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

Retaining walls up to four feet tall measured from the bottom of the footing to the top of the wall generally do not require a permit in Walnut Creek, while walls over four feet or supporting surcharge loads require a building permit with engineered design.

Hedges and dense landscaping in Walnut Creek are treated as fences when used as boundary screening and are subject to the same height limits as solid fences — six feet in side and rear yards and three and a half feet in front-yard setbacks and corner sight triangles.

Swimming pool barriers in Walnut Creek must comply with California Health & Safety Code Sections 115920-115929, requiring a minimum 60-inch-high enclosure with self-closing and self-latching gates; pools built after 2007 must include at least two of seven specified drowning-prevention safety features.

Walnut Creek fences are generally limited to six feet in rear and side yards and three and a half feet in front yards and street-side setbacks; corner lot visibility triangles require lower heights to preserve sight lines for drivers and pedestrians.

All Walnut Creek pools and spas must have anti-entrapment drain covers meeting ANSI/APSP-16 and the federal Virginia Graeme Baker Pool and Spa Safety Act. Public pools and spas require dual main drains or an approved unblockable cover system. Older single-drain pools must be retrofitted as part of any permitted renovation.

Walnut Creek pool barriers must comply with California's Swimming Pool Safety Act (HSC §115920–115929), requiring a minimum 60-inch enclosure with self-closing, self-latching gates and non-climbable features. Pools permitted after 2007 must also include at least two secondary safety features from the state-approved list.

Walnut Creek requires a building permit for above-ground swimming pools unless the prefabricated pool's walls are 24 inches or less and capacity is 5,000 gallons or less. Pools must be enclosed by a minimum 54-inch fence with a self-latching gate, and the California Pool Safety Act (Health & Safety Code 115921 et seq., SB 442) requires at least two of seven approved drowning-prevention features at any new or remodeled residential pool.

Detached garages in Walnut Creek are regulated as accessory structures with zoning setbacks typically 3–5 feet from side/rear property lines and height limits around 15 feet. Garage conversions to living space or ADUs are expressly permitted under state law (AB 68) and the city cannot require replacement parking within half a mile of major transit.

Walnut Creek must allow Accessory Dwelling Units (ADUs) and Junior ADUs on all residential lots under California Government Code Section 65852.2, as strengthened by AB 68, AB 881, and SB 13. Permitted detached ADUs up to 800 sq ft require 4-foot side/rear setbacks, no replacement parking within half-mile of transit, and 60-day permit processing.

In Walnut Creek, detached storage sheds under 120 square feet and 12 feet tall are exempt from building permits under the California Building Code, but must still meet zoning setback requirements — typically 3 feet from side and rear property lines and behind the front building setback. Sheds over 120 sq ft require a building permit.

Open burning is effectively prohibited in Walnut Creek. The Contra Costa County Fire Protection District (ConFire) enforces a year-round ban on outdoor residential burning, and the Bay Area Air Quality Management District (BAAQMD) prohibits open burning of landscape waste, garbage, and construction debris under Regulation 5.

Residential fire pits must use gas or manufactured logs per BAAQMD. No wood fires. 25-ft setback from structures required. No use on Spare the Air days. WUI proximity makes compliance important.

Walnut Creek has one of the Bay Area's strongest tree preservation ordinances. Removal of any Protected Tree — including Heritage Trees, native oaks, and trees of significant size on private property — requires a Tree Removal Permit from the Planning Division. Unauthorized removal can result in fines up to $10,000 per tree plus replacement requirements.

Walnut Creek is served by East Bay Municipal Utility District (EBMUD) and Contra Costa Water District (CCWD), both of which enforce permanent statewide water waste prohibitions plus district-specific watering schedules. Outdoor irrigation runoff, hosing hard surfaces, and watering within 48 hours of rain are always prohibited.