Before You Build in Sunnyvale, CA: Permit & Rule Checklist (2026)

Retaining walls over 4 feet measured from the bottom of the footing require a Sunnyvale building permit with engineered plans, including drainage, soil pressure, and seismic analysis.

California Health and Safety Code 115920 and Sunnyvale code require pool barriers at least 60 inches tall with self-closing gates and at least two of seven safety features for residential swimming pools.

Sunnyvale limits front yard fences to 3 feet, side and rear yard fences to 6 feet, and allows up to 8 feet with a minor fence permit for privacy and sound attenuation needs.

Fences up to 6 feet in side and rear yards do not require a building permit in Sunnyvale, but fences over 7 feet, retaining walls over 4 feet, and pool barriers always need permits.

California Civil Code 841 (Good Neighbor Fence Act) requires adjoining property owners to share the cost of boundary fences equally absent written agreement, and 30-day written notice before construction.

Sunnyvale requires a building permit for any in-ground pool or spa, and for above-ground pools deeper than 18 inches, under the California Building Code as adopted by SMC Title 16.

Hot tubs and spas in Sunnyvale require a building permit and must meet California Pool Safety Act rules, but a locking safety cover meeting ASTM F1346 satisfies barrier requirements.

Sunnyvale enforces the California Swimming Pool Safety Act (H and S Code 115920). Pools require enclosures at least 60 inches tall with self-closing, self-latching gates.

Sunnyvale pools must have anti-entrapment drain covers per VGB Act, approved circulation and chemical systems, and comply with California Pool Safety Act.

Above-ground pools deeper than 18 inches require a Sunnyvale permit and must meet Pool Safety Act barriers. Pool walls at least 48 inches may serve as part of the barrier.

Sunnyvale allows garage conversions to ADUs or JADUs under state law. Detached garage ADUs are ministerial. Replacement parking is no longer required under California AB 68 and updated ADU rules.

Sunnyvale allows ADUs and JADUs on single-family and multifamily lots under California Government Code 65852.2 plus AB 68, 881, and SB 13. AB 1033 now allows ADUs to be sold as separate condos.

Tiny homes on foundations qualify as ADUs in Sunnyvale under state law. Tiny homes on wheels are regulated as RVs and cannot be used as permanent dwellings outside of RV parks or approved JADU setups.

Carports are permitted in Sunnyvale as accessory structures under Municipal Code Chapter 19.38. Residential carports must meet zoning setbacks, height limits, and building permit requirements when over 120 square feet.

Sunnyvale allows backyard sheds up to 120 square feet without a building permit under Municipal Code Chapter 19.38. Sheds must meet setbacks and cannot be used as living space or connected to utilities.

Sunnyvale allows residential recreational fire pits fueled by clean natural gas or propane. Wood-burning outdoor fires are heavily restricted under BAAQMD Regulation 6 Rule 3 and Sunnyvale Fire Code.

Open burning of yard waste, trash, and construction debris is prohibited in Sunnyvale. BAAQMD Regulation 5 bans agricultural and residential burning across the Bay Area including Santa Clara County.

Sunnyvale follows Valley Water drought stage rules and enforces permanent outdoor watering limits. AB 1572 bans irrigating non-functional turf at commercial and HOA sites starting in 2027.

Sunnyvale has a strong Heritage Tree Ordinance under Municipal Code Chapter 19.94 requiring permits to trim large trees. Routine pruning is allowed but heavy cuts on protected trees need city approval.

Removing any heritage tree in Sunnyvale requires a permit from the city arborist under Municipal Code Chapter 19.94. Unauthorized removal triggers fines up to 10000 dollars plus mandatory replacement.