| Bennett Electric INC | Christopher Primo Bennett | — | (925) 250 3871 | Electricians | Martinez · Contra Costa County | — | — |
| Bentley Electric | Richard Joseph Bentley | — | (510) 367 9247 | Electricians | Lafayette · Contra Costa County | — | — |
| Benz Architecture And Consulting | Benz Architecture And Consulting | — | (707) 246 7675 | GC, remodel, ADU | Walnut Creek · Contra Costa County | — | — |
| Berkeley Construction Group INC | Danilo Bosio | info@berkeleyconstructiongroup.com | (510) 859 5800 | GC, remodel, ADU | El Sobrante · Contra Costa County | — | — |
| Berland Design | Berland Design | info@berlanddesign.com | (738) 834 3093 | Other | Richmond · Contra Costa County | — | — |
| Bernal's Painting | Bernal's Painting | — | (510) 367 6781 | Windows, patio, painters | Martinez · Contra Costa County | — | — |
| Bernard Construction Co INC | Bernard Pui Yuen Wu | — | (408) 892 0761 | GC, remodel, ADU | San Ramon · Contra Costa County | — | — |
| Berrett Homes | Berrett Homes | — | (925) 570 7070 | GC, remodel, ADU | Concord · Contra Costa County | — | — |
| Bertolini Construction | Brendan Scott Bertolini | — | (925) 768 3956 | GC, remodel, ADU | Antioch · Contra Costa County | — | — |
| Bespoked Contractors INC | Michael Francis Seaton | — | (510) 339 3863 | GC, remodel, ADU | Orinda · Contra Costa County | — | — |
| Best And Local Garage Door Service | Bar On Adi | — | (800) 474 6498 | Other | Pleasant Hill · Contra Costa County | — | — |
| Best Bet Painting | Best Bet Painting | — | (925) 446 1199 | Windows, patio, painters | Concord · Contra Costa County | — | — |
| Best Countertops INC DBA Lamorinda Stone Tile | Martinez Antonio | — | (925) 584 8705 | Other | Concord · Contra Costa County | — | — |
| Best Deal Builders INC | Salvador Padilla Casillas | — | (559) 217 0150 | GC, remodel, ADU | Bethel Island · Contra Costa County | — | — |
| Best Decision Tree Service | Francisco Javier Gonzalez Gallo | — | (925) 791 1312 | Tree | Antioch · Contra Costa County | — | — |
| Best Eagles Roofing | Jaime Nicholas Nevarez | — | (510) 575 6011 | Other roofers | Oakley · Contra Costa County | — | — |
| Best Floors INC | Isaac Matthew Langskov | — | (925) 968 5069 | Other | Martinez · Contra Costa County | — | — |
| Best Home Remodeling INC | Edgardo Mejia Calderon | — | (510) 453 4845 | GC, remodel, ADU | Richmond · Contra Costa County | — | — |
| Best Homes Construction | Rajinder Singh Dhaliwal | — | (510) 367 9546 | GC, remodel, ADU | El Sobrante · Contra Costa County | — | — |
| Best Offer Glass | Best Offer Glass | — | (415) 310 6948 | Windows, patio, painters | Walnut Creek · Contra Costa County | — | — |
| Best Pavers INC DBA Best Construction | Robert Zachary Cruz | — | (510) 730 5581 | GC, remodel, ADU | Pinole · Contra Costa County | — | — |
| Best Property Management Inc. | Best Property Management Inc. | — | (925) 392-2411 | Property managers | Brentwood · Contra Costa County | — | — |
| Best Quality Tree Service | Gaytan Guzman Ronald | — | (510) 779 3008 | GC, remodel, ADU | San Pablo · Contra Costa County | — | — |
| Bestoff Windows And Construction | Sergey Leonid Oreshkin | — | (925) 457 9026 | GC, remodel, ADU | Concord · Contra Costa County | — | — |
| Bestoff Windows INC | Sergey Leonid Oreshkin | — | (925) 457 9026 | Windows, patio, painters | Concord · Contra Costa County | — | — |
| Beto Limon's Grading INC | Jose Alberto| Limon Alberto Limon | — | (925) 709 9070 | GC, remodel, ADU | Bay Point · Contra Costa County | — | — |
| Better Builders Construction | Traehone Juan Molina Banda | — | (925) 743 1126 | GC, remodel, ADU | Danville · Contra Costa County | — | — |
| Better City Tree Services INC | David Gallo | bettercity3@gmail.com | (925) 464 9010 | Tree | Martinez · Contra Costa County | — | — |
| Better Home Remodeling | Rudolf Stephens Co Van Schaik | — | (510) 909 2828 | GC, remodel, ADU | Bethel Island · Contra Costa County | — | — |
| Better Home Tiling Services | Yaroslav Hristov Yanakiev | — | (650) 576 3951 | Other | Lafayette · Contra Costa County | — | — |
| Better Rooter INC | Alejandro Silva Vazquez | — | (510) 374 6129 | Other | Richmond · Contra Costa County | — | — |
| Better Security | Better Security | info@betta-security.de | (925) 300 5041 | Electricians | Danville · Contra Costa County | — | — |
| Better Tree Care INC | Zerimar Alvarado | — | (925) 834 6438 | Other | Antioch · Contra Costa County | — | — |
| Beyond Basics Construction | Van Stewart Sutton | — | (925) 743 8138 | GC, remodel, ADU | Danville · Contra Costa County | — | — |
| Beyond Sound | Beyond Sound | — | (925) 584 1319 | Other | Brentwood · Contra Costa County | — | — |
| Bf Datacom INC | William Naman Jr Farhood | bfarhood@bfdatacom.com | (310) 710 8304 | Other | Walnut Creek · Contra Costa County | — | — |
| Bfco Construction | Chaz Ari Kussoy | — | (510) 334 7028 | GC, remodel, ADU | Pinole · Contra Costa County | — | — |
| Bg Painting INC | Byron Giovanni Santos Arreaga | info@bgpaintings.com | (510) 228 5557 | Windows, patio, painters | Richmond · Contra Costa County | — | — |
| Bhp Contracting DBA Bhp Electrical Integrations | Matthew James Pflueger | — | (925) 665 3434 | Electricians | Pittsburg · Contra Costa County | — | — |
| Bid Right Construction INC | James Loren Ii Wolfsmith | — | (510) 552 9036 | GC, remodel, ADU | Pleasant Hill · Contra Costa County | — | — |