Richmond, CA Zoning and ADU Guide for Homeowners

Last updated November 13, 2026. Reviewed by the Cash Home Buyers CA team.

Richmond’s Planning Commission recommended approval of ADU and junior ADU zoning amendments to align the city’s code with state law, and the city offers pre-approved ADU plans. This guide explains what the city’s recent ADU ordinance update covers, the state review timelines it must follow, and how an ADU or unpermitted conversion affects a sale.

The city’s ADU page did not load for us, so we do not state size, height or setback numbers. Check the current ordinance before you design.

Richmond ADU rules at a glance

Ordinance update	Zoning Text Amendments to Richmond Municipal Code sections 15.04.104.020, 15.04.201.030, 15.04.201.050 and 15.04.610.020
Planning Commission	April 2, 2026: Resolution No. 26-07 recommending approval, 5-0
State law driving it	California Government Code sections 66310 through 66342, plus changes the Legislature enacted in October 2025 that took effect in January 2026
Review timeline	60 days for the overall application; 30 days to approve or deny pre-approved plans
Pre-approved plans	The city lists an ADU Pre-approved Plans page
Size, height, setbacks	Not stated in the city text we could read

What the 2026 update changes

According to the Planning Commission record, staff proposed text amendments to align Richmond’s code with state law.

The changes include renumbering and relocating provisions of the Government Code, clarifying the law on uncovered parking, creating by-right combinations that can increase the number of ADUs allowed on a lot, updating the definitions of attached and detached ADUs and junior ADUs, narrowing the livable-space definition for storage rooms and closets converted into ADUs, and updating the application process.

The Commission voted 5-0 to recommend approval. A recommendation goes on to the City Council, and we did not confirm its final adoption, so check the municipal code for the current text.

Pre-approved plans

The city’s department pages list ADU Preapproved Plans, and the Design Review Board discussed a citywide pre-approved plan program in 2024. State changes shortened the program’s timeline: the city has 30 days to offer an approval or a denial for pre-approved plans. If you are weighing an ADU, ask Planning whether a pre-approved design fits your lot, because it can reduce design work.

State ADU law and Richmond

California’s ADU statute, Government Code section 66314 and following, sets a floor that every city must follow, and local ordinances fill in the details.

The state requires ministerial review within 60 days of a complete application, bars a city from requiring more than a limited set of standards, and generally allows an ADU or conversion inside existing space without added setbacks.

The California Department of Housing and Community Development (HCD) publishes a handbook and keeps a list of the state requirements. Because state law changes often, treat the city’s current ordinance and handout as the final word on size, height, parking and fees for your lot.

ADUs, garage conversions and selling a Richmond house

Many older homes have a converted garage or a backyard unit built without permits. Buyers and lenders ask about them, and California sellers generally disclose known unpermitted work. Our guide to selling as-is with unpermitted work explains the rules, and our Prop 13 guide explains how new construction can affect property tax. Before you list:

• Check city records for permits on any ADU, conversion or addition.
• Ask Planning whether the structure could qualify under current rules.
• Estimate plans, fees and corrections needed to legalize it.
• Compare that with selling as-is and letting a cash buyer take on the legalization.

Questions to ask Planning before you design

• Does my lot and zone allow an ADU, a junior ADU, or both?
• Is a pre-approved or pre-reviewed ADU plan available?
• What are the current impact, utility and school fees for the size I am considering?
• Can my existing garage or accessory structure be converted without changing its footprint?
• Are there fire, slope, easement or utility constraints on my lot?

Junior ADUs and garage conversions in more detail

State law treats a junior ADU as a unit of up to 500 square feet created inside the walls of an existing or proposed single-family home, with an efficiency kitchen and a recorded restriction that keeps it from being sold apart from the house.

A garage conversion is a different path: the unit replaces the garage, and state law generally does not require the city to demand replacement parking. Both are common sources of unpermitted space in older Richmond neighborhoods, which is why buyers’ agents and appraisers ask for the permit record.

If a conversion was done without a permit, the usual fix is to submit as-built drawings, pay the fees and pass inspection, which can take months and cost real money.

Fees, utilities and property tax

State law limits the impact fees a city can charge on smaller ADUs and on conversions of existing space, and it limits when a separate utility connection can be required.

Larger new units can still carry impact fees, school fees and water or sewer connection charges, so ask for an itemized estimate before you commit to plans. New construction is generally reassessed for property tax under Prop 13, which means an ADU can raise the bill for the whole property. Our Prop 13 guide explains how reassessment works.

Why ADUs matter for resale

A permitted ADU can add rental income and appeal for some buyers, but an unpermitted one can complicate financing and appraisal. Lenders typically want permitted living area, and an appraiser may not count unpermitted space.

Because an ADU generally cannot be sold separately from the main home, its value comes through the sale of the whole property.

If you inherited a house with an old backyard unit, or bought one with a converted garage, check what the city has on file before you decide how to sell. Our probate home sale guide covers inherited property.

How to sell a house in Richmond

1. Check city records for permits on any ADU, conversion or addition.
2. Ask Planning whether the structure could qualify under current rules.
3. Request a no-obligation cash offer for the house as it stands.
4. Choose your closing date.
5. Close with no legalization, repairs or showings required.

See also our Richmond page, the Richmond as-is sale page and the Contra Costa County hub.

Frequently asked questions

What did Richmond’s Planning Commission approve about ADUs?

On April 2, 2026 it voted 5-0 on Resolution No. 26-07 recommending approval of zoning text amendments for ADUs and JADUs.

How long does the city have to review an ADU?

The Commission record cites 60 days for the overall application process and 30 days to approve or deny pre-approved plans.

Does Richmond have pre-approved ADU plans?

The city lists an ADU Pre-approved Plans page under its department pages.

What are Richmond’s ADU size and setback limits?

The pages we could read did not show them. Check the current municipal code or ask Planning.

Can I sell a house with an unpermitted ADU?

Yes. You can disclose it and sell as-is, including to a cash buyer. Lenders and appraisers may not count unpermitted space.

Does an ADU change my property tax?

New construction is generally reassessed under Prop 13. Our Prop 13 guide explains how.

More guides

• We Buy Houses in Richmond
• We Buy Houses in Contra Costa County
• Contra Costa County Property Tax Guide
• Richmond Building Permits Guide
• Richmond Code Enforcement Guide
• Sell Your Richmond House As-Is
• Richmond Cash Offer Process
• All California Guides

Sources

• City of Richmond: Planning Commission record on ADU ordinance amendments (April 2, 2026)
• City of Richmond: Design Review Board record on pre-approved ADU plans (2024)
• City of Richmond: City Departments (ADU pages)
• California HCD: Accessory Dwelling Units

This guide is general information from public sources, not legal advice. Confirm current rules, fees and hours with the city.