Custom home builders in Contra Costa County, CA
No contractors are listed for new-home work in Contra Costa County yet. CSLB license data dated Oct 16, 2026.
Which license do you need?
B license required. Building a new house takes a B (General Building) license, which covers structures "built, being built, or to be built" with two or more unrelated trades. A B-2 is limited to existing homes and can't build new.
Do you need a permit?
Check with Contra Costa County first. The County does planning review only for unincorporated Contra Costa, but it also issues building permits for Clayton, Hercules, Lafayette, Moraga and Orinda.
Source: Contra Costa County, Department of Conservation and Development, Oct 18, 2026
New home contractors in Contra Costa County
No contractors listed here yet.
We list contractors here only when city permit records or the contractor show they do new homes. None so far. For a wider set of licensed builders, see the Contra Costa County general contractor list and ask each for new-home projects they've finished.
Payment doesn't change the order. Business build-out? See commercial GCs. Each card shows CSLB data from the file dated Oct 16, 2026. Verify live on CSLB.
Permits in Contra Costa County
Permits go through Contra Costa County Department of Conservation and Development, Building Inspection. Put in the contract who pulls the permit.
Almost every project needs a County permit, including electrical panel upgrades, pergolas, outdoor kitchens and retaining walls of 3 ft or more. Planning approval comes first for a new ADU or any change to a building's size, height or exterior.
Source: Contra Costa County, Department of Conservation and Development, checked Oct 18, 2026
Building, Planning and Public Works applications are filed 100% digitally through the ePermits Center; paper is no longer accepted.
Source: Contra Costa County, Department of Conservation and Development, checked Oct 18, 2026
The completeness check takes about 4 to 5 business days. Larger projects then pay a plan check fee, and review starts once payment is confirmed.
Source: Contra Costa County, Department of Conservation and Development, checked Oct 18, 2026
Owner-builders, including a trust or corporation, can pull County permits by filing a Building Permit Declaration form, and may need to show proof of ownership.
Source: Contra Costa County, Department of Conservation and Development, checked Oct 18, 2026
What a new-home job costs
Too few new-home permits in Contra Costa County declare a value for us to publish a range. For an estimate by size and finish level, use the home construction cost calculator.
B or B-2: which license fits your job
Both classes can act as your prime contractor. A B-2 is limited to remodels of an existing wood-frame house. If your plan changes the structure, look for a B.
| Job | B General Building | B-2 Residential Remodeling |
|---|---|---|
| Kitchen or bath remodel in an existing house | Yes | Yes, when the contract covers 3 or more unrelated trades |
| Addition or new rooms | Yes | No |
| Moving or removing a load-bearing wall | Yes | No |
| New home | Yes | No |
| Commercial or tenant work | Yes | No |
Sources: CSLB, class B and class B-2, checked Oct 18, 2026. More in B vs B-2.
California rules for your contract
A down payment on a home improvement contract can't be more than $1,000 or 10% of the price, whichever is less. No progress payment can be more than the work done or materials delivered.
Source: California B&P Code 7159.5, checked Oct 18, 2026
Work under $1,000 in total (labor and materials) that needs no building permit doesn't require a license. The exemption doesn't apply if the person advertises as a contractor, has employees, or splits a job to stay under the limit.
Source: California B&P Code 7048, checked Oct 18, 2026
Every licensed contractor must keep a $25,000 contractor's bond on file with CSLB. That has been the amount since January 1, 2023.
Source: CSLB, bond requirements, checked Oct 18, 2026
A contractor with employees must carry workers' comp. Until 2028, a B contractor with no employees can legally file an exemption, so check which one yours did. From January 1, 2028, a workers' comp certificate is required for every license.
Source: CSLB, workers' compensation, checked Oct 18, 2026
Complaint history isn't in CSLB's free data files, so we don't show it. Check complaints on CSLB before you sign.
Custom home builders near Contra Costa County
Other project types in Contra Costa County
How this list is built
We have no city permit file for Contra Costa County yet, so a contractor is listed only if it confirmed new-home work to us. A contractor is listed only with evidence for new-home work: a permit record whose description matches, or a source the contractor gave us.
License class, status, dates, bond and workers' comp come from CSLB's public data files: Master file Oct 16, 2026, workers' comp file Oct 17, 2026, processed Oct 18, 2026. Each card links to that license's live CSLB record. Full method.