Local zoning · San Mateo

San Mateo — Variances and Exceptions

Q: What is the difference between a variance and a reasonable accommodation in San Mateo?

A variance is discretionary relief tied to hardship under Chapter 27.78 ; a reasonable accommodation is a distinct process for housing used by a person with disabilities with its own findings and shorter procedural timeline under Chapter 27.79 — the two are separate tracks and use different findings. § 27.78.010 and § 27.79.010–.040 .

Variances and Exceptions under the San Mateo local zoning and planning code, with the controlling citations.

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Last reviewed: July 2, 2026

Overview

Variances and exceptions in San Mateo are governed by Title 27 of the San Mateo Municipal Code (the Zoning Code). Variances are the formal, discretionary relief available when strict application of a zoning standard would cause hardship; exceptions and waivers (including reasonable accommodations and density-bonus waivers) are separate tracks with different findings and processing rules. For practical next steps see the city's San Mateo Zoning overview and the related rules on San Mateo Development Standards, San Mateo Parking, and San Mateo Design Review. § citations below are to Title 27 of the San Mateo Municipal Code as retrieved from the provided ordinance extract.

Core rules (what the code actually says)

Purpose: A variance exists so the approval body may “vary such provisions” of Title 27 when, owing to special conditions, enforcement would result in hardship; any variance may be conditioned so it does not become a special privilege. § 27.78.010
Findings / Conditions: The approval body must determine that the particular hardship criteria (listed in § 27.78.020) apply before granting a variance; the code explicitly ties variance relief to a showing of hardship and allows conditions to avoid injurious effects. The full list of the §'s subcriteria were not reproduced in all retrieved snippets; verify text of § 27.78.020 with the jurisdiction. § 27.78.020 — Verify with the jurisdiction.
Imposition of conditions: The Planning Commission (or designated approval body) may impose conditions “as may be necessary to prevent injurious effects” and to implement the code's purposes. § 27.78.030
Authorized variance types (limited list): Variances may only be granted for the enumerated items (examples include reduced yards/setbacks, reduction of build-to-lines, exceeding FAR limits, parking reductions/adjustments, allowing use on undersized lots subject to density ceilings, and minor increases in maximum parking distance). See the full list in § 27.78.040. § 27.78.040
Process entry points: A variance is a planning application type under the general rules; applicants file a planning application (PA) per the procedures in Chapter 27.08. § 27.08.010 (planning application submittal)
Reasonable accommodation / exceptions for disability: Separate from a variance, the City provides a streamlined “reasonable accommodation” (for residential uses serving persons with disabilities) with its own findings, application rules, timeframes, and appeal rights — see Chapter 27.79 (purpose, definitions, application, findings and appeals). § 27.79.010 and § 27.79.040–.050
Waivers & density-bonus related modifications: Requests to waive or modify development standards associated with density bonus or state density-bonus law follow Chapter 27.15 (including § 27.15.050 and § 27.15.060) and include specific submittal requirements and grounds for denial tied to Government Code 65915. § 27.15.050 and § 27.15.060
Specific exceptions (example — fences): The Zoning Administrator may grant an exception to fence height/location rules when (a) the fence is in scale with the neighborhood, (b) granting it won’t be materially detrimental to public health/safety/welfare, and (c) it is consistent with the General Plan. § 27.84.020

District-by-district breakdown (where variances/exceptions typically matter)

Below are San Mateo districts where variance/exception practice is commonly applied. Each subsection lists district purpose, typical permitted uses (decision-relevant), key dimensional standards that variance requests often target, and where the district applies in the code.

R-1 / Single‑Family Residence districts (R1-A, R1-B, R1-C)

Purpose: Preserve single-family neighborhoods; development and bulk rules for single-family dwellings are set in Chapter 27.18. § 27.16.010 and Chapter 27.18
Typical permitted uses: single‑family dwellings, accessory buildings, very limited home-occupations; some accessory plumbing/uses require special permits. See Chapters 27.16 and 27.18. § 27.18.030
Key dimensional standards commonly implicated in variance requests:
- Rear yard: 15 ft (new construction above one story: 25 ft) — § 27.18.090
- Street-side yard (corner lot): 15% of lot width, not less than 7.5 ft (R1‑A limit up to 25 ft) and 15 ft in R1‑B/C for ground floors; garage setback rules apply — § 27.18. (street side yard rules)*
- Off‑street parking minima for single‑family: baseline 2 garage spaces, with added requirements for larger homes; required parking cannot be in a required front or side yard — § 27.18.110
Where it applies: Chapter 27.18 and cross references in Chapters 27.16 and 27.08. § 27.16.010 and § 27.18.110

R-3, R-4, R-5 and residential overlays (mixed/multi‑family)

Purpose & uses: Higher-density residential districts and overlay rules set floor area, setback, bulk, and use controls; mixed-use projects follow additional overlay requirements (see Chapter 27.29 and the residential overlay rules). § 27.29.110–.116
Typical variance issues: FAR exceedances, setback reductions, and exceptions to floor‑area limitations (variances are specifically limited to the categories listed in § 27.78.040). § 27.78.040

C-1 — Neighborhood Commercial

Purpose: Create and maintain neighborhood shopping compatible with adjacent residential uses. § 27.30.005
Typical permitted uses: small retail, personal services, limited office; special-use permit for some categories. § 27.30.010
Typical variance targets: setbacks and buffers bordering residential parcels, parking reductions/adjustments. Variance authority for parking adjustments is in § 27.78.040(e)–(g). § 27.78.040

C-2 — Regional / Community Commercial

Purpose: Major commercial centers with broader office/retail/residential mix. § 27.32.005
Typical uses: retail, hotels, medical offices, parking facilities and residential as allowed per R4 standards in mixed projects. § 27.32.010
Standards: FAR limits vary by subdistrict (e.g., C2-.5, C2-1, C2-2) — see § 27.32.050. Variances to FAR are only permitted under the limited authorization in § 27.78.040(c). § 27.32.050 and § 27.78.040

M-1 — Manufacturing / Performance standards

Purpose: Manufacturing performance (noise, smoke, odor) standards apply across zones; manufacturing districts must meet performance rules listed in § 27.02.090. Variance requests affecting performance standards are constrained by those cross‑references. § 27.02.090

Overlay districts and special areas (e.g., Two‑Unit Overlay / SB9, Qualified Overlay Q6–Q8)

Two‑Unit Overlay / SB9 (Chapter 27.21) implements the City’s objective rules for ministerial two‑unit approvals and includes specific submittal and deed‑restriction requirements; projects that do not meet the objective rules can be routed to discretionary design review/variance tracks. § 27.21.100–.140
Qualified Overlays (Q6, Q7, Q8) contain site‑specific conditions, special-use permit rules and modified development standards (e.g., discrete FAR or build‑to provisions); departures are evaluated under their own findings and the general variance rules if applicable. (See Q6–Q8 notes under the district chapters.) § 27.60. (Qualified Overlays)*

Quick-reference table: decision‑relevant rules (high‑level)

Topic	Key rule (plain)	Code reference
When variances exist	Relief for hardship where strict compliance causes hardship; approval body may condition approval.	§ 27.78.010
What a variance can do	Authorized only for items listed (reduced yards, FAR exceedance, parking reductions, use on undersized lots subject to density caps, etc.).	§ 27.78.040
Conditions on a variance	Planning Commission may impose conditions to prevent injurious effects.	§ 27.78.030
Reasonable accommodation	Separate process for disability accommodations with specific findings and appeals.	Chapter 27.79 (esp. § 27.79.010, § 27.79.040–.050)
Waivers for density bonus	Waivers/modifications for density‑bonus projects follow Chapter 27.15; specific documentation required and the City can deny under enumerated grounds.	§ 27.15.050–.060
Fence exceptions	Zoning Administrator can grant fence height/location exceptions if neighborhood scale, safety, and GP consistency are met.	§ 27.84.020

Application Checklist (what an applicant must supply)

A completed planning application (PA) using the City form (planning applications include variances) § 27.08.010
Accurate legal description, scaled site/site survey, dimensioned architectural drawings and elevations, landscaping and parking diagrams (typical PA submittal elements). § 27.08.010
A written statement documenting the claimed hardship and how the conditions in § 27.78.020 are satisfied (hardship analysis). § 27.78.020 — Verify full text with jurisdiction.
If the request affects parking, show how Chapter 27.64 rules are handled and quantify stalls to support a parking variance request. See San Mateo Parking. § 27.78.040(e) and Chapter 27.64
For reasonable accommodation requests: documentation of disability, scope of accommodation, alternatives considered, and the effects on City resources. See Chapter 27.79 and its submittal checklist. § 27.79.040–.050
For density-bonus waiver/modification requests: documentation showing standards physically preclude use of density bonus, cost documentation if incentives requested, and the specific waivers sought. § 27.15.050–.060
Fees as set by Council resolution (Chapter 27.12). § 27.12.010
Neighbor/notice requirements where applicable (SFDDR and some discretionary reviews require notice to neighbors; see SPAR/SFDDR rules). See San Mateo Design Review. § 27.08.030 and § 27.08.032

Risks & Ambiguities

Issue	Why it matters	What to verify
Hardship standard wording	Variances hinge on narrowly applied "hardship" findings; missing or ambiguous text in the extracted snippets means reliance on the full § text is necessary.	Read § 27.78.020 in full at the City code; confirm the specific subfactors the decision maker must find. § 27.78.020 — Verify with the jurisdiction.
Overlap with state density-bonus law	Waivers tied to density bonuses must comply with Government Code 65915; the City has specific denial grounds (e.g., special adverse impact, historic resources).	Verify interplay of § 27.15.050 with state law and whether the project qualifies as a “Covered Project.” § 27.15.050
SB 9 / Two‑Unit Overlay conflicts	SB9 ministerial paths and deed restrictions change the discretionary landscape; projects routed to discretionary review may lose ministerial streamlining.	Confirm whether the lot is subject to Chapter 27.21 Two‑Unit Overlay rules or is exempt (R1‑A/B/C exclusions). § 27.21.050–.130
Historic resources	Waivers or exceptions that affect properties on the California Register trigger additional denial grounds.	Check for historic listing; see § 27.15.050(b)(4) (adverse impact on California Register property). § 27.15.050
Parking reductions vs Chapter 27.64	Parking variances are allowed but the code limits how many stalls or dimensions can be modified; local parking policy and Downtown overlays may add constraints.	Cross-check § 27.78.040(e)–(g) and Chapter 27.64; consult the San Mateo Parking page. § 27.78.040
Applicability to single‑family vs multi‑family	Some variance actions (and appeals) are routed differently depending on whether the structure is single‑family or multi‑family; see review jurisdiction rules.	Verify review body per § 27.06.040(a)(9) and SPAR/SFDDR exemptions. § 27.06.040 and § 27.08.030

Plain‑English summary

If your project can't meet a particular San Mateo zoning rule because of special physical conditions of the parcel, you can ask for a variance — but the City only grants those for specific items (yards, FAR, parking, etc.), and you must convince the approval body there is a true hardship and that the change won't harm neighbors; separate, narrower “exceptions” exist for fences, disability accommodations, and density‑bonus waivers with their own submittal lists and findings. §§ 27.78.010–.040, 27.84.020, 27.79.010, 27.15.050–.060

Source References

San Mateo Municipal Code, Title 27: Variances chapter — § 27.78.010, § 27.78.020, § 27.78.030, § 27.78.040.
San Mateo Municipal Code, Chapter 27.08 (Planning application procedures) — § 27.08.010, § 27.08.030.
San Mateo Municipal Code, Chapter 27.79 (Reasonable accommodation for residential uses) — § 27.79.010 and application/appeals § 27.79.040–.050.
San Mateo Municipal Code, Chapter 27.15 (Density bonus / waivers and modifications) — § 27.15.050, § 27.15.060.
San Mateo Municipal Code, Chapter 27.84 (Fences) — § 27.84.020 (exceptions).
San Mateo Municipal Code, Chapter 27.18 (R‑1 rules and bulk/parking standards) — rear yard, street side yard, parking minima § 27.18.090, § 27.18. (street side rules)*, § 27.18.110.
San Mateo Municipal Code, Chapter 27.30 and 27.32 (C‑1 and C‑2 permitted uses and FAR rules) — § 27.30.005, § 27.30.010, § 27.32.005, § 27.32.010, § 27.32.050.
San Mateo Municipal Code, Chapter 27.21 (Two‑Unit Overlay / SB9 rules) — § 27.21.100–.140.

If you need the verbatim text of any cited § or help preparing the hardship narrative or required exhibits, tell me the parcel APN or address and I’ll point to the exact subsections to quote and the typical supporting diagrams City staff expect. Verify parcel‑specific rules with City staff before submittal.

Sources

Retrieved passages

San Mateo Zoning Code (section 65915) High relevance
San Mateo Zoning Code (chapter shall) High relevance
San Mateo Zoning Code (Title 23) High relevance
San Mateo Zoning Code (Section 27.08.030) High relevance
San Mateo Zoning Code (Title may) Medium relevance
San Mateo Zoning Code (Title and) Medium relevance
San Mateo Zoning Code (Section 23.40) Medium relevance
San Mateo Zoning Code (Section 65915) Medium relevance
CFC § 1 (Section 2155) Medium relevance
San Mateo Zoning Code (§ 8) Medium relevance
San Mateo Zoning Code (Chapter shall) Medium relevance
San Mateo Zoning Code (Title 26) Medium relevance
San Mateo Zoning Code (Chapter 27.40) Medium relevance
San Mateo Zoning Code (Chapter 27.74.) Medium relevance

Cited sections

Official San Mateo code library

Frequently asked questions

What kinds of zoning relief can I get in San Mateo if my backyard setbacks make a second‑story addition impossible?

The City allows variances to permit a yard of less dimension than required (i.e., setback relief) when the approval body finds the hardship criteria are met; such requests are processed as a planning application and can be conditioned to avoid injurious effects. See § 27.78.040(a) and § 27.78.010 for the variance authority and purpose.

What is the difference between a variance and a reasonable accommodation in San Mateo?

A variance is discretionary relief tied to hardship under Chapter 27.78; a reasonable accommodation is a distinct process for housing used by a person with disabilities with its own findings and shorter procedural timeline under Chapter 27.79 — the two are separate tracks and use different findings. § 27.78.010 and § 27.79.010–.040.

Can I ask for fewer parking stalls as part of a variance?

Yes — the code authorizes variances to reduce required off‑street parking or adjust stall dimensions, subject to the limitations and findings in § 27.78.040(e)–(g) and Chapter 27.64 (off‑street parking rules). Document parking demand and alternatives in your PA. § 27.78.040(e) and Chapter 27.64.

If my project uses the state density bonus, can the City deny requested development‑standard waivers?

The City may deny a waiver or modification of development standards for density‑bonus projects under the denial grounds listed in § 27.15.050(b) (e.g., failure to show physical preclusion, specific adverse impacts, historic resource impacts); applicants must submit supporting documentation as required in § 27.15.060. § 27.15.050–.060.

Are fence height exceptions processed as variances?

No — fence height/location exceptions are handled by the Zoning Administrator per the fence‑specific exception procedure; they require findings about scale, public health/safety, and consistency with the General Plan under § 27.84.020 rather than the general variance findings. § 27.84.020.

Who decides variance appeals in San Mateo?

Appeals follow the planning‑decision appeal procedure; decisions coming from the Zoning Administrator can be appealed to the Planning Commission and then to the City Council per the appeals rules in the code (see § 27.06.040 and the appeals procedures referenced in Chapter 27.08). § 27.06.040 and § 27.08.

Can SB9 / Two‑Unit Overlay projects get variances?

Projects that meet objective SB9/Two‑Unit Overlay standards are ministerial; if a project does not meet those objective standards (or is ineligible under the Chapter's exemptions such as certain R1‑A/B/C lots), the project may be subject to discretionary review where variance requests would follow the usual Title 27 procedures. See Chapter 27.21. § 27.21.045 (discretionary review alternative) and related sections.

If my property is on the California Register, does that affect waiver/variance chances?

Yes. The City may deny a waiver or reduction if it would have an adverse impact on any real property listed in the California Register of Historical Resources; that is an explicit denial ground in the density‑bonus waiver rules and informs review of other site‑specific relief. § 27.15.050(b)(4).

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