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

California Civil Code 841 (Good Neighbor Fence Act) presumes equal cost-sharing between adjoining property owners, and Palo Alto requires 30-day written notice before building or replacing a shared fence.

Palo Alto enforces California Health and Safety Code 115920 requiring pool barriers at least 60 inches tall with self-closing, self-latching gates for all residential pools and spas.

Palo Alto requires a building permit for fences over 7 feet tall or any retaining-wall combination exceeding 4 feet; fences at or under 6 feet generally do not need a permit.

Palo Alto requires a building permit for any retaining wall over 3 feet tall or supporting a surcharge, with engineered drawings required above 4 feet under PAMC Title 16.

Palo Alto limits fences to 6 feet in rear and side yards and 3 feet in front yards under PAMC 18.40.090, with sight-triangle rules at corners.

Above-ground pools deeper than 18 inches require a Palo Alto building permit and must meet the same safety-barrier requirements as in-ground pools.

Palo Alto enforces California Health and Safety Code 115922, requiring at least two drowning-prevention safety features such as an enclosure at least 60 inches high.

Building and plumbing permits are required for any new in-ground or above-ground pool holding over 18 inches of water, with plan check by Palo Alto Development Services.

Hot tubs and spas in Palo Alto require permits when over 18 inches of water and must have a locking, listed safety cover under California H and S 115921.

In addition to fencing, Palo Alto pools must have anti-entrapment drain covers under the Virginia Graeme Baker Act and GFCI-protected electrical equipment.

Palo Alto allows conversion of an existing garage or accessory structure to an ADU or JADU under PAMC §18.42.040 and California Government Code §65852.2. No replacement parking is required. A converted accessory structure may expand by up to 150 sq ft to accommodate ingress and egress.

Palo Alto regulates ADUs and JADUs under Palo Alto Municipal Code §18.42.040 (with updated provisions in PAMC Chapter 18.09). Attached ADUs are capped at 850 sq ft for studio/one-bedroom or 1,000 sq ft for two-or-more bedrooms, and may not exceed 50% of the primary dwelling. JADUs are limited to 500 sq ft within the existing single-family dwelling.

Carports in Palo Alto are regulated as accessory structures under PAMC Title 18. They require building permits, must meet setbacks and height limits, and typically cannot be enclosed without converting to a garage.

Detached sheds up to 120 square feet and under 12 feet tall are exempt from building permits in Palo Alto, but zoning setback rules still apply. Larger sheds require permits.

Tiny homes on foundations are permitted in Palo Alto as ADUs when they meet the CA Residential Code. Movable tiny homes on wheels are generally not allowed as full-time dwellings.

Open burning of yard waste, trash, or land-clearing debris is prohibited in Palo Alto. Only small recreational wood or charcoal fires in approved devices are allowed, and those are banned on Spare-the-Air days.

Palo Alto allows gas and propane fire pits on residential property. Wood-burning recreational fires are restricted on Spare-the-Air days and prohibited in Very High Fire Hazard Severity Zones in the western foothills.

Palo Alto enforces permanent water waste rules and activates drought-stage restrictions set by Valley Water and the State Water Board. AB 1572 bans potable irrigation of non-functional commercial turf.

Palo Alto has one of the strictest tree ordinances in California. Heritage, protected, and street trees may not be pruned more than 25 percent without a permit from the Urban Forestry program under PAMC Chapter 8.04.

Removing protected or street trees in Palo Alto requires a permit. Heritage trees and regulated oaks can only be removed with findings of hazard, disease, or undue hardship, and replacement trees are typically required.