San Mateo Zoning, Planning & Building Codes

Last reviewed: July 3, 2026

Overview

San Mateo’s land-use law is codified in the San Mateo City Zoning Code (Title 27 of the Municipal Code), organized as chaptered rules for general provisions, district regulations, special districts and overlays, and procedural chapters that govern review bodies and permit processing (see the planning‑process chapters and district chapters listed below). Key citywide standards — setbacks, yards, floor‑area ratio, lot coverage and parking — are set by district chapters and by cross‑referenced chapters (building, fire and parking chapters). The City operates a mix of base zoning districts (residential, commercial, industrial), overlay districts (for senior housing, residential overlay, qualified overlay areas) and several specific plans (for Bay Meadows, Hillsdale Station, the Rail Corridor TOD) that can supersede or refine Title 27 where they apply. For users: the most important code locations to read first are the procedural chapters that define review bodies and application types, the SB 9 / Two‑Unit chapter, the residential and commercial district chapters, and the specific plan chapters listed below. § 27.02.170; § 27.06.040; § 27.21.070.

How San Mateo's code is organized

• Title: the San Mateo City Zoning Code is carried in Title 27. District and program rules are organized by chapter numbers (for example, general provisions and definitions, boards & commissions, district chapters, special districts and specific plan districts). See how the code uses chapter headings and cross‑references to locate rules. § 27.02.040; § 27.02.170.
• Review bodies and procedures: the City uses a mix of ministerial review, administrative/site plan review, Planning Commission and City Council action. The Development Review Board reviews applications and makes recommendations (§ 27.06.030); the Planning Commission has final review authority on larger or discretionary projects and appeals (§ 27.06.040). Thresholds for Site Plan and Architectural Review (SPAR) and other review triggers are listed in § 27.06.040(a)(3).
• Cross‑references: specific plans and special districts commonly state that their provisions govern where they conflict with the base code — e.g., the Rail Corridor / TOD rules expressly take precedence where they differ (§ 27.90.070).

(Quick links you’ll want while reading: the page mentions city rules for development standards, parking, design review, overlays, ADUs, and the California building code. Use the City’s topic pages as you read: development standards parking design review overlay districts ADUs California Building Standards Code.)

Zoning district families (city‑wide view)

San Mateo’s Title 27 separates use and bulk rules into district chapters. Representative district families and where they live in Title 27 include:

• Residential districts — examples and rules:
  • R‑1 / R family standards and single‑family yard rules are located in the R chapters (see the R‑district yard tables and single‑family provisions). Rear‑yard and side‑yard standards for many residential districts appear in the R chapter text: for example, a 15‑foot rear yard minimum and other rear‑yard rules are set out in § 27.18.090; front/side projection allowances are in § 27.18.100. § 27.18.090; § 27.18.100.
  • The Residential Overlay (/R, /R4, /R5) is a mixed‑use overlay to encourage residential in commercial areas; its purpose and allowed densities are in Chapter 27.29 (see § 27.29.100—§ 27.29.116 for /R overlay land, density, FAR and setback rules). § 27.29.100; § 27.29.106; § 27.29.110; § 27.29.116.
• Commercial districts — examples:
  • C1 (Neighborhood Commercial) purpose and permitted uses are in § 27.30.005 and § 27.30.010; El Camino Real frontage has special build‑to and setback rules in § 27.30.070. § 27.30.005; § 27.30.010; § 27.30.070.
  • The Central Business District (CBD) and downtown bulk/height controls are implemented through downtown‑specific chapters (see the CBD references in the Residential Overlay chapter and the downtown Building Height and Bulk chapter). § 27.29.112(b).
• Special and site‑specific districts:
  • S (Shoreline / Bayfront) district standards (public access, performance standards, FAR limit of 1.0 and required buffers) are in Chapter 27.59 (see § 27.59.040—§ 27.59.080). § 27.59.040; § 27.59.050; § 27.59.070; § 27.59.080.
  • Specific Plans / Planned Areas: The City codifies several site‑specific plans as separate chapters that govern uses and standards within their boundaries, for example the Bay Meadows Specific Plan (BMSP) (Chapter 27.88) and the Hillsdale Station Area Plan (Chapter 27.92). Each specific plan chapter says its rules govern within the plan area except where it defers to the Zoning Code (see § 27.88.010—§ 27.88.050 and § 27.92.010—§ 27.92.050). § 27.88.010; § 27.88.050; § 27.92.010; § 27.92.050.
  • Transit‑Oriented Development (TOD) areas along the rail corridor are regulated by the TOD chapter (Chapter 27.90) which implements the Rail Corridor Plan and may require specific plans for TOD parcels (§ 27.90.010—§ 27.90.070). § 27.90.010; § 27.90.020; § 27.90.050; § 27.90.070.
• Overlay and qualified districts:
  • Senior Citizen Overlay (SC) rules — how SC is applied and the allowed underlying zones are in § 27.61.010—§ 27.61.040. § 27.61.010; § 27.61.020; § 27.61.030.
  • Qualified Overlay (Q6, Q7, Q8) limitations and conditions (special use permit requirements, site plans, FAR caps) are included in the Q‑overlay text; Q‑districts impose site‑specific master plan compliance and special use requirements (see the Q7 and Q8 limits and FAR caps described in the Q‑overlay text). § 27.60.160 (cross‑references) and Q overlay descriptions.

Citywide development standards (high level)

• Setbacks & yards: district chapters set front, side and rear yard minima for each district; examples include a 20 ft front yard in a particular R6 district standard (§ 27.28.084) and 15 ft side yards and 25 ft rear yards for larger multiple‑family districts (§ 27.28.086; § 27.28.088). § 27.28.084; § 27.28.086; § 27.28.088.
• Height and bulk: where applicable buildings must comply with the General Plan Building Height Plan or downtown height/bulk chapters; overlay and specific plan chapters reference the Building Height Plan and downtown bulk chapter (see § 27.29.112 and § 27.59.070). § 27.29.112(b); § 27.59.070.
• Floor Area Ratio (FAR) and lot coverage: district chapters state maximum FAR (for example, some overlay and special districts list explicit FAR caps — see Q‑overlay FAR caps and the S district FAR of 1.0) and parcel coverage limits are given in certain district texts (e.g., coverage limits and district FAR rules in Chapter 27.28 and Q overlay caps). § 27.28.080; § 27.59.080; Q‑overlay FAR rules.
• Parking: off‑street parking requirements are administered through Title 27 parking chapters; the shoreline, specific plans and other chapters cross‑reference Chapter 27.64 for parking and loading, and specific exemptions are listed (for example, the code exempts certain right‑of‑way displays and public seating from parking requirements in § 27.87.040). § 27.59.050; § 27.87.040.
  • See the City’s practical parking guidance at the parking page.

Notes on interpretation: where a specific plan or overlay applies, its rules will govern in case of conflict with the general Zoning Code (see the Rail Corridor Plan / TOD relationship to Title 27). § 27.90.070.

Design & discretionary review

• Thresholds for discretionary review: projects meeting the thresholds in § 27.06.040 (for example projects over certain unit counts, non‑objective design triggers, projects over 10,000 sq ft non‑res) require Planning Commission review and SPAR. § 27.06.040(a)(3).
• Minor design review and Single‑Family Dwelling Design Review exist for smaller residential changes; the SB 9 / Two‑Unit chapter references SFDDR and SPAR for larger SB 9 units or where an 800‑sq‑ft limit is exceeded (§ 27.21.070(b)(2)). § 27.21.070(b)(2).
• Objective design standards: where state law requires ministerial, objective review (SB 9, ADU streamlining), the City requires compliance with its adopted Objective Design Standards and interim objective standards as adopted by Council resolution (see the SB 9 chapter requirement that ministerial developments meet Interim Objective Design Standards). § 27.21.030(f); § 27.21.070(f).

(If you want a step‑by‑step on design review thresholds, start at § 27.06.040 and then check the district chapter for any project‑specific SPAR triggers. § 27.06.040.)

Specific plans & overlays (what overrides what)

• Specific plans codified in Title 27 (examples):
  • Bay Meadows Specific Plan (BMSP) — Chapter 27.88 says the Bay Meadows Specific Plan governs within its boundaries and may supersede or supplement Title 27 (see § 27.88.010—§ 27.88.050). § 27.88.010; § 27.88.050.
  • Hillsdale Station Area Plan — Chapter 27.92 describes purpose, boundary and how uses and conditions are applied (see § 27.92.010—§ 27.92.050). § 27.92.010; § 27.92.050.
  • TOD / Rail Corridor Plan — Chapter 27.90 implements the Rail Corridor TOD Plan and explicitly states the Rail Corridor Plan will govern in conflicts with the Zoning Code. § 27.90.010; § 27.90.070.
• Overlays and qualified districts:
  • Residential Overlay (/R, /R4, /R5) regulates mixed‑use and residential density in commercial areas; see Chapter 27.29 for density, FAR and setback adjustments (§ 27.29.100—§ 27.29.116). § 27.29.100; § 27.29.106; § 27.29.112.
  • Senior Citizen Overlay (SC) superimposes on eligible zones and allows development under SC regulations when a special use permit is approved (§ 27.61.010—§ 27.61.040). § 27.61.010; § 27.61.020.
  • Qualified Overlays (Q6, Q7, Q8) are site‑specific and carry bespoke FAR, parking and special use permit conditions (see the Q‑overlay limitation descriptions). Q‑overlay entries set explicit FARs and special permit requirements. Q‑overlay text and qualified conditions appear in the special district/overlay chapters.

For a plain‑English walk through overlays and where they apply see the City’s overlay districts page.

Building permits & review — practical path

• Two parallel permit streams:
  1. Ministerial / objective approvals: certain state‑streamlined projects (SB 9 two‑unit development, ministerial ADUs per state law) are processed ministerially with objective standards and no discretionary hearing. San Mateo’s SB 9 chapter requires ministerial processing where the project complies with the Chapter’s objective standards and expressly states ministerial SB 9 approvals are not appealable (§ 27.21.030(a)(2); § 27.21.030(c)). § 27.21.030(a)(2); § 27.21.030(c).
  2. Discretionary review: projects that exceed ministerial thresholds (large projects, special use permits, planned developments, SPAR triggers) go through administrative or Planning Commission review as specified in § 27.06.040 and the application procedures (cross‑reference to § 27.08 application processing). § 27.06.040; § 27.08.040 (referenced).
• Submittal requirements and processing:
  • SB 9/Urban Lot Split applications must include owner affidavits, full site surveys, maps, plans and other checklists; the Urban Lot Split article details specific documents required for split recordation and ministerial review (§ 27.21.110; § 27.21.030(d)). § 27.21.110; § 27.21.030(d).
  • The code requires compliance with the California Building Code, Fire Code, and local fire sprinkler ordinance for all development — these building/permitting standards are separate but mandatory (see the SB 9 chapter’s cross‑reference to state codes). § 27.21.030(g).
• Appeals & final actions: the Planning Commission’s actions are appealable to Council in specified circumstances; ministerial SB 9 decisions explicitly are not appealable (§ 27.06.040; § 27.21.030(c)). § 27.06.040; § 27.21.030(c).

For building‑code details you’ll also need to consult the California Building Standards Code.

State housing law in San Mateo (how ADU, SB 9, density bonus, etc. fit)

• SB 9 / Two‑Unit & Urban Lot Splits: San Mateo implemented a Two‑Unit Development chapter to comply with SB 9; the City sets specific objective development standards (setbacks, heights, parking rules) for SB 9 units and processes qualifying applications ministerially (see the Two‑Unit Development standards in § 27.21.070 and the ministerial processing rules in § 27.21.030). SB 9 minimums (e.g., 4‑ft side/rear setbacks and one off‑street parking space unless a statutory exemption applies) are reflected in the chapter and the City incorporates state‑required exemptions for transit proximity and car‑share proximity (§ 27.21.070(d)–(e)). § 27.21.070; § 27.21.030.
• Accessory Dwelling Units (ADUs): the Zoning Code cross‑references California ADU law and requires compliance with the California Building Code; the SB 9 chapter also directs that ADU/JADU and ministerial unit development comply with state law and local objective standards where applicable. For the City’s ADU process see the local ADU chapter and the City ADU guidance; local code also defers to state ADU rules where Title 27 would otherwise be preempted. § 27.21.030(g); see ADU‑related cross‑references.
  • See the City’s ADU topic page for local step‑by‑step ADU guidance: ADUs.
• Density bonus / affordable housing incentives: planned developments, specific plans and the residential overlay provide mechanisms to allow greater density and FAR when certain findings are met or when a specific plan authorizes it (see the Residential Overlay § 27.29.110 on FAR allowances and planned development chapters). § 27.29.110; § 27.62 (planned development procedures).
• Interaction with state law: where state housing law requires ministerial processing or preempts local controls, the City’s chapters for SB 9 and other state‑driven programs implement those state standards while still requiring compliance with objective local technical standards (e.g., building code, fire code). See the SB 9 chapter’s statement that objective local standards shall not preclude two units of at least 800 sq ft unless specific adverse impacts are found (§ 27.21.070(b)(1)–(3)). § 27.21.070(b).

Source References

• San Mateo Zoning Code — Two‑Unit / SB 9 chapter and ministerial processing rules: § 27.21.030; § 27.21.070.
• San Mateo Zoning Code — Planning bodies, Development Review Board and Planning Commission jurisdiction: § 27.06.030; § 27.06.040.
• San Mateo Zoning Code — Residential Overlay (mixed‑use residential), density and FAR: Chapter 27.29 (e.g., § 27.29.100; § 27.29.106; § 27.29.110).
• San Mateo Zoning Code — C1 Neighborhood Commercial and El Camino Real build‑to/setback rules: § 27.30.005; § 27.30.070.
• San Mateo Zoning Code — Shoreline / S district standards: Chapter 27.59 (e.g., § 27.59.040; § 27.59.050; § 27.59.070).
• San Mateo Zoning Code — Bay Meadows Specific Plan chapter: Chapter 27.88 (e.g., § 27.88.010—§ 27.88.050).
• San Mateo Zoning Code — Transit‑Oriented Development and Rail Corridor Plan: Chapter 27.90 (e.g., § 27.90.010—§ 27.90.070).

Information Gaps / Practical next steps

• A complete, line‑by‑line table of all R‑district numeric height, setback and FAR values across every residential subdistrict (R‑1, R1‑B, R3, R4, R5, R6‑D, etc.) was not fully extracted here; consult the City’s full Title 27 text or the district chapter pages to confirm the exact numeric limits for a particular parcel. Verify district‑specific numeric limits in the district chapter that governs your address. Not found in retrieved materials (see district chapters in Title 27).
• For permit timing, fees and submittal checklists (exact forms, engineering standards and Public Works “Standard Drawings and Specifications”), consult the City’s Planning Department submittal pages and the referenced City resolutions (those operational materials are cross‑referenced in Title 27 but not reproduced here). See § 27.21.030(d) for required SB 9 submittal items.