Desert Hot Springs Zoning and ADU Guide for Homeowners

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

Desert Hot Springs allows accessory dwelling units under Section 17.08.090 of its municipal code, with detached units up to 1,200 square feet or half the primary dwelling (whichever is less), and the city offers eight pre-approved detached ADU plans designed with YNG Architects. This guide summarizes the city’s published ADU and junior ADU standards and its septic restriction.

State ADU law changes often and the city amends its code to follow it, so confirm every number with Planning before you design.

Desert Hot Springs ADU rules at a glance

Pre-approved plans	Eight pre-approved detached ADU plans, offered with YNG Architects
Attached ADU size	Up to 50 percent of the primary dwelling or 850 square feet (1,000 square feet if it has more than one bedroom and the primary dwelling is under 1,600 square feet)
Detached ADU size	Up to 50 percent of the primary dwelling or 1,200 square feet, whichever is less; an 800 square foot unit with 4-foot side and rear setbacks is protected
Minimum size	150 square feet in the ADU section; the use table lists 300 square feet, so ask Planning which applies
JADU size	150 to 500 square feet, contained entirely within a single-family residence
Height	16 feet for a detached new unit, 18 feet near major transit or on a multifamily lot, up to 2 more feet to match the main roof pitch, and 25 feet or the main home’s limit for an attached unit
Setbacks	None for conversions of existing space; no more than 4 feet from side and rear lines for new units
Parking	No more than one space per ADU or bedroom, with many exceptions, including near transit and for conversions
Review time	60 days from a completed application when a single-family home already exists
Septic	City page: not permitted on septic lots under 1 acre; code: county environmental health approval and a recent percolation test where septic is used
Rental	Rental terms must exceed 30 days; ADUs are not eligible for a short-term vacation rental permit

Where the rules come from

California statutes set the statewide floor, and HCD publishes a handbook explaining it. Desert Hot Springs implements those rules in Chapter 17.08 of its municipal code, and the city has amended its ADU and JADU sections more than once to match state law. The city’s own documents have referred to the ADU section by different numbers over time, so cite the current section when you speak with Planning.

The pre-approved plan program

The city worked with YNG Architects to offer property owners a selection of eight pre-approved ADU plans, intended to promote new detached ADUs within city limits.

A pre-approved plan can shorten design time because the layout has already been drawn, but you still need to submit your own site plan and meet the code’s development standards for your lot.

The city’s page also flags the septic restriction in its first line, which is worth reading before you pick a plan.

Step by step: building an ADU

1. Confirm your lot qualifies

Check zoning, sewer or septic service and any easements. If your property uses a septic system, the city’s page says ADUs are not permitted on septic lots smaller than one acre.

The code also requires approval from the Riverside County Department of Environmental Health and the Regional Water Quality Control Board where a private sewage disposal system is used or proposed, plus a percolation test completed within the last five years or recertified within the last ten.

2. Choose a plan and design the unit

Pick one of the pre-approved plans or commission your own design. Match the unit to the size caps above, and confirm height and setbacks for a detached unit.

3. Submit a building permit application

The city acts on a complete ADU building permit application within 60 days when an existing single-family dwelling is on the lot. Missing items are the most common cause of delay.

4. Pay fees

The code says you pay applicable fees, but no impact fee may be charged for an ADU under 750 square feet, and fees for larger units must be proportional to the primary dwelling’s square footage. Ask the city for a written estimate.

5. Inspections and certificate of occupancy

Request inspections through the city’s portal or at (760) 329-6411, extension 244, as described in our Desert Hot Springs building permits guide.

Junior ADUs

A junior ADU must be no more than 500 square feet and contained entirely within a single-family residence. The code requires the owner to live in either the main home or the JADU, a recorded deed restriction before the certificate of occupancy, and no additional parking beyond what the home already needs. It also says a JADU is not a separate dwelling for water, sewer or power connection purposes.

Rental and sale rules

An ADU may be rented separately from the primary residence, for terms longer than 30 days, but may not be sold or conveyed separately except as state law allows. ADUs are not eligible for a short-term vacation rental permit. Tell any buyer about the deed restriction on a JADU and the rental limits on an ADU.

Parking and garage conversions

The code limits parking to no more than one space per ADU or per bedroom, whichever is less, and allows tandem parking on a driveway. It lists situations where no extra parking is required, including within half a mile of public transit and where the unit is part of an existing structure, and it says spaces lost to a demolished garage or carport need not be replaced.

Should you legalize an existing unit first?

If you already have a garage conversion or backyard unit without permits, ask the Building and Safety Division what it would require, such as plans, inspection of concealed work and corrections. Legalizing can make the property easier to finance, insure and sell, but cost and time vary, so get a written scope first.

Property tax on new construction

A newly built ADU is generally reassessed as new construction, so the county assessor may increase the property’s taxable value. See our Riverside County property tax guide for how reassessment works.

ADUs, garage conversions and selling a Desert Hot Springs house

Second units and garage conversions are common, and so are the questions they raise at sale. Lenders typically want permitted living area, and an appraiser may not count unpermitted space. Our statewide guide covers seller disclosure of unpermitted work, and the Prop 13 guide covers reassessment on new construction. If your Desert Hot Springs property has a second unit:

• Look up permits and final inspections for the unit.
• Ask the city whether it would approve the structure today.
• Price the plans, corrections and fees to legalize it.
• Weigh that against an as-is sale to a buyer who accepts the unit as it stands.

How to sell a house in Desert Hot Springs

1. Check which structures, additions and conversions on the property have city permits.
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 repairs, permit cleanup or showings required.

Our local pages cover related situations in Desert Hot Springs, including selling as-is, selling an inherited house and selling during a divorce. See also our Desert Hot Springs page and the Riverside County hub.

Frequently asked questions

Does Desert Hot Springs offer pre-approved ADU plans?

Yes. The city offers eight pre-approved detached ADU plans in collaboration with YNG Architects.

How big can a Desert Hot Springs ADU be?

Under Section 17.08.090, a detached ADU may be up to 50 percent of the primary dwelling or 1,200 square feet, whichever is less; an attached ADU up to 50 percent or 850 square feet (1,000 for a unit with more than one bedroom where the main home is under 1,600 square feet); and a JADU up to 500 square feet.

Can I build an ADU if my lot is on septic?

The city’s ADU page says ADUs are not permitted on septic lots smaller than one acre. The code also requires county environmental health approval where a private sewage system is used. Confirm your lot with the city.

How long does the city take to review an ADU application?

The code says the city acts on a completed building permit application within 60 days when a single-family home already exists on the lot.

Can I rent my Desert Hot Springs ADU short-term?

No. The code requires rental terms longer than 30 days and says an ADU is not eligible for a short-term vacation rental permit.

Can I sell my Desert Hot Springs 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 Desert Hot Springs
• We Buy Houses in Riverside County
• Riverside County Property Tax Guide
• Desert Hot Springs Building Permits Guide
• Desert Hot Springs Code Enforcement Guide
• Palm Desert Building Permits Guide
• Coachella Building Permits Guide
• All California Guides

Sources

• City of Desert Hot Springs: Accessory Dwelling Units (ADUs)
• Desert Hot Springs Municipal Code, Chapter 17.08 (Residential Districts)
• 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.