| B & B Locksmith And Security INC | Oleg Alex Berger | — | (415) 423 0182 | Alarm and generators | Walnut Creek · Contra Costa County | — | — |
| B & C Garage Door INC | Bruce Stephen Cameron | info@bcgaragedoors.ca | (925) 828 1999 | Other | San Ramon · Contra Costa County | — | — |
| B & D Contractor | B & D Contractor | — | (510) 776 2156 | Other | El Sobrante · Contra Costa County | — | — |
| B & H Plumbing & Home Services INC | William John Hicks | — | (925) 833 7110 | GC, remodel, ADU | San Ramon · Contra Costa County | — | — |
| B & H Services | William John Hicks | — | (925) 833 7110 | GC, remodel, ADU | San Ramon · Contra Costa County | — | — |
| B & J Home Remodeling | William Ray Cutrufelli | — | (925) 787 0438 | GC, remodel, ADU | Orinda · Contra Costa County | — | — |
| B & M Tear Off INC | Bernal Felipe | — | (925) 679 8413 | Other roofers | Knightsen · Contra Costa County | — | — |
| B & N Carpet Service | Geraldine Sue Burrow | — | (510) 417 5555 | Other | El Sobrante · Contra Costa County | — | — |
| B & R Construction Company | David Michael Lee | — | (925) 286 4400 | GC, remodel, ADU | Martinez · Contra Costa County | — | — |
| B & V Builders | B & V Builders | — | (925) 383 0609 | GC, remodel, ADU | Concord · Contra Costa County | — | — |
| B - Dang's Landscaping INC | Dang Be | — | (925) 778 9187 | Windows, patio, painters | Antioch · Contra Costa County | — | — |
| B 3 Finish Carpentry LLC | Branden Welch Floryancic | — | (510) 962 2540 | Other | Martinez · Contra Costa County | — | — |
| B A I Construction | Behnam Afshar | — | (415) 725 9599 | GC, remodel, ADU | Orinda · Contra Costa County | — | — |
| B And K Roofing INC | Terry Wayne Montgomery | — | (925) 625 1243 | Other roofers | Antioch · Contra Costa County | — | — |
| B B C Construction | Craig Kent Hermann | — | (925) 383 2908 | GC, remodel, ADU | Walnut Creek · Contra Costa County | — | — |
| B B S Masonry | B B S Masonry | — | (925) 765 6080 | Other | Concord · Contra Costa County | — | — |
| B C Mccosker Construction INC | Nicholaus D Northern | — | (925) 686 1780 | GC, remodel, ADU | Concord · Contra Costa County | — | — |
| B Cook Construction | Brent Edward Cook | — | (925) 872 0889 | GC, remodel, ADU | San Ramon · Contra Costa County | — | — |
| B Cool Express Heating & Air Conditioning | Bonifacio Fajardo De Dios | — | (925) 300 8248 | HVAC | Antioch · Contra Costa County | — | — |
| B D M Electrical Contractor | Benjamin David Manuel | — | (925) 676 1800 | Electricians | Martinez · Contra Costa County | — | — |
| B E Builders | B E Builders | info@bebuilders.com | (925) 260 4535 | GC, remodel, ADU | Concord · Contra Costa County | — | — |
| B F Electric | Ferguson Brion | — | (510) 435 5643 | Electricians | Richmond · Contra Costa County | — | — |
| B I Quality Painting | Okun Boris | — | (415) 317 3005 | GC, remodel, ADU | Pleasant Hill · Contra Costa County | — | — |
| B K Construction Company | Bruce Woohyok Kang | — | (650) 380 8538 | GC, remodel, ADU | El Sobrante · Contra Costa County | — | — |
| B K Glass Shower & Window | Brendan Loren Koravos | — | (925) 817 9171 | Windows, patio, painters | Discovery Bay · Contra Costa County | — | — |
| B L S Contractors Incorporated | Paul Elijah Sr Pollino | — | (925) 825 8212 | Other roofers | Concord · Contra Costa County | — | — |
| B L Williams Custom Homes | B L Williams Custom Homes | — | (925) 360 5345 | GC, remodel, ADU | Concord · Contra Costa County | — | — |
| B M B Service And Supply | Bruce Merrill Baudean | — | (650) 690 6099 | GC, remodel, ADU | Crockett · Contra Costa County | — | — |
| B M T Construction And Maintenance INC | Jeffery Orland Reed | — | (925) 381 1419 | GC, remodel, ADU | Concord · Contra Costa County | — | — |
| B P Lopez Landscape INC | Juanito Boni Hernandez Lopez | — | (707) 548 9884 | Windows, patio, painters | San Pablo · Contra Costa County | — | — |
| B Pico Construction | Brent William Pico | — | (925) 382 5291 | GC, remodel, ADU | Oakley · Contra Costa County | — | — |
| B R W Development | B R W Development | — | (925) 301 5508 | GC, remodel, ADU | Brentwood · Contra Costa County | — | — |
| B Schreiner Construction Company | Brett Gordon Schreiner | — | (510) 812 4131 | Other | Briones · Contra Costa County | — | — |
| B W D Gardens INC | Brian Wilson Whyte | info@bwdgardens.com | (510) 280 3824 | Windows, patio, painters | Richmond · Contra Costa County | — | — |
| B W Engineering | B W Engineering | — | (714) 540-9975 | GC, remodel, ADU | Pinole · Contra Costa County | — | — |
| B Z Builders | B Z Builders | — | (925) 640 5190 | GC, remodel, ADU | Concord · Contra Costa County | — | — |
| B Z Refrigeration | B Z Refrigeration | — | (925) 381 3195 | HVAC | Pacheco · Contra Costa County | — | — |
| B/e Heating And Cooling INC | Alvaro Sarbelio Bonilla Cubias | — | (925) 435 2155 | HVAC | Bay Point · Contra Costa County | — | — |
| Badger Construction | John Charles Badger | — | (925) 286 2949 | GC, remodel, ADU | Pleasant Hill · Contra Costa County | — | — |
| Bahman Soleimani Noori | Bahman Soleimani Noori | — | (925) 658 2131 | GC, remodel, ADU | San Ramon · Contra Costa County | — | — |