ADUs & Additions in Costa Mesa

City of Costa Mesa Economic and Development Services Department, Building Safety Division. Building permits here are not issued by a community development department — they come from the Building Safety Division inside the Economic and Development Services Department, at 77 Fair Drive. Plan submittal, permit issuance and fee payment run through the city's TESSA portal, and a limited set of simple scopes qualify for the city's Insta-Permit program instead of full plan check. Plan check appointments are scheduled by phone or email through the Building Safety counter. Pools, spas, additions and ADUs go through standard plan review, and the city publishes weekly issued-permit listings and a document search for pulling permit history on an existing property before scoping a remodel. We prepare the drawings, make the submittal and handle plan-check corrections ourselves, so you are not the one chasing the city.

Flat, regular postwar tract lots, commonly around six thousand square feet with a wide street frontage and a shallow but usable rear yard. Eastside parcels vary more, with some deeper original lots and mixed-era infill. In practice that means most housing stock dates from the late 1940s through the 1960s, so cast-iron and galvanized drain lines, undersized panels and original slab penetrations surface routinely once demolition starts..

All of it, including Eastside Costa Mesa, Mesa Verde, Mesa del Mar, College Park. We are based in Los Angeles at Cahuenga Pass, so Costa Mesa is a short run for our crews rather than a job we service from out of the area.

Detached ADU in this market generally runs $150,000 to $400,000+. What moves it is square footage, finish level, utility runs, and site access; garage conversions typically run well below a ground-up detached build. We give line-item pricing after seeing the site rather than quoting a number over the phone.

Plan a realistic year. Design and engineering typically take one to three months, city plan check and corrections add several more, and construction usually runs four to eight months depending on size and site access.

Usually yes, and often substantially, because the foundation, walls and roof already exist. The trade-offs are that you lose the garage, and older slabs and framing sometimes need upgrading to meet current code.

California ADU law is designed to allow long-term rental, and an ADU is one of the few ways to add rentable square footage to a single-family lot. Short-term rental rules vary by city, so confirm your local ordinance before counting on that income.

Yes. Plans, engineering, Title 24 and the city submittal are all handled in-house, including responding to plan-check corrections. That is a service we sell on its own, so it is not something we hand off.