Local zoning · Los Altos Hills

Los Altos Hills — Design Review

Q: What can I build on an R‑A lot in Los Altos Hills?

The Residential‑Agricultural (R‑A) district allows primary dwellings , compatible agricultural uses, employee/farmworker housing, and similar uses; lot‑specific area/coverage, setbacks and parking rules apply (see § 10-1.701 and Article 5 cross‑references) — .

Q: Where are the objective design standards the Site Development Authority uses?

The code references the Town’s Objective Design Standards/User Guide in the Site Development chapter, but the User Guide text itself was not present in the retrieved file excerpts. Verify and request the Town’s Objective Design Standards User Guide from Planning — Not found in retrieved materials (Verify with the jurisdiction) — .

Design Review under the Los Altos Hills local zoning and planning code, with the controlling citations.

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Last reviewed: July 2, 2026

Overview

Los Altos Hills implements design review primarily through its Title 10 site development and zoning permit processes rather than a standalone “design review board.” Projects that meet the Town’s site-development thresholds go through the Site Development Authority (Staff Committee, Community Development Director, Planning Commission, or City Council depending on referral) under the Site Development chapter; objective design controls apply to specific categories (for example, ADUs and SB 9 units). Key procedures and limits are in § 10-2.301, § 10-2.1303–10-2.1305.1, and ADU/SB 9 articles — .

Note: this page explains only what the Los Altos Hills zoning / planning ordinance says about design-review-type controls. For building-code (Title 24) compliance see the California Building Standards Code — California Building Standards Code.

How Los Altos Hills handles “design review” in the code

The Town’s design-focused review is embedded in the Site Development Permit / Zoning Permit system. Thresholds that trigger a site development permit are listed in § 10-2.301 — .
The application content and technical materials required (plot plans, elevations, grading, landscape plans, soils/geologic reports, story poles where applicable) are set out in § 10-2.1303 and the application/referral process is in § 10-2.1304 — .
The Site Development Authority (the Town’s permitting body for site development) reviews conformance to the Municipal Code, General Plan, and adopted objective standards and may refer plans to standing committees; but it may not alter or regulate purely stylistic architectural details (architectural style, chimneys, window treatment, skylights) — § 10-2.1305(e) — .
Certain categories are explicitly handled ministerially with objective design rules rather than discretionary design review: Accessory Dwelling Units (ADUs) are reviewed ministerially with objective design requirements in § 10-1.1403–10-1.1405, and SB 9 units are treated similarly in § 10-1.1506 — .
Fast-track eligibility and public hearing rules for new residences and other site development applications are in § 10-2.1305.1 and related hearing/appeal timing rules are in § 10-1.1008–10-1.1009 — .

Practical implication: if your project crosses the numeric thresholds in § 10-2.301 you should plan for a Site Development review (notice, committee review, possible hearing). If the project is an ADU or SB 9 unit, check their objective design subsections because those are ministerial — .

District-by-district (where design review / site development rules matter)

Below are the principal districts in the Title 10 code where design-review-type controls and site-development permits commonly apply. Each subsection shows purpose, typical permitted uses, key dimensional guidance, and where design review/site development rules apply.

Residential‑Agricultural (R‑A)

Purpose & where it applies: The R‑A district is the Town’s predominant residential zone for larger lots that retains semi‑rural character; see § 10-1.701 — .
Typical permitted uses: primary dwellings, compatible agricultural uses, employee/farmworker housing, residential care facilities, transitional/supportive housing where licensed — § 10-1.701 — .
Key dimensional standards (decision‑relevant): area/coverage, height, and setbacks for R‑A are applied per Article 5 (see § 10-1.704 for cross‑reference); off‑street parking for new primary dwellings requires minimum four spaces including two covered for each new primary dwelling (dimensions 10' × 20') — § 10-1.704 and § 10-1.601 — .
Where design/site development applies: most new residences and large additions on R‑A parcels will trigger a Site Development permit when thresholds in § 10-2.301 are met; landscaping and screening requirements are enforced by the Site Development Authority — .

Open Space Reserve (OSR)

Purpose & where it applies: OSR protects agricultural/open space and limits structural development; see § 10-1.801–10-1.803 — .
Typical permitted uses: agricultural uses, forest preserves, and other open‑space uses; accessory structures only where necessary for permitted primary uses — § 10-1.801–802 — .
Key dimensional standards: Article 5 standards apply for area, coverage, height, and setbacks — § 10-1.803 — .
Where design/site development applies: site development permits are used to protect ridgelines, natural topography, and minimize grading/vegetation removal; landscaping and species selection are enforced under the Site Development chapter — .

Estate Home rules (special subcategory)

Purpose: estate homes (projects with ≥ 10,000 sq ft floor area) have special, stricter setbacks/height rules to protect rural character — § 10-1.508 — .
Typical controls: front setback starts at 44 ft and grows with size; side/rear setbacks start at 33 ft (see table in § 10-1.508). Maximum overall building height is capped at 35 ft except where additional limitations apply — § 10-1.508 — .
Where design/site development applies: estate home projects are ineligible for fast-track and are subject to Site Development Permit and Planning Commission review with possible additional landscape screening conditions — § 10-1.508 — .

Upper Neary Quarry Lands (special plan area)

Purpose & where it applies: special article covering the Upper Neary Quarry Lands with bespoke constraints (lot sizing, ridgeline siting restrictions) — § 10-1.901–10-1.902 — .
Where design/site development applies: development area and floor area limits are expressly tied to R‑A provisions; Site Development review enforces conservation easements and placement away from ridgelines — .

Quick reference table — decision‑relevant standards and where they live

What you need to know	Short rule / standard	Code Reference
Site Development permit thresholds (grading, building size, cut/fill, development area)	See triggers for required permit (examples: new structures ≥ 500 sf & >19' high, excavations/fills thresholds, development area limits)	§ 10-2.301 —
Application contents (plans, landscape, soils, elevations)	Plot plan, architectural elevations, landscape plan, soils/geotech, erosion control; may require licensed professionals	§ 10-2.1303–10-2.1304 —
Design/architectural limits for Site Development Authority	Authority enforces code conformance; cannot alter pure architectural style or details (e.g., chimneys, skylights)	§ 10-2.1305(e) —
ADU design — ministerial objective controls	ADUs approved ministerially; detached ADUs must match primary dwelling materials, colors, LRV limits, doors, entrances, lighting limits	§ 10-1.1403–10-1.1405 —
SB 9 units — objective building and design requirements	SB 9 units reviewed ministerially; objective height/grading/separation/material-match rules apply	§ 10-1.1506 —
R‑A permitted primary uses; parking for new primary dwellings	Primary dwellings and compatible agricultural uses; 4 parking spaces minimum (2 covered) for new primary dwellings	§ 10-1.701 and § 10-1.601 —
Estate home setbacks/height (large homes ≥10,000 sf)	Front setback start 44 ft; side/rear start 33 ft; max height 35 ft; landscape screening required	§ 10-1.508 —

Practical guidance and synthesis (plain-English)

If your project is a routine small addition or minor grading below the thresholds in § 10-2.301, it may avoid Site Development review; check the thresholds first — § 10-2.301 — .
Big projects, new residences, major additions, or estate‑scale work will typically require a Site Development permit; the Town will demand site plans, elevations, landscape plans (showing screening), soils/geotech, and may refer to standing committees — § 10-2.1303–10-2.1304 — .
Expect that the Site Development Authority enforces objective compliance with the Municipal Code, General Plan policies, and adopted objective standards; it will not re‑design your chosen architectural style, but it can require reduced height, increased setbacks, or additional landscaping to meet Town goals — § 10-2.1305(e) and § 10-2.1305(f) — .
For ADUs and SB 9 units, the Town provides objective design rules and ministerial review (no discretionary design hearing) — see ADU Article § 10-1.1403–1405 and SB 9 § 10-1.1506 — .
Before you finalize design, review off‑street parking obligations and setback/development‑area limits in Article 5 and 6; parking is enforced in § 10-1.601 and ADU parking rules are in Article 14 — § 10-1.601 and § 10-1.1403 — . (If you need the Town’s exact setbacks, consult Article 5 and the parcel’s zoning designation — Verify with the jurisdiction.)

Useful internal Town resources to read in parallel: the Town’s Development Standards, Parking, Overlay Districts, Landscaping and Screening, and the Town’s zoning overview Los Altos Hills Zoning. Also consult the Town pages on ADUs for ministerial ADU design standards.

Checklist — What an applicant must generally provide for Site Development / design review

Completed Site Development / Zoning permit application form — § 10-2.1303 —
Plot plan with property lines, development area, setbacks, driveway and grading contours — § 10-2.1303 —
Architectural elevations showing all sides, building heights, and materials — § 10-2.1303 —
Grading plans and erosion control plan (if grading triggers) — § 10-2.1303 —
Landscape plans and species list, with screening where required — § 10-2.1303 and § 10-2.809 —
Soils/geotechnical and drainage reports if required — § 10-2.1303 —
Story poles for eligible residence projects / fast‑track eligibility — § 10-2.1305.1 —
Mailing/posting for required notices (500‑ft radius or other specified radius depending on article) — § 10-2.1305 —
For ADUs: confirm compliance with ADU objective design rules (LRV limits, matching materials, entrances) — § 10-1.1404 —

Risks & Ambiguities

Issue	Why it matters	What to verify
Whether a specific element is “design” vs. “code” (architectural style vs. height/setback)	Site Development Authority cannot change pure style but can require changes to height, setbacks, landscaping — misreading could cause a refused permit or unnecessary redesign — § 10-2.1305(e) —	Confirm with Planning staff whether proposed change is a discretionary alteration or a code compliance item.
Exact numeric setbacks/height for a parcel	Article 5 contains the numeric setbacks and height provisions referenced by district articles but the code cross‑references Article 5 rather than repeating numbers — § 10-1.704 —	Look up Article 5 for parcel’s zoning designation or ask the Planning Department to confirm parcel‑specific setback/height.
Objective Design Standards / User Guide text	The Site Development chapter refers to “Objective Design Standards” and the Town’s User Guide; that actual document text was not included in the retrieved file excerpts	Not found in retrieved materials — request the Town’s Objective Design Standards User Guide from Planning (Verify with the jurisdiction).
Ministerial vs discretionary treatment of ADUs / SB9	ADUs and SB9 units are subject to objective ministerial standards in the code (limiting discretionary review) but local objective rules still apply — § 10-1.1404, § 10-1.1506 —	Confirm whether any site‑specific constraints (slope, oak preservation, easements) will still trigger additional review or conditions.
Whether a project can be fast‑tracked	Fast-track is allowed for projects meeting the Fast Track Guide score and other criteria, but certain projects (e.g., estate homes) are ineligible — § 10-2.1305.1 and § 10-1.508 —	Verify fast-track eligibility with Community Development Director before relying on expedited timeline.

Plain-English summary

Los Altos Hills performs design-focused review mainly through its Site Development Permit process: large projects, new homes, and significant grading trigger a site development review with required plans and possible hearings; the Site Development Authority enforces code and objective design standards but does not rewrite architectural style, and ADUs/SB‑9 units are handled ministerially under specific objective rules — § 10-2.301, § 10-2.1303–1305, § 10-1.1404 — .

Source References

Site development permit triggers and exceptions — § 10-2.301 —
Application contents and consultant/referral process — § 10-2.1303–10-2.1304 —
Limitations on architectural/stylistic review by the Site Development Authority — § 10-2.1305(e) —
Fast-track process and story‑pole requirement for residences — § 10-2.1305.1 —
Appeals and effective date timelines — § 10-1.1008–10-1.1009 —
ADU objective design and ministerial approval rules — § 10-1.1403–10-1.1405 —
SB 9 units—objective building/design requirements — § 10-1.1506 —
R‑A permitted uses and related controls — § 10-1.701–10-1.706 —
Estate homes rules (setbacks/height/landscape screening) — § 10-1.508 —
Landscape/landscaping plan requirements referenced by Site Development — § 10-2.809 and landscape sections —

(These citations are to the Los Altos Hills Municipal Code excerpts provided for this analysis. Verify parcel‑specific numeric standards and look up the Town’s Objective Design Standards User Guide when preparing final drawings — Verify with the jurisdiction.)

Sources

Retrieved passages

Los Altos Hills Zoning Code (§ 2) High relevance
Los Altos Hills Zoning Code (§ 1) High relevance
Los Altos Hills Zoning Code (Article 10) High relevance
Los Altos Hills Zoning Code (§ 10-1.1302) High relevance
Los Altos Hills Zoning Code (§ 2) High relevance
CFC § 10 (article if) Medium relevance
Los Altos Hills Zoning Code (§ 10-2.1305.1) Medium relevance
Los Altos Hills Zoning Code (§ 15) Medium relevance
Los Altos Hills Zoning Code (§ 10-1.1305) Medium relevance
Los Altos Hills Zoning Code (§ 10-1.1304) Medium relevance
Los Altos Hills Zoning Code (Section 10-1.505) Medium relevance
Los Altos Hills Zoning Code (chapter and) Medium relevance
Los Altos Hills Zoning Code (§ 10-1.902.) Medium relevance
Los Altos Hills Zoning Code (§ 10-1.1007) Medium relevance
Los Altos Hills Zoning Code (§ 10-1.1404) Medium relevance

Cited sections

Site development permit triggers and exceptions — **§ 10-2.301** — (§ 10-2.301)
Application contents and consultant/referral process — **§ 10-2.1303–10-2.1304** — (§ 10-2.1303)
Limitations on architectural/stylistic review by the Site Development Authority — **§ 10-2.1305(e)** — (§ 10-2.1305)
Fast-track process and story‑pole requirement for residences — **§ 10-2.1305.1** — (§ 10-2.1305.1)
Appeals and effective date timelines — **§ 10-1.1008–10-1.1009** — (§ 10-1.1008)
ADU objective design and ministerial approval rules — **§ 10-1.1403–10-1.1405** — (§ 10-1.1403)
SB 9 units—objective building/design requirements — **§ 10-1.1506** — (§ 10-1.1506)
R‑A permitted uses and related controls — **§ 10-1.701–10-1.706** — (§ 10-1.701)
Estate homes rules (setbacks/height/landscape screening) — **§ 10-1.508** — (§ 10-1.508)
Landscape/landscaping plan requirements referenced by Site Development — **§ 10-2.809** and landscape sections — (§ 10-2.809)
LosAltosHills_ZoningCode.md

Official Los Altos Hills code library

Frequently asked questions

Do I need design review in Los Altos Hills?

If your project crosses a Site Development permit threshold (grading, new structures over numeric thresholds, major additions), it will go through the Town’s site development review process rather than a separate “design review board” — see § 10-2.301 and § 10-2.1303–10-2.1305 — .

What is a Site Development Permit and when is it required?

A Site Development Permit is the zoning/planning approval for projects that exceed the Town’s numeric thresholds (examples: certain grading amounts, structures ≥ 500 sf & >19 ft tall, other triggers listed in § 10-2.301). The application must include plans, elevations, grading, and landscape information as required in § 10-2.1303 — .

Are ADUs subject to discretionary design review in Los Altos Hills?

No. ADUs are reviewed ministerially under objective design rules (materials, color LRV limits, entrance placement, lighting limits). See § 10-1.1403–10-1.1405 for the ADU design requirements — .

What can I build on an R‑A lot in Los Altos Hills?

The Residential‑Agricultural (R‑A) district allows primary dwellings, compatible agricultural uses, employee/farmworker housing, and similar uses; lot‑specific area/coverage, setbacks and parking rules apply (see § 10-1.701 and Article 5 cross‑references) — .

How does the Town treat architectural style vs. objective controls?

The Site Development Authority enforces objective code requirements (setbacks, height, development area, landscape screening). The authority shall not regulate or alter pure architectural features like style, chimneys, window treatment or skylights — § 10-2.1305(e) — .

How long does review take and can I fast‑track?

Timing varies; ministerial ADU approvals have a 60‑day clock for completeness and action in § 10-1.1406, and the Town has a Fast‑Track process for eligible new residences under § 10-2.1305.1. Fast‑track requires meeting the Fast Track Guide score and other criteria — .

What are my appeal options if I disagree with a Site Development decision?

Actions of the Staff Committee or Planning Commission become final after a short appeal period; interested parties may appeal to the Planning Commission (Staff Committee decisions) or to City Council (Planning Commission decisions) within the timelines set in § 10-1.1008–10-1.1009 — .

Where are the objective design standards the Site Development Authority uses?

The code references the Town’s Objective Design Standards/User Guide in the Site Development chapter, but the User Guide text itself was not present in the retrieved file excerpts. Verify and request the Town’s Objective Design Standards User Guide from Planning — Not found in retrieved materials (Verify with the jurisdiction) — .

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