ADU Rules: Fairfield vs Vallejo
How do adu rules rules compare between Fairfield, CA and Vallejo, CA?
Fairfield and Vallejo have similar restriction levels.
Fairfield, CA
Solano County
Fairfield permits accessory dwelling units (ADUs) and junior ADUs (JADUs) on residential lots per FMC §25.20 and California Gov Code §65852.2/.22. Detached ADUs up to 1,200 sq ft and 16 feet tall; attached ADUs up to 50% of primary or 1,200 sq ft, whichever less. JADUs up to 500 sq ft. No additional density counted.
View full Fairfield rules →Vallejo, CA
Solano County
Vallejo regulates ADUs and JADUs under Vallejo Municipal Code Chapter 16.303 (Accessory Dwelling Units). Detached ADUs are capped at 1,200 sq ft, attached ADUs at 1,200 sq ft or 50% of the primary dwelling (whichever is less), and JADUs at 500 sq ft within the existing single-family structure.
View full Vallejo rules →Key Facts Comparison
| Fact | Fairfield | Vallejo |
|---|---|---|
| Max Detached | 1,200 sq ft / 16 ft | - |
| Max Attached | 50% primary or 1,200 sq ft | - |
| JADU Max | 500 sq ft | - |
| Side/Rear Setback | 4 ft (new construction) | 4 ft minimum |
| Code Sections | FMC §25.20 / Gov §65852.2 | - |
| Sale Separately | Not allowed (no AB 1033 opt-in) | - |
| Code Section | - | VMC Ch. 16.303 |
| Max Detached ADU | - | 1,200 sq ft |
| Max JADU | - | 500 sq ft |
| Detached Height | - | 16 ft |
Highlighted rows indicate differences between cities.
Fairfield FAQ
Can I rent my Fairfield ADU on Airbnb?
ADUs may only be rented for terms longer than 30 days. Short-term rental of ADUs under 30 days is prohibited by state law for any ADU permitted after January 1, 2020 (Gov Code §65852.2(a)(6)).
Can I sell my ADU separately from the main house in Fairfield?
No. AB 1033 allows separate-sale ADU condos only in cities that have opted in by ordinance. Fairfield has not adopted an AB 1033 ordinance as of 2026, so ADUs must remain on the same parcel as the primary residence.
Vallejo FAQ
How big can my Vallejo ADU be?
Under VMC Chapter 16.303, detached ADUs are capped at 1,200 sq ft and attached ADUs at 1,200 sq ft or 50% of the primary dwelling, whichever is less. JADUs are capped at 500 sq ft.
How long does it take to get a Vallejo ADU permit?
Vallejo issues a ministerial decision on a complete ADU application within 60 days, per VMC Chapter 16.303 and California Government Code §65852.2.
Can I rent my Vallejo ADU on Airbnb?
No. The recorded deed restriction required under VMC Chapter 16.303 prohibits short-term rental use. ADU rentals must be for 30 days or longer.
Compare other topics
See how Fairfield and Vallejo compare on other ordinance categories.
Want to add a third city?
Use our full comparison tool to compare up to three cities.
Open Comparison Tool