Los Altos — Development Standards

Last reviewed: July 2, 2026

Overview

This page summarizes the Los Altos municipal zoning development standards that control setbacks, height, lot coverage, density, and floor area across the city's zoning districts. It synthesizes the local code (Title 14) rules district-by-district, highlights decision‑critical numbers, and points you to the code sections you must verify. For general context start at the city's Los Altos zoning & planning overview.

District-by-district breakdown

Notes on citations: each rule below cites the controlling code paragraph (the § symbol) and the underlying file excerpt returned from the Los Altos code. Verify parcel‑specific application with the jurisdiction.

R1-10 (Single‑Family, 10,000 sf lots)

• Purpose / typical uses: single‑family residential lots; accessory structures regulated separately (§ 14.06.010 et seq.) .
• Key dimensional standards:
  • Maximum lot coverage: 35% for structures >6 ft tall (and special limits if one‑story height is ≤20 ft) — § 14.06.060 .
  • Maximum FAR / floor area: formula based on lot size — § 14.06.070 (35% for lots ≤11,000 sf; different formula above) .
  • Setbacks: Front 25 ft; Interior side 1st story 10 ft / 2nd story 17.5 ft; Exterior side 20 ft; Rear 25 ft — § 14.06.080 .
  • Height: max 2 stories or 27 ft, basements not counted; flag lots limited to 1 story / 20 ft; if coverage >30% max height can drop to 20 ft — § 14.06.090 .
  • Daylight plane rules (complex angled plane measured from property lines) apply — § 14.06.100 .
• Practical guidance: expect strict front/second‑story stepbacks and daylight‑plane measurement; verify whether your lot is a “narrow” or flag lot — the code adjusts side yard arithmetic in those cases (§ 14.06.080(E)) .

R1-20 (Larger single‑family)

• Purpose / typical uses: single‑family on larger lots. See § 14.10.010 et seq. .
• Key dimensional standards:
  • Maximum coverage: 25% for structures >6 ft — § 14.10.060 .
  • FAR / floor area: same size‑based formula as R1-10 but with different base values — § 14.10.070 .
  • Setbacks: Front 30 ft; Interior side 1st story 20 ft (25 ft if >22 ft height); 2nd story 25 ft; Rear 35 ft — § 14.10.080 .
  • Lot area & frontage: minimum site area 20,000 sf, frontage, and depth rules — § 14.10.040–050 .

R1‑H (Hillside / restricted single‑family)

• Purpose: larger‑lot hillside residential with greater setbacks and low coverage standards — see § 14.08.010 et seq. .
• Key dimensional standards:
  • Maximum coverage: 25% (for lots ≥15,000 sf; smaller lots follow Chapter 14.06) — § 14.08.060 .
  • FAR: same lot‑size formula as R1 zones — § 14.08.070 .
  • Setbacks: Front 30 ft; Interior side 1st story 20 ft (25 ft if height >22 ft); 2nd story 25 ft; Exterior side 25 ft; Rear 50 ft — § 14.08.080 .
• Practical guidance: steep‑slope and flag‑lot provisions are stricter; administrative extensions for existing encroachments are narrowly allowed (§ 14.08.080(E)) .

R3-5 (Higher‑density multi‑family)

• Purpose / typical uses: multiple‑family/residential up to the R3‑5 density standard — see § 14.18.010 et seq. .
• Key dimensional standards:
  • Maximum coverage: 60% for structures >6 ft — § 14.18.050 .
  • Front yard: 40 ft; side yards: 15 ft (25 ft where abutting street); rear: 30 ft (special buffer where abutting R1‑10) — § 14.18.060–080 .
  • Height: multi‑family residential max 40 ft / 4 stories measured from adjacent natural grade — § 14.18.100 .
• Practical guidance: where R3 abuts R1‑10 expect mandatory fences/walls and evergreen screening in the first 10 ft of the abutting yard (§ 14.18.070–080) .

R3‑1 / R3‑4.5 (Medium‑density and tailored small‑area districts)

• R3‑1: minimum site area 5,100 sf, coverage 65%, front yard 20 ft, side 7.5 ft (corner streets 15 ft), rear 25 ft, height rules and parking reference Chapter 14.74 — see § 14.24.040–100 .
• R3‑4.5: special district to retain small‑area character (Stevens Place / Marshall Court) — min site 7,000 sf, coverage 60%, FAR 55%, tailored setbacks — see § 14.16.030–080 .

OA‑1 and OA‑4.5 (Office/Administrative, mixed‑use)

• Purpose / uses: office‑administrative, residential only, and mixed use as allowed — § 14.34.040 .
• Key dimensional standards:
  • Maximum coverage: 75% of gross lot area (habitable structures only) — § 14.34.060 .
  • Setbacks: front yard min 5 ft (50% landscaped); side yards 5 ft except 25 ft where abutting R1‑10; rear 15 ft (30 ft where abutting R1‑10) — § 14.34.070–090 .
  • Density: residential uses 20–30 units/acre — § 14.34.065 .
• Practical guidance: OA districts allow close‑to‑street building placement but require buffers where adjacent to single‑family neighborhoods — check façade and buffering rules and the overlay district that may modify these standards .

CT (Corridor / El Camino Real standards)

• CT includes detailed façade, step‑back, and adjacency controls for corridors like El Camino Real: e.g., 75% ground‑floor frontage build‑to, upper story stepbacks, façade articulation, and limits where abutting R‑1 — see § 14.50.170 for building placement, massing, and adjacency rules .
• Practical guidance: projects on El Camino Real face both front‑build‑to and upper‑story stepback rules; expect design control and stricter articulation requirements.

PUD, PC and Planned Development standards

• PUD (Planned Unit Development) standards are project‑specific but must be no less rigorous than comparable district rules; PUD/SC (senior), PUD/R, PUD/OA, PUD/C have their own height/density/setback rules and specific nearby‑R1 buffers — see § 14.62.070–090 and § 14.62 series .
• PC (Planned Community): generally applies R1/R3 standards based on lot sizes or cluster rules with special coverage limits (e.g., 20% for cluster subdivisions) — see § 14.56.070 .
• Practical guidance: PUD and PC approvals set project‑level standards (approved by commission/council); check the approved development standards for the specific PUD parcel.

Accessory Dwelling Units (ADUs)

• ADU development is governed by its own chapter (Chapter 14.64): maximum unit counts, objective development standards (setbacks as small as 4 ft side/rear in some cases), coverage and height rules specific to ADU practice, and parking exceptions tied to transit proximity — see § 14.64.080–100 . For ADU development rules see the city's Los Altos ADUs.
• Practical guidance: ADU development often relaxes lot‑coverage/yard limits but remains subject to objective standards and the ADU chapter; check whether your parcel qualifies for parking reductions; see the California ADU law and local ADU chapter for interaction with state rules .

Parking and design control

• Parking requirements live in Chapter 14.74 (referenced repeatedly) and are triggered per‑use; parking location, covered space sizing, and parking structure placement rules are called out in OA and ADU sections — see OA § 14.34.110 and ADU parking rules in § 14.64.090 . For specifics see the city's Los Altos Parking.
• Design review and architectural/site approval are required in many districts; the code mandates design control for PUDs, CT, OA, and other districts with referral to Chapter 14.78 and specific design sections (e.g., CT § 14.50.170) — see the city's Los Altos Design Review page .

Quick reference table — decision‑critical standards

(See the cited sections for full nuance, buffers where OA abuts R1, and footnote exceptions.)

Checklist

• Confirm zoning district for the parcel (e.g., R1‑10, R1‑20, R3‑5, OA‑1) and pull the district chapter in Title 14 — verify applicable § (e.g., § 14.06, § 14.10, § 14.18, § 14.34) .
• Verify minimum site area / frontage and lot‑type exceptions (flag, narrow) for your parcel — e.g., § 14.06.040–060, § 14.10.040 .
• Check maximum lot coverage, FAR/floor area calculation (lot‑size formula where applicable) — see district § references above (e.g., § 14.06.060–070, § 14.16.060) .
• Measure and document front/side/rear setbacks including second‑story setbacks and daylight plane rules (e.g., § 14.06.080, § 14.06.100) .
• Confirm height limits (stories and feet) and any coverage‑triggered height reductions — e.g., § 14.06.090, § 14.18.100 .
• Run parking needs against Chapter 14.74 and district parking notes (OA, ADU exceptions) — see OA § 14.34.110 and ADU § 14.64.090; consult the city's Los Altos Parking page .
• Determine whether design review or architectural/site approval is required (many districts reference Chapter 14.78; CT and PUDs commonly require review) — see CT § 14.50.170 and PUD rules .
• If proposing higher density or concessions, prepare a density bonus/waiver package per § 14.28 and state density bonus law requirements — see § 14.28.050 for submission requirements .
• If seeking relief, use variance procedures (Chapter 14.81) — § 14.81.020 et seq. lists applicability and required findings .

Risks & Ambiguities

Plain‑English Summary

Los Altos zoning (Title 14) controls how big and how tall buildings can be through precise district rules: most single‑family zones (like R1‑10 and R1‑20) set strict setbacks, coverage limits, floor area formulas, and a 27‑ft / 2‑story height cap; multi‑family zones allow higher coverage and taller buildings but require larger buffers where they touch single‑family neighborhoods. Always pull the district § (examples: § 14.06, § 14.10, § 14.18, § 14.34) and confirm parcel specifics.

Source References

• Los Altos Municipal Code, Title 14 excerpts used in this page: § 14.06.060–110, § 14.06.080, § 14.06.090, § 14.06.100 (R1‑10 standards) .
• § 14.10.060–080 (R1‑20 standards) .
• § 14.08.060–080 (R1‑H standards) .
• § 14.18.050–100 (R3‑5 standards) .
• § 14.16.050–080 (R3‑4.5 district) .
• § 14.34.060–110 (OA‑1 / OA‑4.5 standards) .
• § 14.62 (PUD standards) and § 14.56.070 (PC) for project/site‑specific standards .
• § 14.50.170 (CT corridor design controls) .
• Chapter 14.64 (ADU standards; objective standards and unit limits) — see § 14.64.080–100 .
• Density bonus procedures and application requirements § 14.28.050 .
• Variances and exceptions: Chapter 14.81 (variance applicability and findings) — § 14.81.020–040 .

Also useful internal pages: Los Altos Zoning, Los Altos Parking, Los Altos Design Review, Los Altos Overlay Districts, Los Altos ADUs, and the California Building Standards Code for building‑code compliance (Title 24) which is outside Title 14 land‑use rules.

Retrieved passages

• Los Altos Zoning Code (§ 3) High relevance show source text
• Los Altos Zoning Code (§ 3) High relevance show source text
• Los Altos Zoning Code (§ 100-2.1404) High relevance show source text
• Los Altos Zoning Code (section or) High relevance show source text
• Los Altos Zoning Code (§ 2) High relevance show source text
• Los Altos Zoning Code (chapter may) High relevance show source text
• Los Altos Zoning Code (Chapter 14.14.) High relevance show source text
• Los Altos Zoning Code (Chapter 14.06.) High relevance show source text

Cited sections

• Los Altos Municipal Code, Title 14 excerpts used in this page: **§ 14.06.060–110**, **§ 14.06.080**, **§ 14.06.090**, **§ 14.06.100** (R1‑10 standards) fileciteturn0file4. (Title 14)
• **§ 14.10.060–080** (R1‑20 standards) . (§ 14.10.060)
• **§ 14.08.060–080** (R1‑H standards) . (§ 14.08.060)
• **§ 14.18.050–100** (R3‑5 standards) . (§ 14.18.050)
• **§ 14.16.050–080** (R3‑4.5 district) . (§ 14.16.050)
• **§ 14.34.060–110** (OA‑1 / OA‑4.5 standards) fileciteturn0file2. (§ 14.34.060)
• **§ 14.62** (PUD standards) and **§ 14.56.070** (PC) for project/site‑specific standards fileciteturn0file11. (§ 14.62)
• **§ 14.50.170** (CT corridor design controls) . (§ 14.50.170)
• **Chapter 14.64** (ADU standards; objective standards and unit limits) — see **§ 14.64.080–100** fileciteturn0file5. (Chapter 14.64)
• Density bonus procedures and application requirements **§ 14.28.050** . (§ 14.28.050)
• Variances and exceptions: Chapter **14.81** (variance applicability and findings) — **§ 14.81.020–040** . (§ 14.81.020)
• LosAltos_ZoningCode.md

• Official Los Altos code library