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

What do the Lake Elsinore permit-ready ADU plans include?

The city's Permit Ready Accessory Dwelling Unit program publishes three pre-reviewed, code-compliant construction plans: a new ADU of 495 square feet, a new ADU of 735 square feet, and a 400 square foot plan for converting an existing garage into a dwelling. The Building and Safety Division has pre-approved the set, so an application built on one of these plans normally skips the building plan check and the plan check fees. The permit itself is still required, and the application still goes to Planning, Engineering, Building and Fire. Minor edits are allowed, such as swapping exterior materials, adding outlets, changing door or window styles and reversing the plan to fit the lot, while structural changes or a change of size send the project back into plan check.

How long does Lake Elsinore take to review an ADU permit?

The city estimates about ten business days for a first review and five business days for a second review on a permit-ready plan application, with Planning, Engineering, Building and Fire reviewing the plans. State law sets the outer clock and the backstop. A permitting agency must say in writing whether the application is complete within 15 business days, and must approve or deny a complete application within 60 days from the date it receives it. If the city has not acted on a complete application in 60 days, the application is deemed approved, and an applicant-requested delay tolls that clock (Gov. Code Section 66317).

What does an ADU permit cost in Lake Elsinore?

Expect a valuation-based building permit fee plus a $40.00 issuance fee and a $5.00 professional development fee on each permit, with plan check set at 75% of the building permit fee. The current Building and Safety fee schedule, set by City Council Resolution No. 2026-032 and revised 07/01/2026, also lists a $570.00 special inspection, a $120.00 per hour re-inspection fee, a $125.00 per hour fee for additional plan review after changes or revisions, and $210.00 per hour for inspections outside normal business hours. Impact fees sit outside those amounts: state law bars impact fees on an ADU of 750 square feet or less, and a larger unit is charged in proportion to the primary dwelling (Gov. Code Section 66311.5).

How much does an ADU cost in Lake Elsinore?

L Square publishes configured prefab unit prices: $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 unit prices, not a final project total for a specific house. A Lake Elsinore quote also carries the site work your lot needs, such as grading and retaining on a sloped pad, a drainage plan, the utility connection work and any structural engineering. Write those line items into the proposal so you can see what the terrain adds.

What should I check on my Lake Elsinore lot before building an ADU?

Check the city's review path and your utilities first, because Lake Elsinore changed how ADU applications are processed as of January 2026. The Zoning Compliance Planning Check is no longer required for SFD, ADUs and additions, and those applications go through the Building Division instead. The Planning Division still reviews additions, with additions of less than 600 square feet approved over the counter by planners and larger additions requiring Administrative Design Review and approval by the Community Development Director. On the lot itself, confirm where water and sewer service comes from, whether the unit can use the existing utility lines, and whether the pad needs a grading permit, because the city's engineering department makes that call during review.

Is the City of Lake Elsinore's ADU ordinance compliant with California law?

No. In a letter dated August 20, 2025, the Department of Housing and Community Development told the City of Lake Elsinore that the city's ADU ordinance does not comply with state ADU law, and that the city had said it would process ADU applications under state law alone until it adopts a new ordinance. The department's point is that using state law without repealing the old ordinance does not satisfy Gov. Code Section 66326, subdivision (b), so the city should repeal it and remove public-facing materials that do not match state law. Until a compliant ordinance is in place, plan against the state standards: at least 800 square feet of interior livable space with four-foot side and rear yard setbacks, a detached ADU that does not exceed 1,200 square feet, and a height of at least 16 feet.

Official Lake Elsinore ADU sources

• The City of Lake Elsinore's Permit Ready Accessory Dwelling Unit program offers three pre-reviewed, code-compliant ADU construction plans with customizable options for exterior finishes. The plans are pre-approved by the Building and Safety Division, which the city says means a streamlined permit process and significant savings on preconstruction fees, and the LE Permit Ready ADU Packet includes the application, the indemnification form, an overview of fees and step-by-step instructions for the submittal. Official source
• The city's Permit Ready ADU instructions say the program provides three pre-reviewed and code-compliant ADU construction plans that residents can obtain for free, that it eliminates the need for plan check and plan check fees but not the need for a permit or for Planning, Engineering and Fire review, and that the first review takes approximately ten business days and the second review five business days. They also require fire sprinklers if the existing primary dwelling has them, and require solar on all new detached ADUs. Official source
• The City of Lake Elsinore Building and Safety Division fee schedule states that all fees are set by City Council Resolution No. 2026-032 and revised 07/01/2026. It lists an issuance fee of $40.00 for each permit, a professional development fee of $5.00 for each permit, inspections outside normal business hours at $210.00 per hour, a re-inspection fee of $120.00 per hour, additional plan review after changes, additions or revisions to approved plans at $125.00 per hour, and a special inspection at $570.00. Official source
• The city explains that building permit fees are derived by assigning a valuation to the project, which is the square footage of the project multiplied by the valuation factor. A percentage of that valuation becomes the Building Permit Fee, and 75% of the Building Permit Fee becomes the Plan Check Fee. The same page lists the 2025 MSHCP Fee Schedule, the Chart of Building Permit Fees, and separate city electrical, mechanical, plumbing and development impact fee schedules. Official source
• The city's FAQ states that as of January 2026 the Zoning Compliance Planning Check is no longer required for SFD, ADUs and additions, and that these can be submitted through the Building Division, with a Preliminary Planning Review Application available for plan check. It also states that the Planning Division reviews all additions, that additions of less than 600 square feet are reviewed and approved over the counter by planners, and that additions of more than 600 square feet require Administrative Design Review and approval by the Community Development Director. Official source
• The city's Permits and Inspection page states that an owner or authorized agent who intends to construct, enlarge, alter or change the occupancy of a building must first make application to the building official and obtain the required permit, that online applications for building permits are available, and that work must remain accessible and exposed for inspection until approved. It says inspection calls received before 5 pm on a workday will be scheduled for the next available workday. Official source
• In a letter dated August 20, 2025, the California Department of Housing and Community Development advised the City of Lake Elsinore that the city's ADU ordinance does not comply with state ADU law, that the city had said it intends to exclusively use state ADU law to process ADU applications until it adopts a new ordinance, and that doing so does not satisfy Gov. Code Section 66326, subdivision (b). The letter says the city should repeal the outdated ordinance and that public-facing materials such as fact sheets and webpages should match state ADU law or must be removed. Official source
• California Government Code Section 66317 provides that a permitting agency shall approve or deny an accessory dwelling unit application within 60 days from the date it receives a completed application, that if the agency has not approved or denied the completed application within 60 days the application shall be deemed approved, and that if the applicant requests a delay the 60-day period is tolled for the period of the delay. It also requires written notice of completeness no later than 15 business days after the application is received. Official source
• California Government Code Section 66321 provides 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 provides that the total floor area for a detached accessory dwelling unit shall not exceed 1,200 square feet, that 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, that parking requirements shall not exceed one parking space per unit or per bedroom, whichever is less, and that the local agency shall not require replacement parking when a garage is converted. Official source
• California Government Code Section 66311.5 provides 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