How Mountain View Handles Accessory Structures: A Practical Guide
Mountain View maintains 115 local ordinances across all categories, and 5 of those deal specifically with accessory structures. Here is a breakdown of what the city actually requires, what is prohibited, and where Mountain View falls on the strict-to-permissive spectrum compared to other cities.
Shed Rules
Sheds under 120 square feet do not require a building permit in Mountain View but must meet zoning setbacks and height limits. Larger sheds need a permit.
Key details: Permit exempt: Under 120 sq ft. Typical setback: 3 ft small, 5 ft larger. Height: Accessory limit. Front yard: Not allowed. Electrical: Permit required.
Contact your local code enforcement office for specific penalty information.
If you are coming from a city with tighter rules, you will find Mountain View gives residents more flexibility on shed rules.
Carport Rules
Carports in Mountain View require a building permit and must meet zoning setbacks. Front-yard carports are generally restricted to preserve neighborhood character.
Key details: Permit: Required. Typical setback: 5 ft side and rear. Front yard: Generally restricted. Open sides: Two for parking count. Height: Accessory zone limit.
Contact your local code enforcement office for specific penalty information.
ADU Rules
Mountain View ADU regulations follow California Government Code 65852.2 as amended by AB 68, AB 881, SB 13, and AB 1033. Ministerial approval applies to most ADUs and JADUs on single-family lots.
Key details: ADU per lot: One ADU plus JADU. Min max size: At least 1,200 sq ft. Setback: 4 ft side and rear. Height transit: Up to 18 feet. Review time: 60 days ministerial.
Contact your local code enforcement office for specific penalty information.
The rules around adu rules in Mountain View lean permissive, but that does not mean anything goes.
Tiny Homes
Tiny homes on foundations are regulated as ADUs in Mountain View. Movable tiny houses on wheels may be allowed as ADUs if they meet state movable tiny house standards.
Key details: Foundation tiny: ADU-regulated. Movable tiny: May qualify as ADU. Min size: 150 sq ft efficiency. RV as home: Not allowed. Utilities: Permanent connections.
Contact your local code enforcement office for specific penalty information.
Garage Conversions
Converting a garage to living space or ADU in Mountain View is allowed with permits. State ADU law waives replacement parking when the garage is converted to an ADU.
Key details: Permit: Always required. Min ceiling: 7 feet. Bedroom egress: Required. ADU parking: No replacement needed. Non-ADU parking: May be required.
Contact your local code enforcement office for specific penalty information.
The Bottom Line
Compared to many U.S. cities, Mountain View gives residents more room on accessory structures. 2 of the 5 rules here are rated permissive. But permissive does not mean unregulated. There are still requirements, and the city does enforce them when violations are reported.
All of the above reflects Mountain View's municipal code as of our last review. If you need specifics on fines, exemptions, or filing requirements, the detailed ordinance pages linked above have the full breakdown.