Costa Mesa Building Permits Guide for Homeowners and Sellers

Last updated November 13, 2026. Reviewed by the Cash Home Buyers CA team. Information comes from the City of Costa Mesa; sources are listed at the end.

Costa Mesa takes building permit applications through its TESSA online portal, and the city says paper applications and scanned copies are ignored. Knowing how the city handles permits helps you check whether past work on a house was permitted before you sell.

Costa Mesa building permits at a glance

How do I check permits on a Costa Mesa property?

Start with the address. Ask Building Safety at (714) 754-5273 how to view past permit records for the property, and look for permits that match any addition, converted garage, pool or remodel you can see. If work shows up with no permit on file, treat it as unpermitted work.

Why does unpermitted work matter in Costa Mesa?

The city’s code enforcement staff enforce building permit rules under California Building Code Section 105.1, so work done without a permit can lead to a case. See our Costa Mesa code enforcement guide for how a complaint starts.

How permits affect selling a house in Costa Mesa

In California, sellers generally have to disclose known problems, including work you know was done without a permit. On a traditional sale, buyers often ask for a closed-out permit, repairs or a price cut. A cash buyer can purchase the house with the permit problem unresolved and price the risk into the offer.

How to sell a house in Costa Mesa with unpermitted work or open permits

1. Check the city record. Ask Building Safety what is on file for the address.
2. List what you know. Who did the work, when, and whether you have receipts or plans.
3. Compare your options. Finish the permit, sell with a price credit, or sell as-is to a cash buyer.
4. Disclose honestly. A cash offer does not change what you must disclose, but it removes the repair and inspection steps that cause delays.

We buy Costa Mesa houses as they are. Read how selling a house as-is in Costa Mesa works, or see our Costa Mesa cash-offer process. For backyard units, see our Costa Mesa zoning and ADU guide.

Not sure what your permit history means for a sale? Call (424) 435-2326 or request a cash offer. There is no cost and no obligation.

Matching the TESSA permit list to your house

The city’s building permits page sorts residential work into permit types, and that list is a handy checklist for a pre-sale walk-through.

It names residential additions and alterations, ADU new construction and conversion, junior ADUs, pools, roofing, solar, electrical, plumbing, mechanical, patio covers, block walls and fences, and windows and doors. Walk the property with that list in hand and note each item that exists on your lot.

A block wall, a patio cover and a replaced water heater are all things buyers’ inspectors notice, and each has its own permit type in Costa Mesa.

The city also lists separate Insta-Permit types for small residential jobs such as re-roofs, water heaters, panel upgrades, HVAC and EV chargers, with one version for licensed contractors and another for owner-builders.

Why that matters to a seller: the same job can be permitted by a contractor or by a prior owner acting as owner-builder, so the name on an old permit may be a previous owner rather than a company.

A mismatch between what you were told when you bought and what the record shows is worth raising with Building Safety.

Questions to ask Building Safety at (714) 754-5273

• Which permits are on file for my address, and which show as finaled?
• Are any permits open or expired, and what would it take to close them?
• If I find work without a permit, what does the city require to legalize it?
• Does a converted garage or added room need to go through the ADU process or the residential addition process?
• Can I get copies of approved plans for past work?

Write down the answers with the date and the staff member’s name. If a buyer or lender later questions the house, a dated note of what the city told you carries more weight than a recollection.

What a buyer’s inspection tends to find

Inspectors look for signs that do not fit the paperwork: an electrical panel that is newer than any permit on file, a patio cover with no matching record, plumbing in a converted space, or a pool with no final. These findings rarely stop a sale outright.

They turn into requests for repairs, credits or a closed-out permit, and each request adds time to a traditional closing. If you would rather not manage that process, a cash sale lets you skip it, and our California as-is and unpermitted work guide explains disclosure either way.

Permits, taxes and costs to keep in mind

Permitted improvements can change what a county assessor records for your property, so a recent addition may matter to the tax picture a buyer sees. Our Orange County property tax guide explains bills and deadlines, and the seller closing costs guide shows what a traditional sale usually costs you before any permit work.

More Costa Mesa permit questions

Can an owner pull their own permit in Costa Mesa?

The city lists owner-builder versions of its Insta-Permit types for small jobs such as re-roofs and water heaters, alongside licensed-contractor versions.

What should I do if I find work with no permit on file?

Call Building Safety at (714) 754-5273, ask what legalizing would require, and disclose the work if you sell.

Does a garage conversion need a permit in Costa Mesa?

Converted living space is normally handled through the city’s permit process or its ADU rules, so confirm with the Planning Division or Building Safety before assuming it is fine.

Costa Mesa building permits FAQ

How do I apply for a building permit in Costa Mesa?

Enter the application directly in the city’s TESSA portal. The city says paper forms and uploaded scans of paper applications will be ignored.

Does Costa Mesa have quick permits for small jobs?

The city lists Insta-Permit types for some residential work such as re-roofs, water heaters, panel upgrades, HVAC and EV chargers, with separate options for licensed contractors and owner-builders.

Can I sell a house in Costa Mesa with an open permit?

Yes. An open permit does not legally stop a sale, but it can slow a traditional one. A cash buyer can purchase the house with the permit still open.

How do I sell a house in Costa Mesa with unpermitted additions?

Disclose the work, then choose between permitting it, discounting the price, or selling as-is to a cash buyer who accounts for the risk in the offer.

Sources

• City of Costa Mesa: Building Permits
• City of Costa Mesa: Code Enforcement

This guide is general information, not legal advice. Permit rules change; confirm requirements with the City of Costa Mesa.