| Bailey Windows & Doors INC | Avichai Hazan | — | (770) 778 7715 | GC, remodel, ADU | Walnut Creek · Contra Costa County | — | — |
| Bailey's Roofing | Nicholas Guy Bailey | — | (925) 334 0180 | Other roofers | Brentwood · Contra Costa County | — | — |
| Bailey's Window & Final Clean | Bailey's Window & Final Clean | — | (925) 595 1616 | Other | Concord · Contra Costa County | — | — |
| Baillie Communications INC | Steven Alexander Baillie | — | (925) 984 3657 | Other | Danville · Contra Costa County | — | — |
| Baird Construction | Joshua Lee Baird | — | (925) 400 8003 | GC, remodel, ADU | San Ramon · Contra Costa County | — | — |
| Baja Construction Co INC | Robert Jay Hayworth | — | (925) 286 9334 | GC, remodel, ADU | Martinez · Contra Costa County | — | — |
| Baja Plumbers | Baja Plumbers | — | (925) 776 7642 | Other | Antioch · Contra Costa County | — | — |
| Balanz INC | Dora Kuen Sheung Siu | — | (510) 529 5261 | GC, remodel, ADU | Orinda · Contra Costa County | — | — |
| Baldo Ramirez Landscaping | Baldo Ramirez Landscaping | info@ndiscovered.com | (415) 845 1151 | Windows, patio, painters | Richmond · Contra Costa County | — | — |
| Balducci Builders | Balducci Builders | — | (415) 525 2802 | GC, remodel, ADU | Point Richmond · Contra Costa County | — | — |
| Baldwin Construction LLC | Brian Dillon Baldwin | — | (925) 787 5228 | GC, remodel, ADU | Martinez · Contra Costa County | — | — |
| Baldwin Refrigeration LLC | Elias Brook Baldwin | — | (925) 395 9703 | HVAC | Danville · Contra Costa County | — | — |
| Baliel Enterprises | Randal Joseph Fontes | — | (925) 354 5300 | GC, remodel, ADU | Brentwood · Contra Costa County | — | — |
| Balke Construction | Todd Frederick Balke | — | (925) 584 0850 | GC, remodel, ADU | Oakley · Contra Costa County | — | — |
| Ballentine Construction Services | Nicholas John Ballentine | — | (925) 759 9865 | GC, remodel, ADU | Martinez · Contra Costa County | — | — |
| Baltodano's Drywall And Painting | Baltodano's Drywall And Painting | — | (925) 759 3994 | Windows, patio, painters | Oakley · Contra Costa County | — | — |
| Baltodano's Painting | Baltodano's Painting | — | (925) 759 3994 | Windows, patio, painters | Oakley · Contra Costa County | — | — |
| Bam Construction And Development INC | Zamani Mehran | — | (925) 497 3593 | GC, remodel, ADU | Concord · Contra Costa County | — | — |
| Bama Builders INC | Jose Antonio Madriz | — | (510) 685 9076 | GC, remodel, ADU | Richmond · Contra Costa County | — | — |
| Banister Electrical Incorporated | Daniel Thomas Pauline | — | (925) 778 7801 | Electricians | Antioch · Contra Costa County | — | — |
| Banks Communications Corp | Gregory A Banks | — | (925) 783 0003 | Other | Antioch · Contra Costa County | — | — |
| Banner Masonry INC | Linnane Michael | — | (650) 766 3641 | Other | Martinez · Contra Costa County | — | — |
| Bap Art & Desing Flooring And Carpet Covering | Bruss Jossef Aguirre Paucar | — | (925) 447 7235 | Other | Antioch · Contra Costa County | — | — |
| Barajas Pro Tiling INC | Victor Manuel Barajas Perez | bprotiling@gmail.com | (925) 529 2880 | Other | Oakley · Contra Costa County | — | — |
| Barale Builders INC | Joseph Antonio Barale | — | (925) 324 4520 | GC, remodel, ADU | Alamo · Contra Costa County | — | — |
| Barberio HVAC | Barberio HVAC | — | (925) 338 5611 | HVAC | Pleasant Hill · Contra Costa County | — | — |
| Barbour Painting LLC | Aaron Leslie Barbour | aaron@barbourpainting.com | (925) 324 7838 | Windows, patio, painters | Concord · Contra Costa County | — | — |
| Barcode Construction | Donnie Lee Davis | — | (925) 303 8712 | Other | Bethel Island · Contra Costa County | — | — |
| Bargons Custom Flooring | Bargons Custom Flooring | — | (925) 550 2714 | Other | Oakley · Contra Costa County | — | — |
| Barkasy | Frank Douglas Barkasy | — | (925) 708 4696 | Other | Concord · Contra Costa County | — | — |
| Barnes & Company | Mark Edward Barnes | hello@barnes.com | (925) 372 7026 | GC, remodel, ADU | Martinez · Contra Costa County | — | — |
| Barnett Glass Company LLC | Jesse Lee Barnett | — | (650) 834 0856 | Windows, patio, painters | Brentwood · Contra Costa County | — | — |
| Baron's Construction | Juan Pedro Baron | — | (510) 421 2614 | GC, remodel, ADU | Antioch · Contra Costa County | — | — |
| Barragan Builders Enterprises LLC | Kelly Yolanda Barragan | — | (510) 409 6132 | GC, remodel, ADU | El Cerrito · Contra Costa County | — | — |
| Barrera Construction | Barrera Arrendondo Roberto | — | (925) 325 3694 | GC, remodel, ADU | Concord · Contra Costa County | — | — |
| Barron Restoration INC | Robert Barron Mosteller | micah@micahrich.com | (925) 407 6747 | GC, remodel, ADU | Danville · Contra Costa County | — | — |
| Barsell Construction INC | John Edward Barsell | john@barsellconstruction.com | (925) 260 4331 | GC, remodel, ADU | Alamo · Contra Costa County | — | — |
| Barsell Electrical Services | Hunter Allan Barsell | — | (925) 765 8176 | Electricians | Alamo · Contra Costa County | — | — |
| Basek Electric | Artur Michal Basek | — | (925) 435 8300 | Electricians | San Ramon · Contra Costa County | — | — |
| Bassing Painting INC | Mario Noe Cubas | — | (510) 235 5551 | Windows, patio, painters | Richmond · Contra Costa County | — | — |