Los Altos — Nonconforming Uses

Last reviewed: July 2, 2026

Overview

This page explains how Los Altos treats nonconforming uses, nonconforming structures, and nonconforming lots under the city's zoning ordinance, with the specific code sections you will need to check. The city’s general nonconforming rules live in Chapter 14.66 of the Los Altos Municipal Code; where the code cross-references other district chapters (for example downtown or ADU rules), those cross-references are noted below. See the city’s zoning menu for broader context at Los Altos Zoning & Planning overview and the detailed Los Altos Zoning pages when preparing an application. Key related topics you may need during review include Los Altos Development Standards, Los Altos Parking, Los Altos Design Review, Los Altos Overlay Districts, and Los Altos ADUs. For building-code compliance issues that are distinct from zoning, consult the California Building Standards Code.

Note: every rule below is grounded in the Los Altos Municipal Code; I summarize and interpret the rules — check the cited sections for full legal text.

What the Los Altos code requires (chapter-level summary)

• Nonconforming lots: a parcel that was legal when created but is smaller than current minimums may continue to be used subject to district rules. See § 14.66.030.
• Nonconforming structures: structures lawfully existing before current standards may continue, but may not be moved, enlarged, or altered in a way that increases the nonconformity (with limited exceptions). See § 14.66.040, § 14.66.060, § 14.66.070.
• Nonconforming uses: a lawful use that no longer conforms may continue, but may not be enlarged into new areas of the site; abandonment rules and damage/restoration rules apply. See § 14.66.090 through § 14.66.120.
• Yard/open-space and parking rules: yard space from one site cannot be credited to another; parking/ loading references are to Chapter 14.74. See § 14.66.130 and § 14.66.140–170.

Table: Key nonconforming provisions (decision-relevant)

District-by-district notes (where the code ties the district to Chapter 14.66)

Below are Los Altos districts that explicitly reference Chapter 14.66 nonconforming rules in the code or where district rules we have in the retrieved materials are directly relevant. For each district I list purpose/typical uses and the specific nonconforming tie-in or development standard the city code shows in the retrieved materials.

CD (Commercial Downtown) — CD

• Purpose/character: promote downtown design, retain village atmosphere, allow retail/restaurant/office and mixed-use. The CD district delegates nonconforming rules to Chapter 14.66. See § 14.44.020 and § 14.44.010.
• Typical permitted uses: retail, restaurants (no drive‑through), offices, mixed-use, residential-only, and uses similar in character to downtown retail (per § 14.44.030).
• Key dimensional standards: downtown-specific standards are in Chapter 14.44 (setbacks and floor‑area rules are district-specific). For nonconforming building continuations, Chapter 14.66 applies (restoration, repairs, enlargement limits). Verify with the zoning chapter for project-specific setbacks.

CRS (Commercial, Retail Services / mixed-use downtown fringe) — CRS

• Purpose/character: standards and exceptions for mixed-use residential/commercial in downtown fringe; the CRS district points to Chapter 14.66 for nonconforming use regulations. See § 14.48.140.
• Typical permitted uses: mixed retail/service and residential (see Chapter 14.48 for full list). Nonconforming continuation and restoration follow Chapter 14.66.

CN (Commercial, Neighborhood) — CN

• Purpose/character and permitted uses are listed in Chapter 14.40; nonconforming use regulations are applied via Chapter 14.66 as noted in § 14.40.180. For a CN‑zoned property that has a nonconforming use/structure, apply the Chapter 14.66 standards (repairs, abandonment, non‑enlargement).

R-1-20 (Single-family residential) — R-1-20

• Purpose/character: single-family neighborhoods (see general R-1 chapters for full purpose). Confirmed dimensional standards in retrieved materials: maximum height 2 stories / 27 ft for typical structures in R-1-20; daylight plane rules start at 11 ft at side property lines, slope inward at 25° — see § 14.10.090 and § 14.10.100. These dimensional standards interact with nonconforming structure rules (for example, restoration after damage, or when partial demolition triggers bringing the building into conformity) so Chapter 14.66 controls the continuation/restoration outcomes. § 14.10.090; § 14.10.100.
• Typical permitted uses: single‑family dwellings, accessory structures (ADU rules are in Chapter 14.14). Use Chapter 14.66 to determine whether existing nonconforming setbacks/height may continue after repair or enlargement.

Notes on districts and missing specifics: The retrieved materials explicitly link district nonconforming regulation to Chapter 14.66 for multiple commercial districts (CN, CD, CRS). Full district-by-district dimensional tables (setbacks, lot coverage, FAR) are located elsewhere in the code (district chapters and Chapter 14.06, 14.08, etc.) and should be consulted for parcel‑specific numbers — those exact per‑district tables were not fully present in the retrieved excerpts. Verify with the jurisdiction for parcel‑specific standards. Not found in retrieved materials: a complete numeric matrix of every district's setbacks, lot coverage, and FAR in one place.

Practical guidance and interpretation (plain-English synthesis)

• You may continue a nonconforming use or structural condition, but you cannot make it bigger or more nonconforming. Enlargement that increases discrepancy with current standards is prohibited (§ 14.66.100.A, § 14.66.040).
• Routine maintenance and repairs are allowed; the planning/building department controls the permissible scope (§ 14.66.060.B, § 14.66.100.B). If you plan substantial alteration, expect review for whether the change eliminates the nonconformity or must be brought to full conformity.
• If a nonconforming use stops for more than 120 days, it cannot resume without a use permit (a discretionary approval) — so temporary shutdowns over four months can force a formal permitting track (§ 14.66.110).
• If a nonconforming structure is damaged, the threshold is typically 50% (cost‑to‑restore vs replacement) for residential structures; if >50% damage or voluntary raze, rebuilding must conform to current code (§ 14.66.070, § 14.66.120). The building inspector must approve the cost estimates used for this calculation.
• ADU permitting: ministerial ADU approvals cannot be conditioned on correcting pre‑existing nonconforming zoning conditions in many cases — see § 14.14.090.G and the SB‑law–related edits reflected in § 14.64.110. That reduces the ability for a city to force a full zoning cleanup just to allow an ADU. See the ADU chapter for details and exemptions.

Checklist (what an applicant must satisfy / bring to a pre‑application)

• Determine whether the lot, structure, or use was lawful at the time it became nonconforming (show title/record map or other evidence). Check § 14.66.030 / § 14.66.050.
• If the issue is a damaged building, obtain cost estimates (restoration vs replacement) for the building inspector's review to determine the ≤50% / >50% threshold per § 14.66.070.C and § 14.66.120.C.
• If the use was discontinued, document dates of discontinuance and any occupancy within 120 days; if >120 days, prepare a use‑permit application per Chapter 14.80. See § 14.66.110.
• For proposed repairs or alterations, submit plans showing that changes will not increase the nonconformity (or show how they will eliminate it) and be ready for the building/planning department to limit maintenance scope per § 14.66.060.B.
• If the project is an ADU, reference § 14.14.090.G: the city may not require correction of preexisting nonconforming zoning conditions as a condition of ministerial ADU approval in many cases. Have ADU plans aligned with Chapter 14.14.
• Check parking obligations under Chapter 14.74 and whether Chapter 14.66 defers to those rules for existing nonconforming uses (§ 14.66.140). Link to Los Altos Parking while preparing submittals.

Risks & Ambiguities

Plain-English Summary

Los Altos lets buildings, uses, and small lots that were legal when created continue to exist, but they usually cannot be made larger or moved in ways that make them more out-of-date; if a nonconforming use stops for more than 120 days, or a structure is mostly destroyed (over 50% by cost for residences), the city generally requires rebuilding to current rules. See the specific provisions in Chapter 14.66 for the governing tests and thresholds.

Source References

• Los Altos Municipal Code, Chapter 14.66 — Nonconforming lots, structures, and uses (see § 14.66.030, § 14.66.040, § 14.66.060, § 14.66.070, § 14.66.090, § 14.66.100, § 14.66.110, § 14.66.120, § 14.66.130)
• Chapter 14.44 (CD District) purpose and permitted uses — cross-references to Chapter 14.66 for nonconforming rules (§ 14.44.010, § 14.44.020, § 14.44.030)
• Chapter 14.48 (CRS District) — nonconforming use regulations refer to Chapter 14.66 (§ 14.48.140)
• Chapter 14.40 (CN District) — nonconforming use regulations reference Chapter 14.66 (§ 14.40.180)
• R‑1‑20 district standards — height and daylight plane (example dimensional standards) (§ 14.10.090, § 14.10.100)
• ADU chapter — ministerial ADU approval and nonconforming conditions (§ 14.14.090.G) and housing development ministerial rules (§ 14.64.110)
• Parking and loading references for nonconforming uses — Chapter 14.74 referenced in § 14.66.140–170 (see nonconforming chapter)

Retrieved passages

• Los Altos Zoning Code (§ 6) High relevance show source text
• Los Altos Zoning Code (§ 2) High relevance show source text
• Los Altos Zoning Code (§ 6) High relevance show source text
• Los Altos Zoning Code (§ 6) High relevance show source text
• CBC § 66321 (§ 66321) Medium relevance show source text
• CFC § 3 (Section 14.02.070) Medium relevance show source text
• Los Altos Zoning Code (section shall) Medium relevance show source text
• CFC § 3 (§ 3) Medium relevance show source text

Cited sections

• Los Altos Municipal Code, Chapter **14.66** — Nonconforming lots, structures, and uses (see **§ 14.66.030**, **§ 14.66.040**, **§ 14.66.060**, **§ 14.66.070**, **§ 14.66.090**, **§ 14.66.100**, **§ 14.66.110**, **§ 14.66.120**, **§ 14.66.130**) (§ 14.66.030)
• Chapter **14.44** (CD District) purpose and permitted uses — cross-references to Chapter **14.66** for nonconforming rules (**§ 14.44.010**, **§ 14.44.020**, **§ 14.44.030**) (§ 14.44.010)
• Chapter **14.48** (CRS District) — nonconforming use regulations refer to Chapter **14.66** (**§ 14.48.140**) (§ 14.48.140)
• Chapter **14.40** (CN District) — nonconforming use regulations reference Chapter **14.66** (**§ 14.40.180**) (§ 14.40.180)
• R‑1‑20 district standards — height and daylight plane (example dimensional standards) (**§ 14.10.090**, **§ 14.10.100**) (§ 14.10.090)
• ADU chapter — ministerial ADU approval and nonconforming conditions (**§ 14.14.090.G**) and housing development ministerial rules (**§ 14.64.110**) (§ 14.14.090.G)
• Parking and loading references for nonconforming uses — Chapter **14.74** referenced in **§ 14.66.140–170** (see nonconforming chapter) (§ 14.66.140)
• LosAltos_ZoningCode.md

• Official Los Altos code library