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Los Altos Hills · Building on your lot

Building on a hillside in Los Altos Hills

Los Altos Hills's own rules on building on a hillside, with the code text for every value.

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Each rule below links to the section of the Los Altos Hills Municipal Code it was read from, with the code text one click away (checked October 2026). General information, not legal advice.

What Los Altos Hills's code says

Los Altos Hills code What Los Altos Hills's code adds
Grading and retaining walls
  • Grading into steep hillsides may not exceed 10% of the minimum contiguous buildable area.
    Applies: Grading for vehicle access to the buildable area on steep hillsides.
    § 10-1.1614 · code text
    Such encroachment into steep hillsides shall not exceed an area equal to 10% of the minimum contiguous buildable area.
Height on hillside lots
  • Buildings may be no taller than 19 feet.
    Applies: Buildings or structures on a hilltop.
    § 10-1.1614 · code text
    The maximum height of a building or structure on a hilltop shall not exceed 19 feet.
When hillside rules apply
  • No structures on slopes steeper than 25%.
    § 10-1.1614 · code text
    Structures are prohibited on slopes greater than 25%.
  • Sites with natural slopes over 14% must use Type II foundations: step-on-contour, daylight or pole.
    § 10-2.703 · code text
    Type II foundations—step-on-contour, daylight, pole foundations, or a combination thereof — shall be used on building sites with natural slopes in excess of 14%.

Who this affects

HomeownersContractorsDesigners

Frequently asked questions

What extra rules apply to a hillside lot in Los Altos Hills?

Los Altos Hills's code: No structures on slopes steeper than 25%. (§ 10-1.1614); Grading into steep hillsides may not exceed 10% of the minimum contiguous buildable area. (Grading for vehicle access to the buildable area on steep hillsides.) (§ 10-1.1614).

General information, not legal advice.

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Ask GoCodebook how Los Altos Hills's building on a hillside rules apply to your situation and get an answer that cites the section.

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Los Altos Hills Municipal Code — full text