City program

Pre-Approved ADU Plans in San Mateo, California

Browse official and accepted pre-approved ADU plans for San Mateo, California. Compare plan size, bedrooms, providers, approval status, official source links, permit requirements, and fees.

Program status: source-backed listings Last checked Jul 28, 2026

Program Overview

This San Mateo page summarizes source-backed pre-approved ADU plan listings for San Mateo, California, using official records tied to City of San Mateo, City of San Mateo / Community Planning Collaborative, and Community Planning Collaborative. The current export lists 17 accepted plans from 8 providers; provider names include Adore Homes, Abodu, LiveLarge Home, and others. The accepted listings are tied to the local San Mateo program. Plan records cover 340 to 1,110 sq ft and studio to 2 bedrooms where those fields were listed by the source.

Permit and fee context is kept separate from plan acceptance. The data export includes 18 permit requirement records and 9 fee records for San Mateo. Permit requirement records include Phase 2 site-specific permit review, No modifications in streamlined path, and others. Fee records include AB 1332 plan review to add a plan to the City gallery, Eligible manufactured, prefab, or pre-approved ADU permit, and others. When a source did not publish a value, the page keeps that field as Not listed in source instead of filling a blank.

Use these listings as a starting point for matching a plan to a property. Source links, checked dates, acceptance notes, and provider records are shown so you can verify whether a plan remains accepted locally, what site-specific review remains, and whether local fees, plan licensing, or provider terms apply. A listing in this directory does not guarantee permit approval for a specific parcel.

Summary

Location
San Mateo, San Mateo County, California, USA
Accepted plans
17 accepted plans
Providers
8 providers
Origin programs
1 program
Plan size range
340 to 1,110 sq ft
Permit sources
27 sources

How to use this page

  1. Pick a plan size and bedroom count.
  2. Check whether the plan originated locally or is accepted from another city/county program.
  3. Open the official source.
  4. Confirm current status with the local building department.
  5. Ask the provider what site-specific work, plan licensing, engineering, and utility review are still required.

Accepted Plans

17 plans

Permit Requirements

18 requirements

Site specific

Phase 2 site-specific permit review

Government PDF

Applicant must add property-specific information and submit through the Online Permit Center; pre-approval does not guarantee a permit.

Last checked
Jul 28, 2026
Notes
City retains final planning and building authority for each parcel.

Site specific

Program zoning and hazard eligibility

Government PDF

The parcel must be residentially zoned and outside the guide's High Hazard FEMA flood and WUI exclusions.

Last checked
Jul 28, 2026
Notes
A provider's WUI feature claim does not override the City's program eligibility screen.

Site specific

Code enforcement and buildable-area eligibility

Government PDF

The project may not use the streamlined path where active code enforcement affects the project or the location is non-buildable or within an easement.

Last checked
Jul 28, 2026
Notes
Not listed in source

Site specific

Site-plan content

Government PDF

Submit parcel, zoning, area, parking, tree, landscape, hazard, soil-disturbance, utility, easement, topography, setback, fire-separation, and related site information.

Last checked
Jul 28, 2026
Notes
The guide's checklist should be consulted for the complete current submittal set.

Manufactured

HUD manufactured foundation evidence

Government PDF

Foundation plans require HUD or HUD-approved Production Inspection Primary Inspection Agency evidence, or preparation by a California-licensed engineer.

Last checked
Jul 28, 2026
Notes
Omitted site-specific foundation information must be supplied during Phase 2.

Detached

Detached ADU height

Official city source

Maximum 18-foot plate height and 24-foot peak height, subject to current code conditions.

Last checked
Jul 28, 2026
Notes
This supersedes the older 16-foot figure in the 2025 general handout where inconsistent.

Detached

Utility connections

Official city source

Conversions do not require a new or separate utility connection; new detached ADUs may require one with proportional connection or capacity charges.

Last checked
Jul 28, 2026
Notes
Site-specific utility-provider review may still apply.

Fees

9 fee records

Program enrollment

AB 1332 plan review to add a plan to the City gallery

Government PDF

$1,455.43 (50% of the new-construction ADU permit fee)

Last checked
Jul 28, 2026
Notes
Current adopted 2026–27 schedule; this conflicts with the older program guide.

Modern ADU with design finishing

Vitalizebuild conditional plan-use fee

Official city source

$1,000 if constructing with Vitalizebuild

Last checked
Jul 28, 2026
Notes
Provider-submitted fee in the City gallery; it covers the stated site, architectural, and structural plan package subject to the provider condition.

Plans over 750 sq ft

Development impact fee

Official city source

No impact fee at 750 square feet or less; proportional charge above 750 square feet

Last checked
Jul 28, 2026
Notes
The project-specific amount depends on the ADU and applicable fee categories.

Detached

Utility connection or capacity charge

Official city source

Conditional; proportional charges may apply to a new detached ADU

Last checked
Jul 28, 2026
Notes
Conversions are treated differently; consult the City and utility provider for a parcel-specific determination.

Program enrollment

Older guide Phase 1 plan-preapproval fee

Government PDF

$2,831.57 in the 2025 guide; conflicts with the current 2026–27 adopted schedule of $1,455.43

Last checked
Jul 28, 2026
Notes
Do not use the older amount without City confirmation; the newer adopted fee schedule is treated as controlling.

Official Sources

27 sources

San Mateo ADU FAQ

6 answers

Does San Mateo have accepted or pre-approved ADU plans in this directory?

Yes. The current San Mateo, California page lists 17 accepted plans from 8 providers in the source-backed export.

What ADU plan sizes are listed for San Mateo?

The listed San Mateo plan records range from 340 to 1,110 sq ft. Use the individual plan cards to confirm bedrooms, bathrooms, plan documents, and provider details because some fields are not listed by every official source.

Where do the San Mateo ADU plan records come from?

They are tied to 27 official sources in this page's source set, including City of San Mateo, City of San Mateo / Community Planning Collaborative, and Community Planning Collaborative. Each plan, fee, and permit note should still be checked against the linked official source before use.

Can San Mateo County or nearby city ADU plans be used in San Mateo?

The current San Mateo records do not show accepted plans from a separate San Mateo County or nearby city program. Treat outside pre-approved plans as unavailable in San Mateo unless an official San Mateo source says they are accepted.

Do pre-approved ADU plans guarantee permits in San Mateo?

No. A source-backed accepted plan can reduce plan review work, but San Mateo can still require site-specific review, zoning checks, fees, utility coordination, and current code compliance. This page lists 18 permit requirements to help flag items to verify with the local building department.

Are San Mateo ADU permit fees and requirements listed?

This page includes 9 fee records and 18 permit requirements for San Mateo. These are source-backed summaries, not a final permit quote or approval checklist.