Remodeling & ADU Contractor in Brea

Brea grew up around oil, and that history still shows up in permits for remodels and ADUs. IA Builders is a licensed California general contractor (CSLB #1124696) based in Culver City, and we handle remodels, room additions and ADUs across Orange County, Brea included. Before design starts on a Brea project, we check the lot for methane zones, hillside zoning and fire hazard areas, because those can change the plan.

From oil town to suburb

The city's history traces Brea to the Brea-Olinda oil field, where drilling began in 1896. The city incorporated in 1917, and Union Oil set aside streets near the city center for worker tract homes. The oil boom faded by the 1940s, and the citrus groves gave way to new tracts in the 1950s. The SR-57 freeway and Brea Mall arrived in the 1970s, and whole new neighborhoods were built through the 1970s and 1980s. More recently, three master-planned developments have added more than 2,000 homes, among them neighborhoods in the northern hills such as Olinda Ranch.

Because of that, Brea has homes from almost every era, and they need different things:

• Older homes near downtown often need a whole-home remodel with updated electrical, plumbing and framing along with a new layout.
• Post-war and 1970s–80s houses are good candidates for a kitchen remodel that opens up the floor plan, or a bathroom remodel that replaces original fixtures.
• Single-story homes on larger lots often have room for a room addition.

Many newer neighborhoods have homeowners associations, so exterior work needs association approval in addition to the city permit.

Permits in Brea

Building permits are handled by the Building & Safety Division of Brea's Community Development Department, and plans are also routed to Planning, Public Works and the Fire Department. The city accepts building permit applications through its online permit center and takes electronic submittals only. We prepare the drawings, submit them and respond to plan check comments for you.

Some parts of Brea come with extra steps:

• Methane zones. Brea sits on a historic oil field, and the city maps methane zones on its online GIS system. A lot in a methane zone cannot use the city's pre-approved ADU plans, and we confirm with Building & Safety what else applies before designing new construction there.
• Hillside zoning. Homes in Brea's Hillside Residential zone may need a hillside development permit for new construction, and the city notes that hillside ADU projects may need civil drawings and a geotechnical report.
• Wildfire zones. Carbon Canyon covers about 1,758 acres and is part of Brea's wildland-urban interface, according to the city's wildfire safety page. In 2025 the city adopted updated Fire Hazard Severity Zone maps and the 2025 California Wildland-Urban Interface Code, with local amendments that include updated brush clearance standards. In those zones, additions and ADUs have to use fire-resistant materials and meet defensible space rules.

ADUs in Brea

Brea issued 25 building permits for ADUs in 2025, according to its General Plan progress report, and the city promotes ADUs as multigenerational and more affordable housing. It also runs a Pre-Approved ADU Plans Program, where designers get plans approved in advance and homeowners work with a listed designer to adapt one to their lot.

To use a pre-approved plan, the property cannot be in a methane zone or flood zone. Lots in a hillside zone, Very High Fire Hazard Severity Zone or liquefaction zone may face extra restrictions, and every plan still needs site-specific documents such as an updated site plan and Title 24 energy calculations. A soils report or proof of compliance with the city's foundation policy may also be required. The city recommends talking with Building & Safety staff before applying, and so do we. We can help you weigh a pre-approved plan against a custom ADU, junior ADU or garage conversion once we know what applies to your lot.

If you own a home in Brea and are planning a project, call (213) 816-6465 or use the form on this page.

Frequently asked questions

Who issues building permits in Brea?

The City of Brea's Building & Safety Division, part of the Community Development Department. Applications are submitted electronically, and plans also go to Planning, Public Works and Fire for review.

Can I use one of Brea's pre-approved ADU plans?

If your property is not in a methane zone or flood zone, possibly. Hillside, Very High Fire Hazard Severity Zone and liquefaction-zone lots may face extra restrictions, and every pre-approved plan still needs site-specific documents.

Does living in Carbon Canyon or the hills change my project?

Often, yes. Hillside lots may need a hillside development permit, civil drawings and a geotechnical report, and homes in fire hazard zones must meet wildland-urban interface building standards and brush clearance rules.

Why does a methane zone matter for my Brea remodel?

Parts of Brea sit on a historic oil field, and the city maps methane zones. A lot in a methane zone cannot use the city's pre-approved ADU plans, so we check the zone and confirm any other requirements with Building & Safety before designing an addition or ADU.

Last reviewed October 2026