IL Total Design and Build
Escondido
- Active license
- Bond on file
- Insured
- 7 yrs licensed
ADU builders and rules in La Mesa
La Mesa ADU rules allow up to 1,200 sq ft, require no parking for any ADU, and come with five city pre-approved plans and a $2,000 fee waiver. Here's what the city's ordinance and development matrix say, and how to apply.
La Mesa ADU facts
- Max ADU size
- 1,200 sq ft
- Height limit
- 20 ft in single-family zones
- ADU parking
- None required
- Pre-approved plans
- 5 city plans, 224 to 1,199 sq ft
- Fee waiver
- First $2,000 of city fees
- City Hall
- 8130 Allison Ave., 619-463-6611
Verified ADU builders serving La Mesa
All San Diego County buildersNone of our verified builders is based in La Mesa yet; these work across San Diego County. Each holds an active B license with a bond on file, checked with the state on Oct 26, 2026.
Adama Builders
San Diego
- Active license
- Bond on file
- Comp exempt
- New license
Snap ADU
San Diego
- Active license
- Bond on file
- Insured
- 5 yrs licensed
GW Construction
San Diego
- Active license
- Bond on file
- Insured
- 2 yrs licensed
EG Construction
Chula Vista
- Active license
- Bond on file
- Comp exempt
- 21 yrs licensed
Eco Home Builders Inc
San Diego
- Active license
- Bond on file
- Insured
- 5 yrs licensed
La Mesa ADU ordinance and rules
La Mesa's ADU ordinance is Municipal Code § 24.05.020D8, last rewritten by Ordinance No. 2023-2903, adopted March 14, 2023. The city summarizes the current standards, including state law changes since then, in its ADU and JADU development matrix, updated in June 2026. These are the city of La Mesa ADU requirements for single-family zones (R1E, R1R, R1S, R1 and R1A).
| Rule | La Mesa |
|---|---|
| Number of ADUs | Up to 3 ADUs per lot (one under city standards, one conversion, one detached up to 800 sq ft), plus 1 junior ADU |
| Detached ADU size | Up to 1,200 sq ft, or up to 800 sq ft under the state-law option |
| Attached ADU size | No more than 50% of the existing house |
| Junior ADU | Up to 500 sq ft inside the house; owner must live on site if it shares a bathroom |
| Height | 20 ft, measured from finished grade to the top plate |
| Setbacks (new detached) | Front setback of the zone; 4 ft side and rear |
| Lot coverage | 40% |
| Parking | No new, additional or replacement spaces required |
| Owner occupancy | None for ADUs |
| Rentals | Terms longer than 30 days |
| Fire sprinklers | If the house has them, or if the rear of the ADU is 150 ft or more from the curb |
The parking rule is the standout. Many cities still require a space unless you're near transit; La Mesa's 2023 ordinance dropped ADU parking entirely and doesn't make you replace a garage you convert. The same ordinance adds five percent of lot coverage for ADUs on lots of 10,000 sq ft or less with an existing house, and says no coverage, front setback, open space or lot size rule can block an 800 sq ft ADU with 4-ft side and rear setbacks. It also exempts ADU-only projects from the Urban Design Overlay Zone; projects in the Scenic Preservation and Hillside overlays still follow those rules, but skip Planning Commission review.
The city's ADU guidebook explains how lot coverage limits size: below the maximum you can usually build up to 1,200 sq ft, while at or above it you may be held to 800 sq ft. See California ADU laws for the state rules behind this, and our junior ADU guide for JADUs.
La Mesa pre-approved ADU plans
La Mesa offers five pre-approved ADU plans on its website. You still add a site plan, Title 24 energy calculations and other project-specific documents.
| Plan | Size | Layout |
|---|---|---|
| Plan A | 224 sq ft | Studio |
| Plan B | 400 sq ft | One bedroom |
| Plan C | 499 sq ft | One bedroom |
| Plan D | 990 sq ft | Two bedroom |
| Plan E | 1,199 sq ft | Three bedroom |
To use one, pick a plan, email Planning@cityoflamesa.gov for the official construction permitting set, prepare your site plan and supplemental documents (a soils report only if the ADU is over 500 sq ft), fill in the project details on the plan set and submit it through the permit portal. The city also points homeowners to the County of San Diego's free ADU plans, which can be adapted to La Mesa's submittal requirements. Compare options in our pre-approved ADU plans guide.
La Mesa ADU fees
| Fee | What applies |
|---|---|
| City fee waiver | First $2,000 of city fees waived for ADU and JADU building permits (FY 2024–25 schedule) |
| Impact fees | None under 750 sq ft; above that, proportional to the main house |
| Park and RTCIP fees | ADU-only projects pay no park fees, and the first ADU or JADU on a lot pays no regional transportation (RTCIP) fee |
| Junior ADU covenant | $125 (Planning fee in the same schedule) |
The waiver applies only to city fees. You still pay other agencies, such as water and school districts, in full, and their fees are calculated before the waiver. A conversion inside the house or an existing accessory structure usually needs no separate utility connection or connection fee. The 750 sq ft impact-fee threshold comes from state law. School developer fees are set by your school district, so ask it for the current rate. For build costs, see what an ADU costs in San Diego or use the ADU cost calculator.
Fees update every year. The $2,000 waiver has been in place since July 1, 2022 and was still in the FY 2024–25 fee schedule, the latest we could read. Ask the Building Division to confirm it before you budget.
Getting a La Mesa ADU permit
La Mesa takes ADU and JADU applications online through the MaintStar portal. City Hall is at 8130 Allison Avenue, phone 619-463-6611, per the city's ADU page. Once your application is complete, state law gives the city 60 days to approve or deny it.
Demand is steady: the guidebook reports 223 ADU permits from 2018 to 2022, 61 of them in 2022, with an average size around 660 sq ft, and a plan for about 80 a year through 2029. Before you sign a contract, read how to hire an ADU contractor, check a contractor's license, and compare verified ADU builders in San Diego County.
Common questions
Does La Mesa have pre-approved ADU plans?
Yes. La Mesa offers five pre-approved plans from a 224 sq ft studio to a 1,199 sq ft three-bedroom. Email Planning for the permit set, add a site plan and energy calculations, and submit online.
How big can an ADU be in La Mesa?
Up to 1,200 sq ft. An attached ADU can't exceed 50% of the existing house, and a junior ADU is limited to 500 sq ft.
Do I need parking for an ADU in La Mesa?
No. La Mesa requires no new, additional or replacement parking for ADUs, even if you convert a garage.
What does the La Mesa ADU ordinance say about renting?
There's no owner-occupancy rule for ADUs, but rentals must be longer than 30 days. A junior ADU that shares a bathroom requires the owner to live in the house or the JADU.
What are La Mesa ADU fees?
La Mesa waives the first $2,000 of city fees on ADU and JADU permits. ADUs under 750 sq ft pay no impact fees, ADU-only projects pay no park fees, and the first ADU on a lot pays no RTCIP fee.
Sources
- City of La MesaAccessory Dwelling Units
- City of La MesaADU and JADU Development Matrix (June 2026)
- City of La Mesa (Municode)Ordinance No. 2023-2903, ADU amendments to Title 24 (adopted March 14, 2023)
- City of La MesaAccessory Dwelling Unit Guidebook (February 2023)
- City of La MesaFee Schedule, Fiscal Year 2024–2025
- City of La MesaMaintStar permitting portal
- County of San Diego Planning & Development ServicesAccessory Dwelling Unit Plans
- California Legislative InformationGovernment Code § 66311.5 (fees)
- California Legislative InformationGovernment Code § 66317 (permit timelines)
General information, updated Oct 26, 2026. Rules and fees change; confirm with the La Mesa permit office before you rely on them.