.
Who builds them
No builder list for San Pablo yet
Rather than list contractors we cannot evidence, this stays empty until San Pablo
publishes permit records naming them or licence matching reaches the city. The
cities already covered show how the ordering works, and whichever contractor
you use, the rules above are the ones that govern the job.