ADU Builder in Menifee, CA: Permit-Ready Plans, Fees and Costs

How big can a detached ADU be in Menifee?

Menifee's June 2026 ADU Guidebook lists the city development standards for accessory dwelling units: one ADU and one junior ADU per single-family lot, a detached maximum of 1,200 square feet, and an attached maximum of 1,200 square feet or 50% of the primary residence floor area, whichever is less. Side and rear setbacks are the same as the existing primary dwelling or 4 feet, whichever is less, and a 16 foot height is allowed by right. Lot coverage follows the existing zoning, and 800 square feet of ADU is allowed by right. State law sets the floor under those rules: no local rule can block an ADU with at least 800 square feet of interior livable space and four-foot side and rear yard setbacks (Gov. Code Section 66321), and a detached ADU cannot exceed 1,200 square feet of floor area (Gov. Code Section 66314).

How long does the City of Menifee take to review an ADU permit?

The city's Permit Ready ADU checklist puts the first submittal review at about 10 business days and each later review at about 10 business days as well, with plans routed to Building, Planning, Engineering and Fire. All City applications are processed digitally through the Menifee Permit Portal. State law sets the outer clock: a permitting agency must tell you in writing whether an application is complete within 15 business days, and must approve or deny a complete application within 60 days, with an application the city has not acted on in 60 days deemed approved (Gov. Code Section 66317). A separate grading plan and permit from Engineering can be required before the building permit is issued, and that applies at 50 cubic yards of earthwork.

What does the City of Menifee charge for an ADU permit?

The City's Building and Safety permit fee schedule effective July 1, 2026 lists the Accessory or Additional Dwelling Unit permit at $2,866.70 in permit fees, $163.40 in tech fees and $258.00 in GPM fees, $3,288.10 in total. The same schedule notes that the Building Division's ADU permit is inclusive of both plan check and permit and all MEPs. The permit-ready packet gives an approximate building permit cost for each plan, from $1,609 for the 306 square foot studio to $2,546 for the 1,198 square foot three-bedroom plan. Impact fees sit outside those amounts. State law bars impact fees on an ADU of 750 square feet or less and on a junior ADU of 500 square feet or less, and any impact fee on a larger unit is charged in proportion to the primary dwelling (Gov. Code Section 66311.5). School districts may charge impact fees on ADUs larger than 500 square feet under Section 17620 of the Education Code, and the city's packet lists development impact and Multi-Species Habitat Conservation Plan fees for ADUs of 750 square feet or larger.

How much does an ADU cost in Menifee?

L Square's configured prefab model prices are $180,000 for Model 600, $240,000 for Models 800A and 800B, $295,000 for Models 1000A and 1000B, and $354,000 for Model 1200. These are configured model prices, not final project totals, and a Menifee lot carries its own line items. A lot on sewer needs a sewer connection permit and fee from Eastern Municipal Water District. A lot on septic may need a new or upgraded system approved by the city's Building and Safety Department and by Riverside County Department of Environmental Health, and parts of the Quail Valley community are under a moratorium on new septic systems. Grading above 50 cubic yards needs a grading plan signed by a licensed engineer, and if the existing home has fire sprinklers the ADU needs them too.

What should I check before building an ADU in Menifee?

Start with the city's ADU ordinance, because the state's housing agency has already weighed in on it. The Department of Housing and Community Development reviewed Menifee Ordinance No. 2024-384, adopted February 7, 2024, and its June 30, 2025 findings letter says the ordinance fails to comply with state ADU law, with a written response due no later than July 29, 2025. The letter points out that a local agency cannot require replacement parking for a converted garage (Gov. Code Section 66314), cannot impose standards beyond state law, and that under Gov. Code Section 66316 an ordinance that fails the state ADU requirements is null and void, so state standards apply until the city adopts a compliant ordinance. Before you submit, confirm the requirement list with city planning staff: hydrant verification, any transmittal to Eastern Municipal Water District or to Riverside County Environmental Health for an onsite waste treatment system, and the electrical and gas releases that stand as occupancy for a single-family residence.

Official Menifee ADU sources

• The City of Menifee publishes eight pre-reviewed, code compliant ADU construction plans in its Permit Ready Accessory Dwelling Unit program. The city lists the sizes as Studio Plan A 415 square feet, Studio Plan B 306 square feet, 1 Bedroom Plan 1A 730 square feet, 1 Bedroom Plan 1B 586 square feet, 2 Bedroom Plan 2A 910 square feet, 2 Bedroom Plan 2B 779 square feet, 3 Bedroom Plan 3A 1198 square feet and 3 Bedroom Plan 3B 988 square feet. The city states the plans are pre-approved by the Building Division, meaning a streamlined permit process and savings on preconstruction fees. Official source
• The City of Menifee ADU Guidebook, dated June 2026, lists development standards for accessory dwelling units: up to one ADU and one JADU per single-family lot; detached maximum unit size 1,200 sq. ft.; attached maximum 1,200 sq. ft. or 50% of the primary residence floor area; one parking space required unless the unit is within half a mile of public transit, is in a historic district, or is created within an existing building; rear and side-yard setback the same as the existing primary dwelling or 4 ft., whichever is less; 800 sf of ADU allowed by-right; a 16 foot height allowed by-right. Official source
• The City of Menifee Permit Ready ADU Application Packet states that the city requires fire sprinklers for an ADU if the existing primary dwelling has fire sprinklers, that a fire apparatus access road is required where any portion of the proposed structure is more than 150 feet from the street property line and can extend to 300 feet with an approved automatic fire sprinkler system, and that a structure less than 600 square feet in area may be exempt from fire protection water supply requirements. Official source
• The City of Menifee Permit Ready ADU Checklist states that the 1st submittal review time is estimated at 10 business days and that all subsequent reviews are estimated at 10 business days, that the Building Technician routes plans to Building, Planning, Engineering and Fire, that a separate grading plan approval and permit from Engineering is required prior to any building permit issuance and is applicable at 50 cubic yards of earthwork, and that the City does not issue Certificates of Occupancy for single-family residences. Official source
• The City of Menifee Building and Safety Permit Fee Schedule effective July 1, 2026 lists the Accessory / Additional Dwelling Unit (ADU) permit at $2,866.70 permit fee, $163.40 tech fee, $258.00 GPM fee and $3,288.10 total, and footnote (1) states that the Building Division's ADU Permit is inclusive of both plan check and permit and all MEPs. Official source
• In a letter dated June 30, 2025, the California Department of Housing and Community Development advised the City of Menifee that the City's ADU Ordinance No. 2024-384, adopted February 7, 2024, fails to comply with State ADU Law, and that the City must provide a written response no later than July 29, 2025. The findings cover zoning, the unit allowance under Government Code section 66323(a), utility connections under section 66324(d), replacement parking under section 66314(d)(11), street-facing exterior stairs, dedication of right-of-way and public improvements. Official source
• California Government Code Section 66317 provides that a permitting agency shall determine whether an accessory dwelling unit application is complete and give written notice of that determination no later than 15 business days after receiving the application, that the agency shall approve or deny the application within 60 days from the date it receives a completed application, and that if the agency has not approved or denied the completed application within 60 days the application shall be deemed approved. Official source
• California Government Code Section 66321 states that a local agency shall not apply any lot coverage, floor area ratio, open space, front setback or minimum lot size rule that does not permit an accessory dwelling unit with at least 800 square feet of interior livable space and with four-foot side and rear yard setbacks to be constructed, and that a local agency shall allow a height of at least 16 feet for a detached accessory dwelling unit on a lot with an existing or proposed single family or multifamily dwelling unit. Official source
• California Government Code Section 66314 states that the total floor area for a detached accessory dwelling unit shall not exceed 1,200 square feet, that the total floor area for an attached accessory dwelling unit shall not exceed 50 percent of the existing primary dwelling, that a setback of no more than four feet from the side and rear lot lines shall be required, and that parking requirements shall not exceed one parking space per accessory dwelling unit or per bedroom, whichever is less. Official source
• California Government Code Section 66311.5 states that a local agency, special district or water corporation shall not impose any impact fee upon the development of an accessory dwelling unit that has 750 square feet of interior livable space or less, or a junior accessory dwelling unit that has 500 square feet of interior livable space or less, and that any impact fees charged for an accessory dwelling unit with more than 750 square feet of interior livable space are charged proportionately in relation to the square footage of the primary dwelling unit. Official source