Walnut Creek · Building on your lot

Building on your lot in Walnut Creek

Walnut Creek sets its own limits on fences, accessory structures and home businesses. Taller fences need a minor use permit, and some commercial uses, such as auto repair, may not run from a home.

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Key points

Fence height: Walnut Creek limits residential fences to 3 feet in the required front setback and 7 feet in interior side, rear and corner side setbacks.
Accessory structures: Walnut Creek rear-yard accessory structures: at most 9 feet; total roof area 230 sq ft or 20% of the rear yard, whichever is less.
Home businesses: Walnut Creek limits a home business to 20% of the home's floor area and two persons, who must be residents.

Each rule below is marked Walnut Creek code or CA state law and links to the section it comes from (checked October 2026). General information, not legal advice.

Fences and walls

Walnut Creek code Walnut Creek limits residential fences to 3 feet in the required front setback and 7 feet in interior side, rear and corner side setbacks.

All 6 Walnut Creek rules on fences and walls, with the code text →

Sheds, garages and other accessory structures

Walnut Creek code Walnut Creek rear-yard accessory structures: at most 9 feet; total roof area 230 sq ft or 20% of the rear yard, whichever is less.

All 10 Walnut Creek rules on sheds, garages and other accessory structures, with the code text →

Running a business from home

Walnut Creek code Walnut Creek limits a home business to 20% of the home's floor area and two persons, who must be residents.

All 9 Walnut Creek rules on running a business from home, with the code text →

Lot splits under SB 9

Walnut Creek code No new lot may be smaller than 40% of the existing lot's area. Inclusionary housing rules do not apply to units up to 850 square feet.

All 12 Walnut Creek rules on lot splits under SB 9, with the code text →

RV and boat parking

Walnut Creek code No street parking from 2:00 a.m. to 6:00 a.m. without a Chief of Police permit. A free permit for 2 back-to-back 2:00 a.m. to 6:00 a.m. periods before and after a trip.

All 3 Walnut Creek rules on RV and boat parking, with the code text →

Solar panels and EV chargers

Walnut Creek code Expedited, nondiscretionary administrative review; apply over the counter, by mail or electronically. Approved administratively when complete and meeting local, State and federal health and safety requirements.

All 4 Walnut Creek rules on solar panels and EV chargers, with the code text →

Tree removal

Walnut Creek code The Director may give written permission to remove a hazardous tree when immediate action is needed for safety. Yes, a tree removal permit is required.

All 3 Walnut Creek rules on tree removal, with the code text →

Grading and erosion control

Walnut Creek code What Walnut Creek's code adds
Grading without a permit	Digs under 3 feet, 2:1 or flatter; fills up to 50 cubic yards; permitted basement, footing or pool digs. Applies: Fills under 1 foot on ground flatter than 5:1, or under 3 feet, non-structural, not blocking drainage; not in natural drainage channels. § 9-9.02 · code text f. An excavation which is less than three feet in depth and slopes no steeper than two horizontal to one vertical; g. Exploratory excavations under the direction of soil engineers or engineering geologists; h. A fill less than one foot in depth, and placed on natural terrain with a slope flatter than five horizontal to one vertical, or less than three feet in depth, not intended to support structures, which does not exceed fifty cubic yards on any one lot and does not obstruct a drainage course;

Building on a hillside

Walnut Creek code A current preliminary soils and geology report by a registered civil engineer and a registered geologist is required. Natural open space must stay free of grading and structures, except trails, picnic areas, stables and similar amenities.

All 3 Walnut Creek rules on building on a hillside, with the code text →

Noise and construction hours

Walnut Creek code What Walnut Creek's code adds
Construction hours on weekdays	7:00 a.m. to 6:00 p.m. Applies: Weekdays that are not holidays; work needing a building or grading permit; other hours only if set in the permit. § 4-6.203 · code text The erection, construction, demolition, alteration or repair of any building, structure or residence that requires a permit, or the excavation of any earth, fill, streets or highways that requires a grading permit, other than between the hours of 7:00 a.m. and 6:00 p.m. on weekdays which are not holidays, or those precise hours of operation enumerated in individual building and grading permits.
Leaf blowers and equipment	8:00 a.m. to 7:00 p.m. on weekdays; 9:00 a.m. to 7:00 p.m. on weekends and holidays. Applies: Allowed hours for noisy landscaping or home upkeep tools (hammers, blowers, trimmers, mowers, chainsaws). § 4-6.203 · code text The use and operation of any noise-creating commercial or residential landscaping or home maintenance equipment or tools including, but not limited to, hammers, blowers, trimmers, mowers, chainsaws, power fans or any engine, the operation of which causes noise due to the explosion of operating gases or fluids, other than between the hours of 8:00 a.m. and 7:00 p.m. on weekdays and 9:00 a.m. and 7:00 p.m. on weekends and holidays.

Family child care homes

CA state law California law
Zoning	A small or large family child care home is a residential use and a use by right under all local ordinances, including zoning Health & Safety Code § 1597.45(a)
Business license or fee	A city or county may not charge a business license, fee or tax to run a family child care home Health & Safety Code § 1597.45(b)
Local rules	Local limits on height, setbacks, lot size, health and safety must be the same as for every other home in the same zone Health & Safety Code § 1597.45(e)
Small home	Up to eight children, counting the provider's own children under 10 who live there Health & Safety Code § 1596.78(c)
Large home	7 to 14 children, counting the provider's own children under 10 who live there Health & Safety Code § 1596.78(b)

Affordable units in new housing (inclusionary)

Walnut Creek code Accessory dwelling units are exempt. Urban lot splits are exempt.

All 7 Walnut Creek rules on affordable units in new housing (inclusionary), with the code text →

Home alarm permits and false alarms

Walnut Creek code What Walnut Creek's code adds
Alarm permit	Required. § 3-9.03 · code text No alarm user shall operate, or cause to be operated, an alarm system at its alarm site without a valid alarm permit issued by the alarm administrator. Required; no charge for permit or renewal. Applies: Residential alarm site. § 3-9.03 · code text There is no charge for a permit or permit renewal for a residential alarm site.
When a permit can be revoked	Exceeding 5 false dispatches in a 12 month period. § 3-9.10 · code text the permit holder has exceed five false dispatches in a 12 month period. 2 additional false alarm dispatches within 60 days. Applies: After the alarm permit is reinstated. § 3-9.10 · code text the alarm administrator may revoke the alarm permit if it is determined that two additional false alarm dispatches occur within 60 days after the reinstatement date.

Signs on homes

Walnut Creek code Not earlier than 90 days before the event. Remove within 7 days after the event.

All 13 Walnut Creek rules on signs on homes, with the code text →

Other Walnut Creek rules on this

Walnut Creek's code also has these chapters. We have not summarized their values on this page yet; read them in the library.

Pets, chickens and other animals at home (§ 10-2.3.108)
Pools not allowed in the front yard (§ 10-2.3.112)
Building in a flood hazard area (Ch. 9-12)
Traffic impact fee (Ch. 10-5)

Who this affects

HomeownersContractorsDesigners

Frequently asked questions

What are the grading rules in Walnut Creek?

Walnut Creek's code: Digs under 3 feet, 2:1 or flatter; fills up to 50 cubic yards; permitted basement, footing or pool digs. (Fills under 1 foot on ground flatter than 5:1, or under 3 feet, non-structural, not blocking drainage; not in natural drainage channels.) (§ 9-9.02).

What are the noise rules and construction hours in Walnut Creek?

Walnut Creek's code: 7:00 a.m. to 6:00 p.m. (Weekdays that are not holidays; work needing a building or grading permit; other hours only if set in the permit.) (§ 4-6.203); 8:00 a.m. to 7:00 p.m. on weekdays; 9:00 a.m. to 7:00 p.m. on weekends and holidays. (Allowed hours for noisy landscaping or home upkeep tools (hammers, blowers, trimmers, mowers, chainsaws).) (§ 4-6.203).

Can I run a family child care home in Walnut Creek?

California law sets this for every city, including Walnut Creek: Zoning: A small or large family child care home is a residential use and a use by right under all local ordinances, including zoning (Health & Safety Code § 1597.45(a)); Business license or fee: A city or county may not charge a business license, fee or tax to run a family child care home (Health & Safety Code § 1597.45(b)); Local rules: Local limits on height, setbacks, lot size, health and safety must be the same as for every other home in the same zone (Health & Safety Code § 1597.45(e)); Small home: Up to eight children, counting the provider's own children under 10 who live there (Health & Safety Code § 1596.78(c)); Large home: 7 to 14 children, counting the provider's own children under 10 who live there (Health & Safety Code § 1596.78(b)).

Do I need a permit for a home alarm in Walnut Creek?

Walnut Creek's code: Required. (§ 3-9.03); Required; no charge for permit or renewal. (Residential alarm site.) (§ 3-9.03).

General information, not legal advice.

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