Local zoning · Fairfax

Fairfax — Nonconforming Uses

Q: If my nonconforming house is damaged in a fire, can I rebuild it the same way?

If destruction is 50% or less of the building (as defined in § 17.016.040(B)), you may restore and resume the nonconforming use if restoration starts within one year and proceeds diligently; if destruction exceeds 50% , the rebuilt structure may not increase nonconformity and discrepancies require Planning Commission approval. See § 17.016.070 .

Q: Does parking affect whether I can do alteration work on a nonconforming building?

Yes. One exception to the 50% limit requires that off-street parking requirements are met or a variance for parking is granted; check Chapter 17.052 (off‑street parking) and the exception in § 17.016.040(C) .

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

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Last reviewed: July 2, 2026

Overview

This page summarizes what the Town of Fairfax zoning ordinance (Title 17) says about nonconforming uses, nonconforming structures, and nonconforming lots — what may continue, what may be changed, and when a nonconformity must end. Read this as a plain-English companion to the local code; every rule cited below is grounded in the Town Zoning Code. For background on how these rules interact with district rules, see the Town's general Fairfax Zoning and Fairfax Development Standards pages.

IMPORTANT LINKS (first natural mentions): the town's rules about parking interact with nonconforming alterations, see Fairfax Parking; design-review constraints may apply, see Fairfax Design Review; accessory dwelling units and nonconforming zoning conditions are discussed in the ADU chapter, see Fairfax ADUs; overlay rules can override zone rules, see Fairfax Overlay Districts; if you need an exception, see Fairfax Variances and Exceptions; Town signage and frontage rules can affect commercial nonconformities, see Fairfax Signage. Where building-code details matter, confirm with the California Building Standards Code.

All code citations below are to Title 17 of the Fairfax Municipal Code (Zoning). See the Source References section for the exact § citations and file-source markers.

Core rules (what the code actually says)

Definitions / policy: a "legal non-conforming use" is a use or structure lawfully established prior to an ordinance change but not conforming under current Title 17. The chapter aims to allow continued use while limiting enlargement and eventual elimination of nonconformities. See § 17.016.010 .
Continuation and routine maintenance: an existing nonconforming use or structure may be continued and may receive routine maintenance and repairs. See § 17.016.020 .
Alterations and additions (uses): no nonconforming use may be moved, altered, or enlarged in a way that increases the nonconformity unless required by law or unless the change eliminates the nonconforming use. See § 17.016.030 .
Alterations and additions (structures): a nonconforming structure may not be moved, altered, enlarged, or reconstructed so as to increase the discrepancy with current coverage, floor area, yard, height or spacing standards without a variance under Chapter 17.028. In addition, cumulative work after October 2, 2009 is limited so it does not affect more than 50% of floor area or expand floor area by more than 50%, nor allow the addition of a bedroom that would otherwise be prohibited. See § 17.016.040(A) and (B) .
Exceptions to the 50% rule: certain limited work (e.g., window/door replacement, insulation, interior cosmetic work, roof repairs that do not change roof configuration, earthquake preparedness, alternative energy installations) is not counted toward the 50% cap. Also, the cap does not apply when (a) off-street parking requirements are met or a variance granted, (b) the work does not increase or create a new nonconformity, and (c) the building is not in Ridgeline Development or Flood Zones. See § 17.016.040(C) .
Change of nonconforming use: a nonconforming use cannot be changed to another nonconforming use except by use permit and terms set by the Town Council. See § 17.016.050 .
Abandonment: if a nonconforming use that originally required the structure's design ceases for 12 months or more, it cannot be re-established as a nonconforming use. If the structure was not originally designed for the nonconforming use, a cessation of 6 months or more prevents re-establishment. See § 17.016.060 .
Restoration after damage: if a nonconforming structure is destroyed to 50% or less (as measured under § 17.016.040(B)), it may be restored and the nonconforming use resumed if restoration begins within one year (or the period required by law) and proceeds diligently. If destruction exceeds 50%, restoration may not increase prior nonconformity and must conform to Title 17 to the greatest extent possible; discrepancies require Planning Commission approval. See § 17.016.070 .
Filling (service) stations: special rules allow continued operation of lawful service stations existing before 2023 but tightly limit enlargement related to fossil-fuel storage and dispensing; environmental or EV-charging upgrades are allowed with conditions. See § 17.016.080 .
Interaction with ADUs: the ADU chapter expressly states the Town will not deny an ADU application because of a nonconforming zoning condition that does not create a threat to public health and safety or is not affected by ADU construction. Nonconforming ADUs may still be legalized subject to state law and local ADU rules. See Chapter 17.048 (ADUs) and the ADU-specific nonconformance language § (ADU chapter, divisions I and J) .

District-by-district notes (how nonconformities interact with specific Fairfax zones)

Below are Fairfax zone chapters where nonconforming rules commonly arise. For each district I list the chapter number, what the chapter is for (purpose), common permitted types, key dimensional rules that typically govern whether a structure is nonconforming, and where the chapter applies. If the uploaded materials did not include the full text for a zone, I indicate that and point to the general rules that apply.

RS-7.5 (Chapter 17.076) — Single-Family Residential, medium density

Purpose / typical uses: single-family homes, customary accessory uses. The chapter designation is 17.076 in Title 17. See Title listing § 17.076 .
Key dimensional standards that determine nonconformity: residential lot coverage limit and setbacks (see general standards § 17.040.020 and residential coverage § 17.22.010). If a house predates an amendment, it may be nonconforming for yard, height, coverage or floor area limits. See § 17.040.020 and § 17.22.010 .
Where it applies: properties shown as RS-7.5 on the official Zoning Map; check § 17.012 for boundaries. See § 17.012 (zones list) .
Code text for RS-7.5 specifics: Not found in retrieved materials (retrieve Chapter 17.076 for parcel-specific standards). Verify with the Planning Department.

RS-6 (Chapter 17.080) — Single-Family Residential, higher density

Purpose / typical uses: single-family homes; see Title listing § 17.080 for chapter reference. See § 17.080 listing .
Dimensional controls that cause nonconformity: same town-wide coverage, setback and height standards apply (see § 17.040.020 and § 17.22.010). See § 17.040.020 and § 17.22.010 .
Chapter details: Not found in retrieved materials. Verify with local code chapter 17.080.

RD 5.5-7 (Chapter 17.084) — Residential density band

Purpose / typical uses: multiple-family or attached units per RD standards; see Title listing § 17.084 .
Dimensional controls: same general limits for coverage and setbacks; floor area caps and special existing-structure rules can apply (see § 17.136.030/040 for floor area limits and existing-structure provisions). See § 17.136.030(B) and § 17.136.040 .
Chapter text not retrieved in full: Not found in retrieved materials. Verify with Chapter 17.084.

RM (Chapter 17.088) — Multiple-Family Residential

Purpose / typical uses: multi-family dwellings, apartments. See Title listing § 17.088 .
Dimensional controls: density, setbacks, parking (Chapter 17.052), and multi-family design standards (Chapter 17.138) influence whether a building is nonconforming. See § 17.100.070 and § 17.052 references .
Chapter text not fully retrieved here. Verify with Chapter 17.088.

CC — Central Commercial (Chapter 17.100) — bold: CC

Purpose / typical uses: retail, pedestrian-oriented storefronts, local services. See § 17.100.040 (permitted uses) and § 17.100.060 (accessory uses) .
Key dimensional standards: height limits for principal buildings: 28.5 ft on gentle slopes, up to 35 ft on downslope lots; density minimums and accessory restrictions are in § 17.100.070–080 and general standards. See §§ 17.100.070–080 .
Where it applies: parcels shown CC on the official Zoning Map. Nonconforming commercial structures are subject to the same nonconforming chapter limits (Chapter 17.016) and to sign rules in Chapter 17.064; check both when changing storefronts. See §§ 17.016.010 and 17.064 .

CH — Highway Commercial (Chapter 17.096)

Purpose / typical uses: highway- and auto-oriented commercial uses (e.g., service, retail). See Title listing § 17.096 .
Interaction with nonconformity: special rules apply to fuel/service stations under § 17.016.080; enlargement of fuel-storage features is tightly restricted. See § 17.016.080 .

CR — Commercial Recreation (Chapter 17.108)

Purpose / typical uses: parks, commercial recreation; accessory uses are tightly controlled and coverage limits are low (10% coverage in some cases). See § 17.108.040 and § 17.108.050 .
Where it applies: parcels designated CR on the map. Nonconforming recreational structures are limited in enlargement and are subject to Chapter 17.016 rules. See § 17.016.040 .

PD — Public Domain (Chapter 17.130) — bold: PD

Purpose / typical uses: public facilities and uses serving community needs. See § 17.130.020–040 for permitted and accessory uses and the director-use-determination process .
Dimensional standards: height cap of 28.5 ft (general) and no site-yard requirements except when adjacent to residential zones; check § 17.130.070–080. See §§ 17.130.070–080 .
Nonconforming PD uses: subject to Chapter 17.016 limitations and to any special public-purpose approvals. See § 17.016.010 .

SF-RMP — Single-Family Residential Master Planned District (Chapter 17.116)

Purpose / typical uses: master-planned, site-specific single-family development with additional site-prep and environmental rules. See § 17.116.070 for site-preparation and applicability; design rules and off-street parking requirements referenced here may affect nonconforming repair or rebuilding. See § 17.116.070 and § 17.052 .

Notes on district coverage: In many places the code defers to the official Zoning Map for exact boundaries; where a chapter's text was not found in the retrieved materials, the chapter is still listed in the Title 17 table of contents and general nonconforming rules (Chapter 17.016) apply across zones. See Title 17 table of contents § 17.004–17.132 for chapter listings .

Quick-reference table — most decision‑relevant nonconforming standards

Rule / test	What it means in practice	Controlling code cite
Definition / policy	Uses/structures lawfully existing before a zoning change may continue but are to be limited and phased out	§ 17.016.010
Continue / maintain	Routine repairs allowed; use may continue until abandonment or other limits apply	§ 17.016.020
No enlargement of nonconforming use	You may not enlarge a nonconforming use into additional space or another parcel without permit	§ 17.016.030
No increase in structural nonconformity	Cannot alter a nonconforming structure so it becomes more nonconforming without a variance	§ 17.016.040(A)
50% cumulative work cap	After 10/2/2009, cumulative work cannot affect > 50% of floor area or expand floor area > 50% (with stated exceptions)	§ 17.016.040(B)–(C)
Abandonment	Re-establishment barred after 6 months or 12 months depending on whether building was originally designed for the use	§ 17.016.060
Destruction/restoration	Damage ≤ 50% may be rebuilt if started within 1 year; > 50% rebuilt only to reduce nonconformity and with Commission review for discrepancies	§ 17.016.070
Service stations	Historic stations may continue but fuel-storage/enlargement restricted; environmental/EV upgrades allowed	§ 17.016.080
ADUs on nonconforming lots	ADU permit may not be denied solely because of a nonconforming zoning condition that is not a health/safety threat or affected by the ADU	Chapter 17.048 (ADUs) divisions I & J

Checklist — what an applicant must satisfy to alter or restore a nonconforming use/structure

Demonstrate that the use or structure was lawfully established on the effective date (provide floor plans of record or other evidence) § 17.016.070
Confirm the proposed work will not increase an existing nonconformity (or obtain a variance under Chapter 17.028) § 17.016.040(A)
Calculate cumulative affected floor area to verify the 50% threshold has not been or will not be exceeded (§ 17.016.040(B)); exclude exempted work as described in § 17.016.040(C)
Show off-street parking complies or obtain a variance where parking is part of exception § 17.016.040(C) and check Fairfax Parking
If a change of use is proposed, determine whether the new use is conforming; changing one nonconforming use to another requires a Town Council use permit § 17.016.050
If restoration after damage > 50%, prepare plans that bring the structure into greatest conformity possible and prepare to present discrepancies to the Planning Commission § 17.016.070
If in an overlay (WHO, Ridgeline, Flood), confirm overlay-specific constraints; see Fairfax Overlay Districts and the overlay chapters in Title 17 (e.g., Ridgeline § 17.060, Flood § 17.068)

Risks & Ambiguities

Issue	Why it matters	What to verify
Damage percentage (≤50% vs >50%)	Rebuilding rights differ sharply — ≤ 50% allows resumption; > 50% restricts restoration and may force conformity upgrades § 17.016.070	Verify how “affected floor area” is calculated under § 17.016.040(B) and produce floor plans of record § 17.016.070
Abandonment clock (6 vs 12 months)	Whether a use can be re-established depends on whether the building was originally designed for the nonconforming use § 17.016.060	Confirm original design intent via permits, building plans or evidence on file with Planning & Building Services § 17.016.070
Cumulative 50% cap after 2009	Projects that appear minor could inadvertently count toward the cap and block larger future work § 17.016.040(B)	Prepare cumulative work accounting since 10/2/2009; ask staff for pre-2009 baseline if needed § 17.016.040(B)
Nonconforming ADUs and legalization	State ADU law limits local denial based on nonconforming conditions, but local ADU objective standards still apply (and safety violations can be enforced) ADU chapter (17.048) divisions I–J	Confirm whether the ADU is affected by the nonconforming condition; get ADU completeness review from the Town § 17.048
Service station constraints	Fuel-storage is specially regulated; enlarging fossil-fuel capacity is prohibited while environmental upgrades and EV charging are allowed with conditions § 17.016.080	For stations, obtain Director/Commission guidance and check environmental / stormwater permit requirements § 17.016.080
Overlay conflicts (Ridgeline, Flood)	Some exceptions to nonconforming rules are disallowed inside overlays (e.g., no exceptions under § 17.016.040(C)(2)(c)) § 17.016.040(C)	Verify overlay status for parcel and consult the overlay chapter (e.g., Ridgeline § 17.060)

Plain-English Summary

If your Fairfax building or business was legal under an older zoning rule but now violates the current rules, you can usually keep it and do routine repairs; you generally cannot enlarge the nonconformity, and big rebuilds or changes are limited by specific time and percentage tests (notably a 50% cumulative work threshold and 6–12 month abandonment rules). Always check the relevant zone chapter and bring documentation to the Planning Department — many of the key limits and exceptions are in Chapter 17.016 (Non‑Conforming Uses and Structures) of Title 17. See §§ 17.016.010–070 .

Source References

Fairfax Zoning Code, Chapter 17.016 (Non‑Conforming Uses and Structures): § 17.016.010 – § 17.016.080 .
CC zone — Central Commercial: § 17.100.060 – § 17.100.080 (accessory uses, building site requirements, height) .
PD zone — Public Domain: § 17.130.040 – § 17.130.080 (uses, height, yards) .
SF‑RMP site‑prep and related rules: § 17.116.070 .
General setbacks and coverage: § 17.040.020 (setbacks) and residential coverage limit § 17.22.010 (35% residential coverage cap) .
Floor area caps and existing structure rules: § 17.136.030(B) and § 17.136.040 (floor area and existing structures) .
ADU chapter and nonconformance language: Chapter 17.048 and divisions addressing nonconforming zoning conditions and legalization of ADUs and JADUs .
Title 17 table of contents and zone chapter listings (to find chapter numbers): Title listing § 17.004–17.132 .

(If you need direct links to any specific chapter text or a parcel‑specific determination, verify with the Fairfax Planning & Building Services department; where a zone chapter detail was not present in the retrieved materials I have noted "Not found in retrieved materials".)

Sources

Retrieved passages

Fairfax Zoning Code (Chapter 17.060) High relevance
Fairfax Zoning Code (chapter is) High relevance
Fairfax Zoning Code (Title 17) High relevance
Fairfax Zoning Code (§ 17.10.020) High relevance
Fairfax Zoning Code (§ 17.012.180) High relevance
CPC § 17920.3 (§ 17920.3.) Medium relevance
Fairfax Zoning Code (§ 17.100.040) Medium relevance
Fairfax Zoning Code (§ 17.130.030) Medium relevance
Fairfax Zoning Code (§ 17.016.070) High relevance

Cited sections

Official Fairfax code library

Frequently asked questions

What is a legal nonconforming use in Fairfax?

A legal nonconforming use is a use or structure lawfully established before a change in Title 17 that now violates current use or development rules; the Town allows continuation but restricts enlargement and reestablishment after abandonment. See § 17.016.010 .

How long can a nonconforming use be unused before it can’t be reestablished?

If the building was originally designed for the nonconforming use, cessation of 12 months bars re‑establishment; if the building was not originally designed for it, 6 months applies. See § 17.016.060 .

If my nonconforming house is damaged in a fire, can I rebuild it the same way?

If destruction is 50% or less of the building (as defined in § 17.016.040(B)), you may restore and resume the nonconforming use if restoration starts within one year and proceeds diligently; if destruction exceeds 50%, the rebuilt structure may not increase nonconformity and discrepancies require Planning Commission approval. See § 17.016.070 .

Can I add a room or bedroom to a nonconforming house?

After October 2, 2009, cumulative construction on a nonconforming structure cannot affect more than 50% of floor area or expand it by more than 50%, and it cannot result in addition of a bedroom in such residential buildings unless the specific exceptions apply. See § 17.016.040(B) .

If my lot is nonconforming on setbacks or coverage, can I still build an ADU?

The ADU chapter says the Town will not deny an ADU permit solely because of a nonconforming zoning condition that does not present a threat to public health and safety and is not affected by the ADU construction; ADUs remain subject to the ADU chapter’s objective standards. See Chapter 17.048 divisions I–J .

Can a nonconforming commercial use switch to a different nonconforming commercial use?

No — changing from one nonconforming use to another nonconforming use is prohibited unless a use permit is issued by the Town Council under specified terms. See § 17.016.050 .

What happens if my property sits inside a Ridgeline or Flood overlay?

Overlay chapters can limit exceptions that might otherwise apply to nonconforming repairs or alterations; certain nonconforming exceptions expressly do not apply inside Ridgeline or Flood Zones. See § 17.016.040(C) and the Ridgeline/Flood chapters (e.g., § 17.060 and § 17.068) .

Do I need a variance to change a nonconforming structure?

If the proposed change would increase the discrepancy between the structure and Title 17 standards (coverage, FAR, yards, height), a variance under Chapter 17.028 is required. See § 17.016.040(A) and Chapter 17.028 references .

Does parking affect whether I can do alteration work on a nonconforming building?

Yes. One exception to the 50% limit requires that off-street parking requirements are met or a variance for parking is granted; check Chapter 17.052 (off‑street parking) and the exception in § 17.016.040(C) .

If I disagree with a Planning Director determination about a nonconforming use, what can I do?

Many discretionary matters (e.g., use permits, variance decisions) are heard by the Planning Commission and are appealable per Title 17 procedures; consult Chapters 17.032 (use permits) and 17.036 (appeals) for process and timelines. See §§ 17.032.060 and related procedural sections .

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