Fairfax Zoning, Planning & Building Codes

Last reviewed: July 25, 2026 · AI-generated overview · General information, not legal advice · detailsless

Compiled with AI research tools from official sources. Verify with the jurisdiction.

Overview

Fairfax regulates land use through Title 17 of the municipal code, which establishes zones, overlay districts, objective standards, and a discretionary review framework tailored to the town’s steep hillsides and creek corridors. The official zoning map controls where each district applies and is kept by the Town Clerk (§ 17.012.020). Most commercial and multi-family projects, and many single‑family expansions, pass through planning/design review before building permits are issued (§ 17.020.120). Fairfax also layers in hillside standards through the HRD overlay, slope‑sensitive lot-sizing, and state-aligned housing tools like ADUs and density bonus.

The baseline rule is simple: use land and build only as the zoning allows, and don’t exceed district limits on height, setbacks, and site area; Fairfax will not issue permits or licenses if required design review has not been approved (§ 17.004.140; § 17.020.120).

How Fairfax’s code is organized

Use this roadmap to find the right rule quickly:

• Districts and the map
  • Zone districts are established and mapped in Chapter 17.012; the official zoning map is on file with the Town Clerk (§ 17.012.020; § 17.012.040). Boundary listings identify specific districts, including RS‑6 (§ 17.012.060), RD 5.5–7 (§ 17.012.070), RM (§ 17.012.080), commercial districts CL/CH/CC/CS (§§ 17.012.090–.120), CR (§ 17.012.130), PDD/PD (§§ 17.012.140, 17.012.170), O‑A (§ 17.012.150), UR (§ 17.012.160), WHO‑A/WHO‑B (§ 17.012.165), and RM‑S (§ 17.012.180). See Fairfax Zoning.
• Citywide/general standards
  • General zone regulations centralize town‑wide rules for lot coverage, setbacks (including sidewalks and creek‑adjacent areas), signage references, fire protection and permit timing in Chapter 17.040 (see § 17.040.010; § 17.040.020; § 17.040.030; § 17.040.040; § 17.040.110). Explore Fairfax Development Standards.
• District chapters with standards
  • Single-family: RS‑6 standards include slope‑responsive lot‑size, height, and yard regulations (§ 17.080.050; § 17.080.060).
  • Multi-family: RM standards include uses, yards, height, parking, and driveway standards (Chapter 17.088; e.g., § 17.088.030; § 17.088.060; § 17.088.070).
  • Senior multi-family: RM‑S parallels RM with senior‑specific provisions and height/yards (Chapter 17.090; e.g., § 17.090.070; § 17.090.080).
  • Commercial recreation: CR requires design review and ties to parking and signage rules (§ 17.108.020; § 17.108.060).
• Overlays/combining districts
  • HRD overlay adds objective hillside development standards and a clustered option (§ 17.072.090).
  • A Agricultural & Conservation District is a combining district that can overlay RS‑7.5/RS‑6/PD and controls if in conflict (§ 17.120.010).
  • WHO‑A/WHO‑B overlays are mapped in § 17.012.165 (standards not provided in source materials).
• Permits and review
  • Design review submittal and hearing procedures (§ 17.020.050; § 17.020.080).
  • Parking—base ratios live in Chapter 17.052; mixed‑use and affordable‑housing parking modifications live in § 17.126.070. See Fairfax Parking.
  • Accessory dwelling units are in § 17.048.010. See Fairfax ADUs.
  • “Discretionary approvals” are defined to include use permits, variances, design review, grading permits, tentative maps, and master plans (§ 17.056.020). See Fairfax Design Review.

Zoning district families

Fairfax uses a compact but varied set of base zones, plus overlays and planned development tools:

• Residential
  • RS‑6 and RS‑7.5 — single‑family residential districts; RS‑6 standards include slope‑based minimum site area and height (§ 17.012.060; § 17.080.050; § 17.080.060).
  • RD 5.5–7 — residential district mapped at § 17.012.070 (uses/standards not provided in source materials).
  • RM — multiple‑family residential (uses, yards, parking, height, driveway standards in Chapter 17.088; e.g., § 17.088.030; § 17.088.060; § 17.088.070).
  • RM‑S — multiple‑family residential—senior (Chapter 17.090; e.g., § 17.090.070; § 17.090.080; § 17.090.100).
• Commercial and mixed
  • CL, CH, CC, CS — mapped commercial districts (§§ 17.012.090–.120; standards not provided in source materials).
  • CR — commercial recreation; all structures and exterior changes need design review and must comply with parking and sign rules (§ 17.108.020; § 17.108.060).
• Special purpose and planned districts
  • O‑A and UR — mapped districts (§ 17.012.150; § 17.012.160; standards not provided in source materials).
  • PDD/PD and the SF‑RMP (single‑family residential master plan) framework — planned development tools with density set at zoning, tied to site constraints and the General Plan (§ 17.012.140; § 17.012.170; § 17.116.060).
• Overlays/combining districts
  • HRD overlay — hillside residential development standards and optional clustering (§ 17.072.090). See Fairfax Overlay Districts.
  • A Agricultural & Conservation District — combining overlay that supersedes conflicting base rules where applied (§ 17.120.010).
  • WHO‑A/WHO‑B — mapped overlays (§ 17.012.165; standards not provided in source materials).

Citywide development standards

At a high level, Fairfax balances hillside safety, creeks, and neighborhood scale:

• Site area and slope (single‑family)
  • The RS‑6 minimum site is 6,000 sq ft and 60 ft wide for slopes ≤10%. Above 10% slope, area increases by 300 sq ft per each 1% up to 15%, and steeper than 15% increases by 1,000 sq ft and 3 ft width per each 1% (§ 17.080.050).
  • On certain pre‑1970 “irregular lots of record,” a single‑family home may be built if it meets coverage/height/setbacks and the owner holds no contiguous property (§ 17.044.030).
• Height
  • In RS‑6, principal buildings are capped at 28.5 ft and 2 stories on slopes ≤10%; on steeper lots: 35 ft downhill, 28.5 ft uphill, up to 3 stories (§ 17.080.060(A)).
  • In RM, the same 28.5 ft baseline applies; on steeper lots: 35 ft downhill, 28.5 ft uphill; density bonus projects may reach up to 36 ft with an extra step‑back story (§ 17.088.060(A)(2)).
  • In RM‑S, height mirrors the slope‑based 28.5–35 ft pattern; no building may exceed 3 stories (§ 17.090.070).
  • Accessory structure heights are typically 15–16 ft depending on district (§ 17.080.060(B); § 17.088.060(B); § 17.090.070(B)).
• Setbacks, lot coverage, and creeks
  • Town‑wide provisions organize lot coverage and setbacks, with tailored rules for sidewalk setbacks in commercial/industrial areas and creek‑adjacent development (§ 17.040.010; § 17.040.020; § 17.040.030; § 17.040.040). District‑specific yards for multi‑family live in RM and RM‑S (§ 17.088.070; § 17.090.080).
• Parking
  • Base off‑street parking ratios live in Chapter 17.052 (referenced in § 17.126.070 and § 17.072.090(F)(3)); mixed‑use projects can request reductions for shared parking, transit proximity within 400 ft, or demonstrated demand, and affordable projects may seek modified dimensions based on density bonus eligibility (§ 17.126.070(A)(1)–(4)).
  • Location/design rules include: multi‑family spaces within 150 ft of units; covered parking near the front half for projects >20 du/ac; deeper setbacks/screening for uncovered spaces on larger sites (§ 17.126.070(B)(1)–(2)).
• Traffic and circulation
  • Fairfax uses an “acceptable” LOS D at principal signalized intersections; discretionary approvals can trigger traffic review/permits in certain districts (§ 17.056.020; see “Traffic impact permit” in RM at § 17.088.100).

See also Fairfax Development Standards and Fairfax Parking.

Specific plans & overlays

HRD overlay — Hillside Residential Development

Projects in the HRD overlay must meet objective standards addressing fire, geologic hazards, grading, ecology, landscaping, and circulation (§ 17.072.090):

• Fire and geologic safety: comply with the Fire Code; prohibit building on known slides/springs/faults absent acceptable geotechnical approvals (§ 17.072.090(A)–(B)).
• Grading and timing: contour slopes; typical cut/fill not steeper than 1:1.5 without approval; no initial grading Oct 1–Apr 1; minimize retaining wall height with integrated materials/planting (§ 17.072.090(C)).
• Ecology and riparian: avoid rare habitat; require tree permits under Chapter 8.28; no development within 50 ft of the high‑water centerline on either side (§ 17.072.090(D)).
• Landscaping: comply with the state Model Water Efficient Landscape Ordinance (MWELO) for ≥500 sq ft of new landscape; prescriptive option for ≤2,500 sq ft; encourage fire‑ and drought‑resistant species (§ 17.072.090(E)).
• Circulation/parking: meet Town Engineer and Fire Code street standards; require guest/public parking as needed; conform to Chapter 17.052 parking (§ 17.072.090(F)).
• Design: projects must meet Fairfax’s design criteria (§ 17.020.040) as referenced in § 17.072.090(G).

Low‑impact clustered development option (sites >1 acre with average slope >15% in the Housing Element):

• Density formula: MN = site area / (10,000 + 1,200 per 1% over 15% slope) (§ 17.072.090(H)(1)).
• Minimum lot sizes may be reduced if overall density stays within General Plan maximum (§ 17.072.090(H)(2)).
• Gross habitable area cap: 3,500 sq ft per unit; garage area >500 sq ft counts toward the cap (§ 17.072.090(H)(3)).
• Streets/driveways: grades up to 18% (up to 25% with approvals); durable non‑asphalt surfaces >15%; grooved surfaces >18% (§ 17.072.090(H)(4)).
• Emergency access: at least two ways in/out for 5+-lot clusters (§ 17.072.090(H)(5)).
• Building design: roof/pitch variation, facade articulation; avoid long flat rooflines >40 ft; provide 200 cu ft lockable storage per unit (§ 17.072.090(H)(6)).

Planned development and SF‑RMP

For planned development and single‑family residential master plan projects, the Planning Commission sets a density consistent with the General Plan and site constraints (geology, safe building area count, and cumulative drainage/circulation impacts) (§ 17.116.060(C)). Minimum area for a planned development is generally 4 acres, unless the Commission finds a smaller site appropriate (§ 17.116.060(A)).

A Agricultural & Conservation combining district

Where combined with RS‑7.5, RS‑6, or PD, the A district’s regulations govern any conflicts with base district standards (§ 17.120.010).

See Fairfax Overlay Districts.

Building permits & review

• Design review is often the gatekeeper. Applications are filed on Planning Commission forms with plans/elevations and other information needed to apply the design criteria (§ 17.020.050). The Commission decides conformity with § 17.020.040 criteria and applicable objective standards; approvals become effective after 10 days unless appealed (§ 17.020.080). If design review is required, Fairfax will not issue a building permit or business license until approval is granted (§ 17.020.120).
• “Discretionary approvals” include use permits, variances, design review, grading permits, tentative maps, and master plans (§ 17.056.020). Combined reviews are typical—projects needing design review and other permits are heard together (§ 17.020.080(D)). See Fairfax Design Review and Fairfax Variances and Exceptions.
• Commercial recreation (CR) projects: all structures and exterior changes are subject to design review, and any use permit runs with/conditions the design approval (§ 17.108.020; § 17.108.060).
• Parking adjustments: mixed‑use or affordable projects can seek shared/transit‑based reductions or modified dimensions with documented studies and findings (§ 17.126.070(A)–(B)).
• Accessory dwelling units (ADUs/JADUs): reviewed ministerially—no hearing/preference—on a 60‑day shot clock after a complete application; completeness must be determined within 15 business days; Fairfax offers a 50% fee reduction incentive through January 1, 2036 (§ 17.048.010(D)(1)–(3)).
• Building code: construction must also comply with the California Building Standards Code.
• Traffic impact permits: certain zones (e.g., RM) list a traffic impact permit requirement (§ 17.088.100; see also § 17.120.060 in A district table of contents).

State housing law in Fairfax

• ADUs/JADUs
  • Fairfax implements state ADU law by ensuring compliant ADUs/JADUs are ministerially approved and not counted against density or deemed inconsistent with the General Plan or zoning (§ 17.048.010(B), (D)). A JADU is capped at 500 sq ft and must be within a single‑family structure, with specific kitchen/bath options (§ 17.048.010(C)).
• Density bonus
  • The RM district explicitly offers extra height (up to 36 ft) and an additional step‑back story for density‑bonus projects with affordable units, with broader density‑bonus provisions referenced in Chapter 17.050 and Government Code § 65915 (§ 17.088.060(A)(2); § 17.126.070(A)(4)(a)). See California housing laws.
• SB 9 (urban lot split/duplex) and local rent rules
  • Not found in source materials. Verify with the jurisdiction for SB 9 procedures and any rent stabilization/just‑cause provisions.
• Conversions
  • Fairfax flags “condominium conversion prohibited” among its general regulations (Chapter 17.040; § 17.040.090 in chapter list). Confirm applicability and any exceptions with the Planning Department.

See also Fairfax Land Use and Fairfax ADUs.

Information Gaps

• Numeric setback, lot coverage, FAR values by district, and base parking ratios are not included in the source materials here (though organized in Chapter 17.040, district “Yards” sections, and Chapter 17.052 respectively). Verify current numbers with the Town’s codified Title 17.
• Standards for CL/CH/CC/CS, O‑A, UR, and WHO overlays are not included in the source materials. Confirm before proceeding with site planning.
• SB 9 procedures and any local rent/tenant protections are not provided in the source materials.

Source References

• Zoning map and districts: § 17.012.020; § 17.012.040; § 17.012.060; § 17.012.070; §§ 17.012.080–.180
• Compliance with regulations: § 17.004.140
• General zone regulations (lot coverage, setbacks, sidewalks, creeks, permit timing): Chapter 17.040 (e.g., § 17.040.010; § 17.040.020; § 17.040.030; § 17.040.040; § 17.040.110)
• RS‑6 standards: § 17.080.050; § 17.080.060
• RM standards: Chapter 17.088 (e.g., § 17.088.030; § 17.088.060; § 17.088.070; § 17.088.100)
• RM‑S standards: Chapter 17.090 (e.g., § 17.090.070; § 17.090.080; § 17.090.100)
• HRD overlay standards: § 17.072.090
• Planned development/SF‑RMP: § 17.116.060
• A Agricultural & Conservation combining district: § 17.120.010
• Design review procedures and enforcement: § 17.020.050; § 17.020.080; § 17.020.120
• Discretionary approvals/traffic definitions: § 17.056.020
• Parking modifications and design/location: § 17.126.070
• ADUs/JADUs: § 17.048.010
• Commercial recreation requirements: § 17.108.020; § 17.108.060
• Irregular lots: § 17.044.030