ADU Rules in Riverside County, California
We track 9 cities in Riverside County. Each city writes its own ADU ordinance on top of California law, so size limits, fees, and design rules differ from one city to the next. Among the cities we track, Hemet has the lowest starting permit fees ($4,000 – $8,000).
Cities
9
Max Detached Size
1,000–1,500 sq ft
Build Costs From
$110,000
Pre-approved Plans
5 of 9 cities
Riverside County Cities Compared
| City | Max detached | Height | Permit fees | Build cost |
|---|---|---|---|---|
| Riverside | 1,200 sq ft | Up to 30 ft | $5,000 – $11,000 | $110,000 – $240,000 |
| Moreno Valley | 1,200 sq ft | 16 ft | $4,500 – $10,000 | $110,000 – $230,000 |
| Corona | 1,200 sq ft | Per zone, but at least 16 ft must be allowed (state law: 18 ft near major transit | $6,000 – $13,000 | $145,000 – $300,000 |
| Murrieta | 1,200 sq ft | 16 ft | $6,000 – $12,000 | $145,000 – $295,000 |
| Temecula | 1,200 sq ft | 16 ft (detached) | $6,500 – $13,000 | $150,000 – $305,000 |
| Jurupa Valley | 1,000 sq ft | 16 ft (detached) | $5,500 – $11,000 | $130,000 – $270,000 |
| Menifee | 1,500 sq ft | 16 ft detached | $5,500 – $11,000 | $135,000 – $275,000 |
| Hemet | 1,200 sq ft | 16 ft | $4,000 – $8,000 | $110,000 – $225,000 |
| Palm Springs | 1,000 sq ft | 16 ft | $6,000 – $12,000 | $155,000 – $315,000 |
Riverside ADU rules
Riverside allows detached ADUs up to 1,200 sq ft and heights up to 30 ft, but any ADU taller than 16 ft must meet the side and rear setbacks of the main house. The Dwell Riverside program offers free permit-ready plans from 746 to 1,200 sq ft in Craftsman, Ranch and Spanish styles. ADUs on historic properties follow separate design standards.
Moreno Valley ADU rules
Moreno Valley's ADU for You program offers seven city-owned pre-approved detached ADU plans, studio to three bedrooms, free of charge in Craftsman, Spanish, Ranch or Tuscan styles. The free plans cannot be used on lots in geo-hazard, landslide, flood or Wildland-Urban Interface areas. Many newer tracts are HOA-governed, so check CC&Rs for design rules.
Corona ADU rules
Corona reviews ADUs ministerially within 60 days and publishes an ADU Guide Sheet (updated October 2024) on its Planning forms page. A pre-approved ADU plan program was still being set up, with designers invited to submit plans. Hillside and gated neighborhoods often have HOAs, which can set design rules but cannot ban ADUs.
Murrieta ADU rules
Murrieta keeps a pre-approved ADU plan library (Information Bulletin IB-113): plans are submitted by private architects and designers, and homeowners contact the plan owner for permission to use them. Building and Safety bulletin IB-108 sets 4 ft side and rear setbacks and lets converted legal garages keep existing setbacks. Many neighborhoods are HOA-governed planned developments with their own design rules.
Temecula ADU rules
Temecula's ADU rules are in Municipal Code Chapter 17.23 and require a 6 ft separation between a detached ADU and the main house. The city offers free Permit Ready ADU (PRADU) plans, and a detached ADU must either use one of them or match the main home's materials and colors. Most master-planned neighborhoods have HOAs, and Wine Country specific plan areas have their own overlay rules.
Jurupa Valley ADU rules
Jurupa Valley caps attached and detached ADUs at 850 sq ft for one bedroom and 1,000 sq ft for two or more, and requires them to match the main home's design, colors and materials. The City Council updated the ADU ordinance in October 2025 (Ordinance 2025-22) to reflect new state laws. Large former agricultural lots leave room for detached units, and sewer fees are charged separately by the water district.
Menifee ADU rules
Menifee's own FAQ allows ADUs up to 1,500 sq ft of living space, larger than the 1,200 sq ft cap many cities use. The city offers free Permit Ready ADU plans in eight floor plans from a 305 sq ft studio to a 1,198 sq ft three-bedroom, which cuts design cost and plan review time. Many lots are in newer planned communities where the lot size leaves room for a detached unit.
Hemet ADU rules
Hemet's Building & Safety Division publishes an ADU Plan Check Guide covering addressing and submittal details, while Planning answers questions on setbacks, height and unit size. Large inland lots, including RA (Residential Agriculture) parcels, leave plenty of room for detached units. Permit fees are low compared with coastal Southern California.
Palm Springs ADU rules
Palm Springs has no pre-approved ADU plan program, so homeowners need a custom or vendor design. Short-term vacation rental of an ADU needs a separate city permit subject to caps, while long-term rentals of 30 days or more are not restricted. Historic and architectural overlay areas with midcentury homes may require design review.
Rules that apply in every California city are summarized in our California ADU law guide. See all California cities or compare every city side by side.