Local zoning · Colma

Colma — Nonconforming Uses

Q: What happens if my nonconforming building is 60% damaged by fire — can I rebuild?

If damage exceeds 50% of the building’s value, you may not reconstruct unless every portion is made to conform to current zoning requirements ; repairs under the 50% threshold are allowed up to that limit. See § 5.03.310(b) for the statutory threshold and requirement.

Q: Can I expand a nonconforming commercial use in Colma?

No — a nonconforming use may be continued but may not be expanded or extended on the same or adjoining property; any change must be to a use of the same or a more restricted classification ( § 5.03.310(d)–(e) ).

Q: Do ADU rules force me to correct unrelated zoning nonconformities on my lot?

Generally no. § 5.03.108 says the Town will not deny an ADU or JADU simply because of a nonconforming zoning condition or building‑code violation that is not a threat to health/safety and is not affected by the ADU construction. If the nonconformance does affect the ADU or threatens safety, the Town may require correction.

Q: Where in the code do I find the R‑zone setback and height rules that matter for a nonconforming structure?

Residential development standards including front yard 15 ft , side and rear setback rules, and maximum heights are in § 5.03.082 and the tables that follow (development standards). Use those when assessing whether alterations would “conform” or not.

Nonconforming Uses under the Colma local zoning and planning code, with the controlling citations.

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Last reviewed: July 1, 2026

Overview

Colma’s rules on nonconforming uses, nonconforming structures, and nonconforming lots are collected in the Zoning Code provisions for Non‑Conforming Buildings and Uses and related ADU provisions. The local framework allows existing nonconforming uses to continue in a limited way, restricts expansion, sets a 50% damage/reconstruction threshold, and includes ADU-specific limits on denial where a nonconforming condition exists. Key controlling provisions include § 5.03.310 (Non‑Conforming Building and Uses) and § 5.03.108 (ADU conditions) of the Colma Zoning Code.

How Colma treats nonconforming conditions (plain rules you’ll rely on)

A non‑conforming building may be maintained and repaired, but structural alterations, enlargements or moving the building on the lot are restricted unless the entire building is made to conform to the current zone rules; see § 5.03.310(a).
If a non‑conforming building is damaged more than 50% of its value, restoration is limited: repairs are allowed only up to 50% of value; if damage exceeds 50% no reconstruction is allowed unless the whole building meets current zone regulations (§ 5.03.310(b)).
A non‑conforming use that lawfully existed when the ordinance became effective may continue, but may not be expanded; changes must be to the same or a more restricted classification, and vacancy rules apply (one‑year re‑occupancy windows) (§ 5.03.310(c)–(d)).
Non‑conforming land uses (no building) may continue but may not be expanded; if discontinued any future use must conform (§ 5.03.310(e)).
ADU applications may not be denied solely because of an unrelated nonconforming zoning condition, building code violation, or unpermitted structure on the lot unless it creates a public health/safety threat or is affected by the ADU construction — see § 5.03.108 (ADU conditions).

District-by-district breakdown (what the district is, typical uses, dimensional standards, where it applies)

Notes: For each district below I summarize the district purpose and typical permitted uses from the Colma Zoning Code; dimensional highlights reference the townwide development standards where applicable. For full development‑standard tables and nuance, see § 5.03.220 and the zone subsections cited for each district.

G — Golf and Cemetery Zone

Purpose: preserve and regulate cemetery, memorial park, golf and related open uses; additional design and development standards layered with the townwide standards (§ 5.03.070).
Typical permitted uses: cemetery/memorial park, agriculture/open field, golf course, driving range; accessory cemetery uses may be council‑permitted (flower shops, crematoriums, monument shops) (§ 5.03.071).
Key standards: Development in G must also comply with the DR overlay where applicable and the applicable Design Review standards (§ 5.03.072).
Where it applies: properties zoned G; special limits on visibility, small accessory structures exempted administratively in some cases (§ 5.03.071(c)).

R — Residential Zone

Purpose: single‑ and low‑density residential, preserve neighborhood character (§ 5.03.080).
Typical permitted uses: single‑family dwelling, manufactured homes, small family day care, multi‑unit up to six units, Accessory Dwelling Units (ADUs) (see ADU chapter), group homes, transitional and supportive housing (§ 5.03.081).
Key dimensional standards: front yard 15 ft, side setbacks = 10% of lot width or 10 ft (whichever is less), rear similar percent/limits, max height 27 ft (single‑family measure shown in Table); see § 5.03.082 and the development standards table.
Where it applies: all properties mapped R; accessory buildings under 120 sq ft have special allowance /§ 5.03.082(c)(1).

R‑S — Sterling Park Neighborhood Residential Zone

Purpose: tailored residential rules for the Sterling Park neighborhood (§ 5.03.090).
Typical permitted uses: single‑family, manufactured home, group homes, community parks/public buildings, SRO, supportive/transitional housing, ADUs within existing single‑family (§ 5.03.091).
Key standards: development standards are the R‑zone baseline unless otherwise noted in § 5.03.090–091.

C — Commercial Zone

Purpose: neighborhood and regional commercial uses; mixed commercial and residential above ground‑floor is contemplated (§ 5.03.130).
Typical permitted uses: offices, retail, restaurants, multi‑family up to six units, emergency shelter/low‑barrier navigation center (where permitted), and administrative/conditional uses listed in § 5.03.132.
Key standards: commercial development standards including front setbacks 5 ft (20 ft for commercial center), maximum heights (40 ft typical), lot coverage limits — see § 5.03.133 and the Non‑Residential Standards table.
Where it applies: mapped C parcels; residential uses in C follow the R zone residential rules when applied (§ 5.03.133(a)(1)).

P — Public Zone

Purpose & scope: public uses; code states “no restrictions” other than consistency with other Town uses (§ 5.03.163).

E — Executive / Administrative Zone

Purpose: cemetery, floriculture, and office‑type uses; includes medical and professional offices with some conditional uses (§ 5.03.170–171).
Key standards: minimum lot widths/depths, setbacks and heights listed in § 5.03.172.

PD — Planned Development

Purpose: flexible, project‑level rules set via Conceptual and Detailed Development Plans (§ 5.03.184–186).
Typical permitting: uses require a Use Permit in PD and must meet concept plan findings; dimensional standards are set in the PD approval (see § 5.03.185–186).

Overlays / Combining Zones

DR (Design Review) overlay: the DR overlay applies to many properties fronting on El Camino Real, Mission Road etc.; design standards and procedures are in § 5.03.150–153, and they apply in addition to base zone rules (design review can affect nonconforming alterations where historical character is involved).

Decision‑critical table: common nonconforming questions at a glance

Rule / Topic	Quick rule (Colma)	Code Reference
Continue an existing nonconforming use	May continue but may not be expanded; must change only to same/more‑restricted classification; vacancy rules apply	§ 5.03.310(c)–(e)
Structural alterations	No structural alteration or enlargement of a building non‑conforming as to use, unless whole building made to conform	§ 5.03.310(a)
Damage/rebuild threshold	Repairs allowed if damage ≤ 50% of value; if >50% must make building conform to current zone for reconstruction	§ 5.03.310(b)
Non‑conforming land use (no building)	May continue but cannot be expanded; if discontinued future use must conform	§ 5.03.310(e)
ADU permit and nonconformance	Town will not deny ADU/JADU solely because of nonconforming zoning conditions that do not create health/safety threats or are not affected by ADU construction	§ 5.03.108
R‑Zone front setback	Front yard 15 ft (R zone development standard)	§ 5.03.082 and Table
G‑Zone permitted uses	Cemetery, agriculture/open field, golf course, driving range; council may permit accessory cemetery uses	§ 5.03.071

Checklist — what an applicant must satisfy (if you have a nonconforming condition)

Confirm whether the use or structure is legally non‑conforming under § 5.03.310 (history and continuity); collect evidence of legal prior use.
If proposing repairs after damage, document repair cost vs. building value to apply the 50% rule in § 5.03.310(b).
If proposing a change of use, ensure the new use is the same or more restricted classification — otherwise conforming use is required (§ 5.03.310(c)–(d)).
If adding an ADU, confirm whether the lot has a nonconforming zoning condition; know that per § 5.03.108 Colma may not deny the ADU solely for an unrelated nonconformance unless it’s a health/safety problem. See also ADU size and zone allowances.
Check whether the property lies in a Combining/Overlay zone (for example the DR overlay) — design review rules may apply to alterations (§ 5.03.150–153).
For any proposed expansion/relocation, confirm that the action does not violate the prohibition on expansion of nonconforming uses or moving a nonconforming building without full conformance (§ 5.03.310(a),(d)).
Verify required parking, development standards and possible design review filings early.

Risks & Ambiguities

Issue	Why it matters	What to verify
How “value” is calculated for the 50% damage rule	The 50% rebuild threshold in § 5.03.310(b) controls whether you must fully conform on reconstruction; different valuation methods (market value vs. replacement cost) can change the outcome	Verify with the Town how “value” is measured (appraisal method accepted by Planning/Building), and get a written determination before major work.
Vacancy/time windows for re‑occupancy	§ 5.03.310(c) contains the one‑year re‑occupancy rule — failing that can force conformity	Confirm the effective date that starts the one‑year clock; get documented proof of use within one year or seek an administrative determination.
Whether a proposed ADU is “affected by” a nonconforming condition	§ 5.03.108 prevents denial for nonconformance unless the nonconformance is affected by ADU construction or threatens safety — interpreting “affected” is fact‑specific	Provide plans showing the ADU footprint and separation from nonconforming elements; request a written finding on whether the nonconformance affects the ADU.
Applicability of Design Review overlay to a repair or alteration	DR overlay standards (§ 5.03.150–153) can add requirements that affect scope and aesthetics of repairs	Confirm whether the parcel falls in the DR area and whether the proposed work is an exception (historical compatibility exceptions exist).
Whether an existing use is “legal nonconforming”	Code distinguishes legal nonconforming uses and uses that were unlawful or abandoned — consequences differ	Provide permit history, tax records, photographs, and business licenses to the Planner for a legal nonconforming determination.

Plain‑English Summary

If your property or business in Colma doesn’t meet a current zoning rule, you can usually keep operating the same way, but you generally cannot expand or move the nonconforming part; if the building is more than 50% destroyed you’ll need to rebuild to current rules. For ADUs, Colma cannot deny a permit just because there’s an unrelated nonconformity on the lot unless it threatens health/safety or the ADU would be directly affected. Always verify value and vacancy dates with the Town before rebuilding or changing use. § 5.03.310 and § 5.03.108 are the controlling rules.

Source References

Colma Zoning Code — Non‑Conforming Buildings and Uses, § 5.03.310 (purpose and rules on maintenance, repairs, 50% rule, change of use, land nonconforming):
Colma Zoning Code — ADU Conditions for Nonconforming Uses and Structures, § 5.03.108 (ADU permit limitations related to nonconforming zoning conditions):
Colma Zoning Code — Zone summary and land use table (G, R, R‑S, C, P, E, PD columns and permitted use symbols):
G Zone (Golf & Cemetery) permissions and development standards: § 5.03.070–072.
R Zone (Residential) permitted uses and development standards: § 5.03.080–082.
R‑S Sterling Park neighborhood rules: § 5.03.090–091.
C Zone (Commercial) permitted uses and standards: § 5.03.130–133.
P Zone development statement: § 5.03.163.
E Zone (Executive) purpose and standards: § 5.03.170–172.
DR Design Review overlay and procedures: § 5.03.150–153.
ADU state standard cross‑references and local ADU chapter summarizing zones allowed and ministerial rules: Colma ADU chapter (see table/summary in § 5.03.100 et seq.) and State ADU references in local code.

Sources

Retrieved passages

Colma Zoning Code (§ 5.344) High relevance
CBC § 5.344 (§ 5.344) High relevance
Colma Zoning Code (section with) High relevance
Colma Zoning Code (section of) High relevance
CBC § 66322 (section 66322) High relevance
CPC § 5.03.105 (section 5.03.105) Medium relevance
CBC § 5.311 (§ 5.311) Medium relevance
Colma Zoning Code (section 5.03.251) Medium relevance
CBC § 66314 (§ 66314) Medium relevance
Colma Zoning Code Medium relevance
CBC § 202 (section 202) Medium relevance
Colma Zoning Code (§ 5.331) Medium relevance
Colma Zoning Code (§ 5.330) Medium relevance
Colma Zoning Code (Section 5.03.232) Medium relevance
Colma Zoning Code (§ 5.330) Medium relevance

Cited sections

Official Colma code library

Frequently asked questions

What happens if my nonconforming building is 60% damaged by fire — can I rebuild?

If damage exceeds 50% of the building’s value, you may not reconstruct unless every portion is made to conform to current zoning requirements; repairs under the 50% threshold are allowed up to that limit. See § 5.03.310(b) for the statutory threshold and requirement.

Can I expand a nonconforming commercial use in Colma?

No — a nonconforming use may be continued but may not be expanded or extended on the same or adjoining property; any change must be to a use of the same or a more restricted classification (§ 5.03.310(d)–(e)).

Do ADU rules force me to correct unrelated zoning nonconformities on my lot?

Generally no. § 5.03.108 says the Town will not deny an ADU or JADU simply because of a nonconforming zoning condition or building‑code violation that is not a threat to health/safety and is not affected by the ADU construction. If the nonconformance does affect the ADU or threatens safety, the Town may require correction.

If I stop using land that was a legal nonconforming use, can I resume it later?

Colma treats a discontinued nonconforming land use strictly: if the nonconforming use or portion thereof is discontinued, any future use must conform to the ordinance (§ 5.03.310(e)). Document continuity carefully.

Does the Design Review (DR) overlay affect repairs to a nonconforming building?

Possibly. The DR overlay standards apply in the mapped area and may govern alterations; but there are exceptions where applying DR standards would clash with an established historic or architectural theme. Check § 5.03.150–153 and confirm if your parcel is in the DR area.

Where in the code do I find the R‑zone setback and height rules that matter for a nonconforming structure?

Residential development standards including front yard 15 ft, side and rear setback rules, and maximum heights are in § 5.03.082 and the tables that follow (development standards). Use those when assessing whether alterations would “conform” or not.

Is a warehouse in the R‑zone automatically a nonconforming use?

If a use exists that is not permitted by the current zone, it may be nonconforming; the Land Use table shows permitted uses by zone and indicates where uses are nonconforming or require permits. Confirm the parcel’s zoning and use history and consult § 5.03.050 et seq. for the land‑use table.

Can I move a nonconforming building to another location on my lot?

No — the code prohibits moving a nonconforming building in whole or part on the lot unless every portion of the building is made to conform to the zone’s requirements (§ 5.03.310(a)).

If my nonconforming business predates the current code, can the Town force immediate closure?

Not automatically. Colma allows continuation of legal nonconforming uses, but if a nonconforming use is causing nuisances, safety issues, or violates other statutes, enforcement or abatement actions may follow. The nonconforming use rules (and other enforcement provisions) apply — start with § 5.03.310.

Where are Colma’s commercial development standards that may force a nonconforming business to conform on rebuild?

Non‑residential development standards (front/rear/side setbacks, heights, lot coverage) are in the Non‑Residential Standards table and in § 5.03.133 for the C Zone and § 5.03.072 for G Zone overlays; compare to § 5.03.310(b) (50% rule) to see when full conformance is required.

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