Los Altos Hills Zoning, Planning & Building Codes

Last reviewed: July 3, 2026

Overview

Los Altos Hills regulates land use principally through Title 10 — Zoning and Site Development of the Los Altos Hills Code (the town’s Zoning Code), which organizes districts, objective development formulas and a permit/review system intended to preserve the town’s rural, low‑density character. Key local districts are the Residential‑Agricultural (R‑A) and Open Space Reserve (OSR) districts; most rules about setbacks, height, floor area and lot configuration are in Article 5 of Title 10 and the accompanying site‑development provisions. Readers should use this page as the single‑page orientation to the town’s code structure, the district framework, citywide standards (setbacks/height/MDA/MFA/parking), discretionary vs. ministerial review, and how state housing laws (ADU, SB 9) are implemented locally. See the town’s zoning menu for topic pages on zoning, land use and development standards for deeper dives.

How Los Altos Hills's code is organized

• The zoning rules are codified under Title 10. The code is structured with Articles and numbered code sections (for example, district establishment is in § 10-1.301). The zoning map and district boundaries are adopted by reference into the code (§ 10-1.302) .
• Zoning (use districts, nonconforming rules, area/coverage/height/setback limits) is in the Chapter 1 articles of Title 10 (many sections begin with 10‑1.xxx); site development, permitting procedures, administration and enforcement are largely in Chapter 2 articles (sections beginning 10‑2.xxx) such as the permit rules at § 10-2.301 and administrative procedures at § 10-2.1301 .
• Appeals, variances, conditional use/conditional development permit standards and findings are centralized in the Article 10 cluster (e.g., § 10-1.1007 and § 10-1.1009) and identify who acts on which requests and the appeal deadlines .

Zoning district families

• The Code establishes two primary district families: Residential‑Agricultural (R‑A) and Open Space Reserve (OSR). The establishment of these districts is in § 10-1.301 and the zoning map rules are in § 10-1.302–10-1.303 .
  • R‑A (Residential‑Agricultural): permits primary dwellings, limited institutional uses, agriculture and other low‑density uses; conditional uses such as some community facilities require Planning Commission approval (see § 10-1.701 and related R‑A rules in Article 7) .
  • OSR (Open Space Reserve): restricts uses to open‑space, forestry and agricultural uses and subjects accessory structures to stringent siting/height limits (see § 10-1.801–10-1.804) .
• Special local area rules: the Upper Neary Quarry Lands have their own regulations (Article 9, § 10-1.901–10-1.902) that impose minimum lot sizes, conservation easement requirements and siting/height limits specific to that ~300‑acre area .
• If land is unclassified on the map, the Code defaults it into R‑A until otherwise rezoned (§ 10-1.307) .

Citywide development standards

This section summarizes the primary objective standards and where to find them in the Code.

• Lot / parcel size and development formulas
  • Minimum parcel size and the town’s development formulas (Maximum Development Area — MDA — and Maximum Floor Area — MFA) are set out in § 10-1.501 and § 10-1.502; the MDA/MFA are computed using net acres, average slope and the lot unit factor, and those formulas determine how much of a lot can be developed (§ 10-1.502) .
• Setbacks and height
  • The town’s general height rules, structure measurement method, and the discretionary authority to reduce maximum heights on visually sensitive sites are in § 10-1.504, and setback regulations are in § 10-1.505 (these are the base standards the Site Development Authority applies) .
  • Example local mandatory setback guidance (used for ADU siting) lists a 40‑foot front setback measured from the primary street in some contexts, and 30‑foot standards in others; the code also allows the Planning Commission or Site Development Authority to increase setbacks where necessary to reduce bulk/visual impacts (§ 10-1.504–10-1.505) .
• Floor area / coverage
  • MFA and impervious coverage limits are governed through Article 5/MDA formulas; the Code also caps combined ground coverage of structures, roadways and parking at 40% of the lot net area for certain conditional uses (§ 10-1.502 and related R‑A rules) .
• Parking
  • Residential parking requirements are unusually high compared with many cities: each new primary dwelling must provide surfaced off‑street parking for a minimum of four cars, including at least two covered spaces for each new primary dwelling (§ 10-1.601) — accessory dwelling unit parking is handled separately under the ADU article (§ 10-1.601 and Article 14) .
  • For conditional uses the Code requires parking sufficient for maximum foreseeable assemblies and confirms parking and impervious coverage limits in the R‑A provisions (see § 10-1.701 and the off‑street parking article) .
• Fences, grading, ridgeline protection, landscaping and driveway standards
  • Rules intended to protect the town’s rural character (fence/wall height, grading thresholds, ridgeline protection and the Master Path Plan implementation) are found in the Site Development Chapter and Article 5 provisions (see § 10-2.102, § 10-1.507, and related sections) .

For details and illustrative formulas, consult the town’s development standards page and the code sections above.

Specific plans & overlays

• The code contains area‑specific rules rather than a long menu of mixed‑use specific plans: the Upper Neary Quarry Lands regulations are the clearest area plan in the Zoning Code (see § 10-1.901–10-1.902) and impose 10‑acre minimum net lot sizes, limitations on siting on ridgelines, and conservation easement requirements for that special area .
• The code does not show a general “overlay districts” list in the retrieved materials; users should consult the town’s overlay districts menu or confirm with the Planning Department if you expect historic, hillsides, or other overlays — specific overlay designations (beyond OSR and the Quarry Lands rules) were not evident in the retrieved Title 10 extracts (Not found in retrieved materials) .
• Short‑term rental rules are codified as a separate Article (Article 12, § 10-1.1201–10-1.1207) and require conditional short‑term rental permits and operational standards (see § 10-1.1203–10-1.1205) .

Building permits & review

• Permit types and paths
  • Basic zoning and building review flows: a zoning permit is required before a building permit; the Code states that neither a building permit nor a site development permit shall be issued until a zoning permit is obtained (§ 10-1.310) .
  • Site Development Permits and Zoning Permits: ministerial Administrative Review items and full site development applications are defined in § 10-2.301 and the site development administration rules are in § 10-2.1301–10-2.1309 (application contents, submittal materials, inspection and expiration rules) .
• Review bodies, discretionary review and fast‑track options
  • The permit authority is tiered: the Planning Director/Staff Committee handles limited variances and smaller adjustments; the Planning Commission hears conditional development permits, larger variances and more constrained lot situations; appeals from Planning Commission actions go to the City Council (see § 10-1.1007 and § 10-1.1009) .
  • The Code includes a fast‑track process administered by the Planning Director for some projects that conform to objective standards and do not require variances (§ 10-2.1305.1) — but certain categories (e.g., estate homes) are expressly ineligible for fast‑track review (§ 10-1.508) .
  • The Site Development Authority limits discretionary review to issues tied to the General Plan, Zoning and Site Development Codes and generally does not re‑write detailed architectural design features (§ 10-2.1305) .
• Variances, conditional permits, and appeals
  • The code details variance thresholds (what the Staff Committee vs. the Planning Commission hears) — for example, staff may approve small MDA or MFA exceedances while the Planning Commission handles larger requests; findings required for conditional permits and variances are in § 10-1.1007 and public hearing/notice rules are in § 10-1.1005 and § 10-1.1009 .

For procedural orientation see the town’s design review and variances and exceptions pages and consult the cited code sections above.

State housing law in Los Altos Hills

Los Altos Hills incorporates state housing requirements where the Code or recent ordinances update local provisions. Below is a practical summary of how a few major state laws are reflected locally.

• Accessory Dwelling Units (ADUs & JADUs)
  • Local ADU rules are in Article 14 of Title 10 (notably § 10-1.1403–10-1.1404). The Code allows an ADU up to 800 sq ft beyond the town’s MFA in some cases, establishes 4‑ft side/rear setbacks as the local minimum for ADUs, and caps detached ADU height at 16 feet (18 feet under limited transit‑adjacent conditions) — see § 10-1.1403–10-1.1404 for the local program and parking exceptions for ADUs (§ 10-1.1404(g)) .
  • The town’s ADU provisions explicitly reference (and align with) state constraints on local ADU regulation; the statewide ADU standards and limitations that restrict local size/setback/parking rules are summarized in the town files and reflect state law (see the uploaded California ADU handbook for statewide requirements) . For the town’s procedural ADU requirements consult ADUs.
• SB 9 (two‑unit and lot split rules)
  • Los Altos Hills added an SB 9 implementation article (Article 15) with ministerial objective standards. The Code permits SB 9 units consistent with state law, defines allowed unit counts, caps an SB 9 unit at 900 sq ft and sets a 16 ft height limit for such units (see § 10-1.1504–10-1.1506). The Code also handles lot split configuration, panhandle/driveway access rules and fee obligations for SB 9 lot splits (§ 10-1.1504–10-1.1506) .
  • SB 9 units are subject to objective building and grading limits and are reviewed ministerially without discretionary public hearings where the objective standards are met (§ 10-1.1506) .
• Density bonus, rent control and other state housing programs
  • I did not find a local density‑bonus implementation section or any local rent‑control ordinance in the retrieved Title 10 materials (Not found in retrieved materials). Verify with the Planning Department or City Clerk for any recent Council actions outside Title 10 that implement density bonus rules or local rent regulations (Amendments are governed under § 10-1.1013) .

Summary table (where to look in the Code)

• Districts / zoning map: § 10-1.301 – 10-1.307
• Lot size / MDA / MFA: § 10-1.501 – 10-1.502
• Height / setbacks / fences: § 10-1.504 – 10-1.507
• Off‑street parking: § 10-1.601 – 10-1.602
• ADUs (Article 14): § 10-1.1403 – 10-1.1407
• SB 9 (Article 15): § 10-1.1504 – 10-1.1506
• Permits, administration & appeals: § 10-2.301, § 10-2.1301 – 10-2.1309, § 10-1.1007 – 10-1.1009

Source References

• Los Altos Hills Code (Title 10 — Zoning and Site Development), eCode360 (town codified ordinance) — see the Table of Contents and the cited sections throughout this overview; e.g., § 10-1.301 (districts), § 10-1.502 (development area), § 10-1.504–10-1.505 (height/setbacks), § 10-1.601 (parking), § 10-1.1403–10-1.1404 (ADU rules), § 10-1.1504–10-1.1506 (SB 9) .
• Los Altos Hills Site Development and permit administration provisions (Title 10, Chapter 2; permits & fast‑track): § 10-2.301, § 10-2.1305.1, § 10-2.1307 .
• 2025 California ADU handbook (state ADU rules summary used to interpret ADU limits and state constraints) — uploaded file summarizing state ADU law and impacts on local regulation .