Davis Zoning and ADU Guide for Homeowners

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

Davis regulates accessory dwelling units in sections 40.26.450 and 40.26.460 of its zoning code, with a ministerial building-permit path and a separate non-ministerial path that needs an administrative use permit. This guide summarizes the size, height, setback, parking, rental and fee rules in the city’s ordinance, notes that the city has proposed new ADU amendments, and explains what to do if you own a home with a converted garage or an older unpermitted unit.

Davis ADUs at a glance

Governing law	Davis Municipal Code sections 40.26.450 and 40.26.460, plus state ADU law
Detached ADU size	Up to 850 sq ft (0 to 1 bedroom) or 1,000 sq ft (2 or more bedrooms)
Attached ADU size	No more than 50% of the primary dwelling’s floor area
Minimum size	150 sq ft, or the efficiency unit minimum
Height	Detached 18 ft (plus 2 ft for roof pitch); attached 25 ft or the zone limit, whichever is lower
Setbacks	4 ft side and rear for new ministerial ADUs; none for conversions of existing structures
Parking	No additional parking required; none to replace a converted garage
Rental term	Longer than 30 days

Two paths: ministerial and non-ministerial

Section 40.26.450 covers ADUs that qualify for building-permit-only approval under state law. Section 40.26.460 covers non-ministerial ADUs, which do not meet the standards of section 40.26.450 and need an administrative use permit.

Non-ministerial units can be up to 1,200 square feet and 30 feet tall, with a front setback matching the zone, 15 feet on a street side, 5 feet on an interior side and 10 feet at the rear (3 feet for interior side and rear yards next to an alley, park or greenbelt, or a district that does not principally allow single-family or two-family homes). No additional parking is required on that path either.

Rules for ministerial ADUs and JADUs

Ministerial ADUs are processed within the timelines in Government Code section 66317. They may be rented only for terms longer than 30 days.

A junior ADU needs a building permit and a recorded covenant restricting separate sale and short-term rental, and if it shares sanitation facilities with the main home, the owner of record must live in either the JADU or the main portion of the house.

Fees follow state law: ADUs under 750 square feet pay no impact fees, and larger ones are charged impact fees in proportion to the primary home’s square footage.

Pending city changes

The city’s ADU page notes that state updates since the 2021 city update may make some Chapter 40 rules differ from current state law, and a city notice dated August 5, 2026 announces proposed amendments to Chapter 40 to update the ADU ordinance. Check the city’s ADU page for the current text before you design a unit.

How to start in Davis

1. Confirm your zone and lot

Ask Community Development and Sustainability to confirm your zoning and any overlay, easement or flood issues.

2. Pick a path

Check whether your design fits the ministerial standards. If not, ask about the administrative use permit.

3. Plan check and permits

See our Davis permits guide for how plan check and inspections work.

State ADU law and Davis

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 sets ministerial review timelines, limits the standards a city can require, 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 Davis 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?

Garage conversions and older unpermitted units

A garage conversion replaces the garage with living space, and the Davis ordinance does not require replacement parking. Both conversions and backyard units are common sources of unpermitted space in older Davis 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

Larger new units can 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 Davis

1. Check which structures on the property are permitted ADUs, conversions or unpermitted.
2. Collect permits, plans and any city notices.
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 Davis page and the Yolo County hub.

Frequently asked questions

What is the maximum detached ADU size in Davis?

850 square feet for a studio or one bedroom, or 1,000 square feet for two or more bedrooms, under section 40.26.450.

Does Davis require parking for an ADU?

No. The ordinance requires no additional parking for ministerial or non-ministerial ADUs, and none to replace a converted garage.

What setbacks apply to a new ministerial ADU?

Four feet from side and rear lot lines, with no new setback for conversions or same-footprint replacements.

Can I rent my Davis ADU short term?

No. Ministerial ADUs and JADUs may be rented only for terms longer than 30 days.

Does Davis charge impact fees for an ADU?

ADUs under 750 square feet pay none; larger ones pay fees proportional to the main home’s size.

Can I sell my Davis house with an unpermitted ADU or garage conversion?

Yes. You can disclose it and sell as-is, including to a cash buyer. Our statewide guide explains the disclosure rules.

More guides

• We Buy Houses in Davis
• We Buy Houses in Yolo County
• Yolo County Property Tax Guide
• Davis Building Permits Guide
• Davis Code Enforcement Guide
• All California Guides

Sources

• Davis Municipal Code Article 40.26: Special Uses (ADUs)
• City of Davis: Accessory Dwelling Units and Guest Houses
• 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.