ADU Constructionin Moreno Valley, CA
ADU construction in Moreno Valley follows state ADU law plus the City's own code. A single-family lot may have one ADU and one junior ADU, the City approves a complete application within 60 days, and it offers seven pre-approved detached plans from 306 to 988 square feet. Its size and height numbers conflict between documents, so confirm yours.
Moreno Valley has the lots for second units. Of the 59,400 homes in the Census Bureau's 2024 one-year estimate, 43,916, or 73.9 percent, are single-family detached, and 39.0 percent of occupied homes are rented, which is the market a second unit serves. The median owner-occupied home is worth $581,500, plus or minus $10,663. Most of the stock came in the 1980s boom, 39.7 percent of it, on land that was three rural communities until the City incorporated on December 3, 1984, so many lots carry a house 35 to 45 years old with room behind it. One-year estimates for a city this size are loose, so read every share as approximate.
ADUs are the biggest topic in this city, and the City's own documents do not always agree. This page covers size and height, the pre-approved plans, garage conversions, fire zones, utilities, JADUs and rentals, and the clocks and fees. The City runs a dedicated site, ADUforYOU, and permits go through Building and Safety. We read the municipal code on GoCodebook, a labeled third-party mirror, because the official eCode360 host refused our tools, so confirm every number with the permit counter. Price ranges and phases are on our ADU construction page.
City of Moreno Valley rules that apply to ADU construction
Where adu construction permits come from in Moreno Valley: City of Moreno Valley Community Development Department, Building and Safety Division.
- Moreno Valley's ADU site (ADUforYOU) says ADUs come as converted space, attached, detached and junior ADUs, and offers seven City-owned pre-approved detached plans (Plan 1 studio 415 sq ft, Plan 2 studio 306, Plan 3 one-bedroom 730, Plan 4 one-bedroom 586, Plan 5 two-bedroom 910, Plan 6 two-bedroom 779, Plan 7 three-bedroom 988). A designer must still customize the template sheets and add a scaled site plan and Title 24 sheets.
- Pre-approved ADU plans can be used only on residential lots with an existing single-family home or duplex that are not in a geo-hazard zone, landslide zone, flood zone or Wildland-Urban Interface area, per the ADU home page.
- The City's detached and attached ADU pages describe self-sufficient units with a kitchen, living area, bathroom and bedrooms and a maximum size of 1,000 square feet, and say the City creates a separate address while a separate electric meter is not required but recommended. Permit staff are at permitcounter@moval.org or 951.413.3350, option 5.
- Municipal code Section 9.09.130 (third-party mirror; its history line ends with Ordinance 1040 dated 4/7/2026) lets a single-family lot have one ADU plus one JADU under local standards, and up to three units (one conversion, one JADU and one detached ADU) under state by-right standards; multifamily lots may have up to eight detached ADUs not exceeding the number of existing units. Its local standards table (E-1) sets detached ADUs at 1,000 square feet and 20 feet high with 4 foot side and rear setbacks, attached ADUs at 50 percent of the existing home (a 1,000 square foot ADU is always permitted), and 10 foot separation from the home in front or behind (5 feet at the side).
- The ADU code's by-right table (E-2) allows one new detached ADU of up to 800 square feet and 20 feet high with 4 foot side and rear setbacks, and conversions of existing space with no size limit; the table notes say the standards do not apply to an ADU of 800 square feet or less with 4 foot side and rear setbacks. The City's August 2023 handout shows older numbers (16 foot height baseline, 850 and 1,000 square foot caps), so the newer code text is what this file cites for size and height.
- Moreno Valley approves or denies a complete ADU or JADU application within 60 days (deemed approved if the City misses it), determines completeness within 15 business days, and must send written comments listing defects if it denies; if the lot is on a septic system the owner must first verify with Riverside County Environmental Health that it can support the ADU (Section 9.09.130.C).
- ADU parking in Moreno Valley is one space per ADU or per bedroom, whichever is less, and may be tandem on a driveway; no replacement parking is required when a garage, carport or uncovered space is removed, and no extra parking is required within one-half mile of a fixed-route transit stop, within a block of a car share, in a listed historic district, or when the ADU is part of an existing dwelling or accessory structure (Section 9.09.130.F).
- The City's JADU page says a Junior ADU is a conversion of 500 square feet or less within an existing single-family home or garage, with a separate entrance and an efficiency kitchen, no new address and no separate electrical meter; the owner must live on site and sign a covenant agreement with the City. The code's JADU rules (Section 9.09.130.G) add a recorded deed restriction and limit the owner-occupancy covenant to JADUs that share a bathroom.
How big and how tall can an ADU be in Moreno Valley? The 2023 handout and the code disagree
The newest text we found is the code. Section 9.09.130 on the mirror carries a history line that ends with Ordinance 1040, dated April 7, 2026. Its local standards table sets a detached ADU at 1,000 square feet and 20 feet high with 4 foot side and rear setbacks, and an attached ADU at up to 50 percent of the existing home, with 1,000 square feet always permitted. The by-right table allows one new detached unit of up to 800 square feet and 20 feet, and conversions of existing space with no size limit. The City's web pages also give 1,000 square feet.
The City's August 3, 2023 handout says something different: 850 square feet for an efficiency or one bedroom, 1,000 for two or more bedrooms and a 16 foot height baseline. We state that as a conflict, not a ruling. State law sets floors under any local cap: a city may not cap an ADU below 850 square feet, or 1,000 with more than one bedroom, and must allow 800 with 4 foot setbacks. Ask the counter which version governs your file.
There is a second layer. On December 9, 2024, the state housing department found the City's Ordinance 999 out of compliance with state ADU law on several points and asked for a written response by January 9, 2026, in a letter posted on the department's site. Later amendments exist, Ordinances 1013, 1028, 1035 and 1040, and we did not find whether the department accepted them.
Does Moreno Valley have pre-approved ADU plans, and who cannot use them?
Yes, seven of them, all detached and owned by the City. Plan 1 is a 415 square foot studio, Plan 2 a 306 square foot studio, Plan 3 a 730 square foot one-bedroom, Plan 4 a 586 square foot one-bedroom, Plan 5 a 910 square foot two-bedroom, Plan 6 a 779 square foot two-bedroom and Plan 7 a 988 square foot three-bedroom. A designer still has to customize the template sheets and add a scaled site plan and the Title 24 energy sheets.
The plans have an exclusion list. According to the City's ADU home page they can be used only on residential lots with an existing single-family home or duplex that are not in a geo-hazard zone, landslide zone, flood zone or wildland-urban interface area. That removes the foothill neighborhoods the Safety Element lists as Very High fire areas, such as Serrano Heights, Moonlight Rim and Bernasconi Hills, and the streets it says flood about every two years. Check your parcel before falling for a floor plan.
Size also drives fees. Plans 2, 1, 4 and 3, at 306, 415, 586 and 730 square feet, fall under the 750 square foot line below which the code bars impact fees, while Plans 6, 5 and 7, at 779, 910 and 988, fall above it.
Can you convert a garage into an ADU in Moreno Valley? Parking, the slab and the landscaped strip
Parking is the easy part. The code requires one space per ADU or per bedroom, whichever is less, and allows it to be tandem on a driveway. No replacement parking is required when a garage, carport or uncovered space is removed, and none is required within a half mile of a fixed-route transit stop, within a block of a car share, in a listed historic district or when the ADU is inside an existing dwelling or accessory structure.
The slab is where garages surprise people. The City's handout notes that most garages step down and slope, and it asks for a 6-mil vapor barrier under a topcoat slab poured over the existing concrete, which covers the barrier and levels the floor. A new foundation needs a pad compaction report first. The code adds a landscaped strip at least 2 feet deep next to the former garage door and an unobstructed path from the street to one ADU entrance, and says outside stairs serving ADUs should not face a public street.
State law protects a conversion with a junior ADU beside it, with up to 150 square feet added only for entry and exit. Our garage conversion permit steps show the Los Angeles sequence, where the paperwork differs.
Can you build an ADU in a Moreno Valley fire zone, and do you need sprinklers?
Often, with extra steps. The City adopted moderate, high and very high zones from the State Fire Marshal's 2025 map under Ordinance 1024, and the Safety Element names Very High areas at Sunnymead Ranch, Hidden Springs, the Box Springs foothills and Bernasconi Hills. The ADU guidebook says plans in a High or Very High zone must meet Title 7A construction and Title 14 fire setbacks and include a Fuel Modification Plan. The 2025 wildland-urban interface chapter adds a non-combustible Zone 0 for the first 5 feet and 100 feet of cleared combustibles before framing starts. We could not read parcel zones, so use the State's viewer.
Sprinklers are where the City's two documents split. The August 2023 handout says none are required if the main house has none, the detached unit is 1,200 square feet or less and it sits on the same lot, and it asks for a 24 foot fire access road within 150 feet of every exterior side. The guidebook says the ADU needs sprinklers if the home has them, and a water will-serve letter showing over 1,000 gallons a minute at 20 psi lets you skip the plan. State law says an ADU cannot trigger sprinklers in the main house. Ask Fire Prevention at 951.413.3370.
Which water, sewer and power providers serve a Moreno Valley ADU, and what comes first?
It depends on the address. The City's ADU FAQ names Eastern Municipal Water District for water and sewer, Box Springs Mutual Water Company for water only, Edgemont Community Services District for sewer only, Riverside County Environmental Health for septic, Southern California Edison or Moreno Valley Utility for electric and SoCal Gas, plus Moreno Valley Unified or Val Verde Unified for school fees. On septic, you must first verify with the County that the system can support the ADU.
The guidebook sets an order. A new address comes first for every ADU but a junior one, requested through SimpliCITY with a dimensioned plot plan. Then a water will-serve letter less than 12 months old, a site plan, a title sheet and a soils report, and a pad certification and compaction report before the building permit. A grading plan goes to Land Development, at 951.413.3120, if you move 50 cubic feet of soil or raise the foundation a foot, though the grading code's exemption reads 50 cubic yards, so ask which is meant.
A separate electric meter is recommended but not required. A second water or electric meter that crosses the right-of-way needs an encroachment permit, and a newly built detached ADU needs solar under the Energy Code.
JADUs, rentals and HOAs: do you have to live on the property in Moreno Valley?
For a junior ADU, the City says yes and the code says maybe. A junior ADU is a conversion of 500 square feet or less inside an existing house or garage, with a separate entrance and an efficiency kitchen, no new address and no separate electric meter. The City's page says the owner must live on site and sign a covenant, while Section 9.09.130.G limits that covenant to units sharing a bathroom and adds a recorded deed restriction. State law matches the code: owner occupancy only if sanitation is shared.
ADU rentals must run longer than 30 days. The City's FAQ says short-term rentals are not allowed and that the owner of a rented ADU needs a business license. A single-family lot may have one ADU and one junior ADU under local standards, and up to three units under state standards, one conversion, one junior unit and one detached ADU. Multifamily lots may have up to eight detached ADUs, not above the number of existing units.
Associations cannot block you. Section 9.09.130.A says a local homeowners association cannot prohibit an ADU or junior ADU. Sunnymead Ranch has a planned community association, and which neighborhoods are association-governed was not on our list, so read your CC&Rs.
How long does an ADU permit take in Moreno Valley, and which fees apply?
The City has 15 business days to call a complete application complete and 60 days to approve or deny it, and silence past 60 days counts as approval. A denial must list the defects in writing. Filing is online only through SimpliCITY, and hard-copy ADU plans are not accepted. We found no figure for how long a custom ADU takes to build, so we promise none.
On fees, the code bars impact fees on junior ADUs and on ADUs under 750 square feet. At 750 or more, the City's handout adds a Development Impact Fee and a pass-through multi-species habitat fee, and every ADU must annex into the Parks Maintenance District or fund an endowment through Special Districts, at 951.413.3470. School fees vary by district. We read no dollar amounts from the Fee Schedule.
An old unpermitted unit has a path. A qualifying unit built before January 1, 2020 cannot be denied a permit for building standard violations, impact and connection fees are waived, and enforcement is delayed five years if the issue is not a health and safety one. As MDG Builders, CSLB #1040337, we draw the unit and manage the sequence while licensed foundation, framing, plumbing and electrical firms build it. Our ADU versus JADU guide compares the two unit types.
ADU photos from Moreno Valley and nearby homes
ADU scenes tied to Moreno Valley and the Inland Empire communities around it, from garage conversions and slabs to finished cottages. Tap a photo to enlarge it.
What adu construction costs around Moreno Valley
The ADU construction page puts a garage conversion to a studio or one bedroom at about $100,000 to $200,000, and a new detached unit of 400 to 800 square feet at about $200,000 to $400,000. Three outside sources stand behind them. Berkeley researchers surveyed owners who built or applied for an ADU in 2018 and 2019 and reported a Los Angeles County median of $100,000. The Terner Center estimated $148,000 for Los Angeles in 2020. And Remodeling magazine's 2025 Cost vs. Value study lists $178,536 for a Los Angeles ADU, of which 39.9 percent comes back at resale. None is a Moreno Valley quote, and Riverside County costs may differ. A typical owner-occupied home is valued at $581,500 in the 2024 figures, with a margin of $10,663. A written proposal would list permit, plan check, utility connection, school and special district charges on separate lines. How those ranges were assembled is laid out in the ADU cost guide, and the room addition versus ADU guide weighs a separate unit against more rooms in the house. For other cities see ADU construction in Pomona, Claremont and Los Angeles. A bath inside the unit is on our Moreno Valley bathroom page, a larger attached project on the Moreno Valley room addition page, windows on the Moreno Valley window page, and the Moreno Valley area page lists every trade we cover in the city.
| What it covers | Typical range |
|---|---|
| Garage conversion to a studio or one bedroom | $100,000 to $200,000 |
| New detached ADU, 400 to 800 sq ft | $200,000 to $400,000 |
| UC Berkeley survey, Los Angeles County median, 2018 and 2019 projects | $100,000 overall. $90,000 garage. $180,000 detached. |
| Terner Center and Berkeley CCI, 2020 | $148,000 Los Angeles estimate. $167,000 statewide average. |
| Remodeling Cost vs. Value 2025, Los Angeles | $178,536 job cost |
| Electrical and plumbing, Angi Los Angeles, January 2026 | Electrical $2,600 to $7,800. plumbing $3,900 to $10,400. |
| City permit and plan check fees | Not priced here |
Other work we manage in Moreno Valley
Moreno Valley ADU questions, answered
How do I build an ADU in Moreno Valley?
Start with state ADU law and the City's ADUforYOU site, choose a custom design or one of seven pre-approved plans, then apply online through SimpliCITY. A new address and a water will-serve letter come early, and every ADU needs a building permit. Because City documents conflict on size, confirm your numbers with the permit counter.
How big can an ADU be in Moreno Valley?
The code text we read allows a detached ADU of up to 1,000 square feet and 20 feet high, with 800 square feet by right. The City's 2023 handout shows 850 or 1,000 square feet and a 16 foot height, an older version. State law sets floors under any local cap, so confirm which numbers apply to your lot.
How much does it cost to build an ADU in California?
Expect roughly $100,000 to $200,000 for a garage conversion and $200,000 to $400,000 for a new detached unit of 400 to 800 square feet, based on Los Angeles surveys and one 2025 job cost. None is a Moreno Valley bid, so a written proposal after a site visit sets the figure.
Do I need to provide parking for my ADU?
Usually one space per ADU or per bedroom, whichever is less, and it may be tandem on a driveway. No replacement parking is needed when a garage or carport is converted, and none within a half mile of a fixed-route transit stop or when the ADU is inside the existing home. Ask the counter about your lot.
What is the difference between an ADU and a JADU?
An ADU is a complete, independent unit with its own kitchen and bathroom, while a junior ADU is up to 500 square feet inside an existing house or garage with an efficiency kitchen. A single-family lot may have one of each under the City's local standards. A junior unit needs a recorded deed restriction.
Do I have to live on the property to build or rent an ADU?
Not for an ADU, because state law bars owner-occupancy rules for them, but rentals must run longer than 30 days. For a junior ADU the City's page says the owner must live on site, while the code limits that rule to units that share a bathroom. Ask the counter which applies to you.
How long does it take to get an ADU permit?
The City has 15 business days to call an application complete and 60 days after that to approve or deny it, and a missed deadline means approval. Normal plan review is 12 business days once every document is in. We found no sourced figure for the build time, so we do not promise one.
Can I convert my garage into an ADU in Moreno Valley?
Yes. State law protects converting an existing garage, with a junior ADU allowed beside it, and no replacement parking is required. The City's handout asks for a 6-mil vapor barrier and a topcoat slab over the old concrete, and the code adds a landscaped strip at least 2 feet deep beside the former garage door.
Does Moreno Valley have pre-approved ADU plans I can use?
Yes. The City offers seven detached plans, from a 306 square foot studio to a 988 square foot three-bedroom. A designer must still customize them and add a site plan and energy sheets. They cannot be used on lots in a geo-hazard, landslide, flood or wildland-urban interface area, so check the parcel first.
Can my HOA stop me from building an ADU?
No, not by prohibition. Section 9.09.130.A of the municipal code says a local homeowners association cannot prohibit the construction of an ADU or a junior ADU, and state law agrees. An association may still apply reasonable rules on other matters, so read your CC&Rs and tell the board early.
Tell us about your Moreno Valley ADU plans
Tell us the neighborhood, whether you are weighing the garage or the back yard, whether one of the City's seven plans appeals and whether the lot is flat, on a slope or near open land, and we will plan the first visit around that.