ADU rules in Solano County, CA — also called accessory dwelling unit regulations or granny flat ordinances — cover setbacks, owner-occupancy, parking, and permit requirements.
Solano County allows one Accessory Dwelling Unit and one Junior ADU per single-family lot in unincorporated areas under Solano County Code §28.72.10(B)(2), as amended by Ordinance 2020-1817 to conform with California Government Code §65852.2. Detached ADUs require 4-foot side and rear setbacks, and one off-street parking space is required unless the property is within ½ mile of public transit.
Section 28.72.10(B)(2) of the Solano County Zoning Code governs Accessory Dwelling Units in unincorporated Solano County. ADUs are permitted only on lots that already have an existing primary dwelling (§28.72.10(B)(2)(j)). The minimum side and rear setback is 4 feet from the lot line; the front setback follows the underlying zoning district per Table 28.31B or 28.32C. Maximum detached ADU floor area is 850 sq ft for a one-bedroom unit and 1,000 sq ft for a unit with more than one bedroom in the R-TC district, with up to 1,500 sq ft allowed in the R-R district (§28.72.10(B)(2)(f)). One on-site parking space per ADU is required under §28.94, which may be in the front or side setback or through tandem parking; no parking is required if the ADU is within ½ mile walking distance of public transit. Single-family lots may have both an ADU and a Junior ADU (JADU); the JADU must be carved out of the existing footprint of the primary dwelling or attached garage and capped at 500 sq ft.
Building an ADU without a building permit and zoning clearance is a violation of Solano County Code Chapter 28. Code Compliance may issue administrative citations, stop-work orders, and abatement notices requiring the unit to be brought into compliance or removed; ongoing violations can be recorded as a lien against the property.
Solano County, CA
Unincorporated Solano County has no leaf-blower-specific ordinance — no decibel cap, time-of-day restriction, or gas-blower ban beyond the general noise rule...
Solano County, CA
Unincorporated Solano County has no standalone amplified-music ordinance. Amplified sound is enforced through Solano County Code §21-10 (Disturbing the Peace...
Solano County, CA
Solano County Code §4-73 declares any dog, cat, fowl, or other animal that 'by habitual howling, yelping, barking or other noise disturbs or annoys persons i...
Solano County, CA
Unincorporated Solano County has no dedicated construction-hours ordinance. Construction noise is governed indirectly by Solano County Code §21-10 (Disturbin...
Solano County, CA
Unincorporated Solano County enforces nighttime quiet hours through Solano County Code §21-10 (Disturbing the Peace). Any non-agricultural noise that exceeds...
Solano County, CA
In unincorporated Solano County, commercial vehicles associated with a home-based business are limited by Solano County Code §28.72.40 (Home Occupations). Ty...
See how Solano County's adu rules rules stack up against other locations.
Help us keep this page accurate. If you notice an error or outdated information, let us know.