Los Altos Hills · Building on your lot
Building on your lot in Los Altos Hills
Los Altos Hills sets fence, wall and gate heights by distance from the road centerline, and every new or replaced fence needs a zoning or site development permit. Accessory uses and structures in the R-A zone have their own section.
Key points
- Fence height: Fences and walls on property lines or in setbacks not next to a road are limited to 6 feet.
- Accessory structures: The code has a section on accessory uses and structures in the R-A zone (§ 10-1.702).
Each rule below is marked Los Altos Hills code or CA state law and links to the section it comes from (checked October 2026). General information, not legal advice.
Fences and walls
Los Altos Hills code Fences and walls on property lines or in setbacks not next to a road are limited to 6 feet.
All 9 Los Altos Hills rules on fences and walls, with the code text →
Lot splits under SB 9
Los Altos Hills code 2 lots of about equal area; neither smaller than 40% of the original lot's area. At most 900 square feet.
All 22 Los Altos Hills rules on lot splits under SB 9, with the code text →
Solar panels and EV chargers
Los Altos Hills code Apply by email, or at the Building Division front counter during regular business hours. 1 inspection, scheduled within 3 business days of a request.
All 5 Los Altos Hills rules on solar panels and EV chargers, with the code text →
Tree removal
Los Altos Hills code These trees need not be replaced if a certified arborist confirms in writing they are dead or beyond treatment. Removal allowed only when needed for roads, structures in proposed rights-of-way, or rough grading of driveways or parking areas.
All 4 Los Altos Hills rules on tree removal, with the code text →
Pets, chickens and bees
Los Altos Hills code Give written notice to the City Manager within 5 days after the move begins. No more than 3 dogs.
All 5 Los Altos Hills rules on pets, chickens and bees, with the code text →
Building in a flood zone
| Floodplain permit |
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|---|---|
| Building in a floodway |
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| Height of the lowest floor |
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Grading and erosion control
| Steepest cut or fill slope |
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|---|---|
| Rainy-season limits |
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Building on a hillside
Los Altos Hills code Grading into steep hillsides may not exceed 10% of the minimum contiguous buildable area. Buildings may be no taller than 19 feet.
All 4 Los Altos Hills rules on building on a hillside, with the code text →
Noise and construction hours
| Noise limit at homes |
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|---|
Outdoor lighting
| Shielding |
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|---|
Family child care homes
| Zoning | A small or large family child care home is a residential use and a use by right under all local ordinances, including zoning |
|---|---|
| Business license or fee | A city or county may not charge a business license, fee or tax to run a family child care home |
| 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 |
| Small home | Up to eight children, counting the provider's own children under 10 who live there |
| Large home | 7 to 14 children, counting the provider's own children under 10 who live there |
Parking spaces required for homes
| Garage and covered spaces |
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|---|---|
| Spaces for a single-family home |
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Home alarm permits and false alarms
| False alarm fees |
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|---|---|
| False alarms before a fee |
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Signs on homes
Los Altos Hills code Up to 6 square feet in total area. Up to 6 square feet.
All 5 Los Altos Hills rules on signs on homes, with the code text →
Trash and recycling carts
Los Altos Hills code The owner of an occupied premises must subscribe to and pay for at least the minimum universal service. Remove containers from the collection station within 24 hours after collection.
All 3 Los Altos Hills rules on trash and recycling carts, with the code text →
Historic homes
| Changing a historic home |
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|---|---|
| Demolishing an older or historic home |
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Other Los Altos Hills rules on this
Los Altos Hills's code also has these chapters. We have not summarized their values on this page yet; read them in the library.
- Accessory uses and structures, R-A zone (§ 10-1.702)
- Lighting for home pools and spas (§ 10-2.1003)
- Draining a pool to the sewer (§ 6-4.444)
Who this affects
Frequently asked questions
How big can a shed or accessory building be in Los Altos Hills?
The code has a section on accessory uses and structures in the R-A zone (§ 10-1.702). Los Altos Hills also has a related rule: Accessory uses and structures, R-A zone (§ 10-1.702).
What are the rules for building in a Los Altos Hills flood zone?
Los Altos Hills's code: You need a development permit before any construction or other development begins. (Applies within any special flood hazard area.) (§ 7-4.401); The lowest floor must be at least as high above the highest adjacent ground as the flood map depth number. (New or substantially improved homes in an AO zone where the flood map shows a depth number.) (§ 7-4.501).
What are the grading rules in Los Altos Hills?
Los Altos Hills's code: From October 1st to April 30th, the City Engineer may restrict grading. (§ 10-2.404); Fill slopes may be no steeper than 2 horizontal to 1 vertical. (Applies to fill.) (§ 10-2.406).
What are the noise rules and construction hours in Los Altos Hills?
Los Altos Hills's code: Noise may not exceed 50 dBA in daytime or 40 dBA at night. (Fixed noise sources, measured at or beyond the property line; day is 8:00 a.m. weekdays, 9:00 a.m. weekends and holidays, to 7:00 p.m.) (§ 5-2.02); Noise may not exceed 50 dBA in daytime or 40 dBA at night. (Machines, tools or appliances, at or beyond the property line; day is 8:00 a.m. weekdays, 9:00 a.m. weekends and holidays, to 7:00 p.m.) (§ 5-2.02).
What are the outdoor lighting rules for homes in Los Altos Hills?
Los Altos Hills's code: Shield outdoor lights so the source is not directly visible off-site; no more than 2 lights in setbacks. (§ 10-2.1005); Pool and spa lights may cast no direct light beyond the pool or spa area. (Swimming pools and spas.) (§ 10-2.1003).
Can I run a family child care home in Los Altos Hills?
California law sets this for every city, including Los Altos Hills: 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)).
How many parking spaces does a home need in Los Altos Hills?
Los Altos Hills's code: Each parking space must be at least 10 feet wide and 20 feet long. (Required residential parking spaces.) (§ 10-1.601); Unobstructed vehicular access must be available at all times. (All required residential parking spaces.) (§ 10-1.601).
Do I need a permit for a home alarm in Los Altos Hills?
Los Altos Hills's code: A service charge applies. The amount is set by resolution. (Third false alarm and each later false alarm in a 12-month alarm period (July 1 to June 30).) (§ 4-6.02); No service charge until the third false alarm in each 12-month alarm period. (The alarm period runs July 1 to June 30.) (§ 4-6.02).
What rules apply to a historic home in Los Altos Hills?
Los Altos Hills's code: A landmark alteration permit from the City Council is required. (Any material change in exterior appearance of a designated landmark: alteration, construction, relocation or exterior painting.) (§ 11-1.09); A landmark alteration permit from the City Council is required. (Demolition of a designated landmark.) (§ 11-1.09).
General information, not legal advice.
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