| Blood Sweat & Rebar INC | Michael Eugene Hulsey | — | (925) 687 8246 | Other | Martinez · Contra Costa County | — | — |
| Blue Bay Drywall | Blue Bay Drywall | bluebaydrywall@gmail.com | (510) 691 3570 | Other | Richmond · Contra Costa County | — | — |
| Blue Beret Painting | Blue Beret Painting | — | (857) 201 6052 | Windows, patio, painters | San Pablo · Contra Costa County | — | — |
| Blue Castle Construction | Barboza Christopher | info@bluecastleconstruction.com | (408) 592 1335 | GC, remodel, ADU | Danville · Contra Costa County | — | — |
| Blue Champagne Pools INC | Wayne Stuart Jr Olson | — | (925) 809 0486 | Pool | Brentwood · Contra Costa County | — | — |
| Blue Dimensions Construction INC | Damian Guillermo | — | (925) 584 5971 | GC, remodel, ADU | Bay Point · Contra Costa County | — | — |
| Blue Dog Construction & Renovation | Andrew James Gregor | — | (510) 260 6058 | GC, remodel, ADU | Lafayette · Contra Costa County | — | — |
| Blue Drawings Construction INC | Ernesto Sr Perez Bazan | — | (925) 522 9973 | GC, remodel, ADU | Knightsen · Contra Costa County | — | — |
| Blue Flame Crew West LLC | Randy Clark Masukawa | — | (630) 225 4286 | Other | Danville · Contra Costa County | — | — |
| Blue Hawk Painting | Blue Hawk Painting | — | (925) 989 7604 | Windows, patio, painters | San Ramon · Contra Costa County | — | — |
| Blue Heron Builder | Blue Heron Builder | — | (510) 329 1519 | GC, remodel, ADU | Richmond · Contra Costa County | — | — |
| Blue Horizon Pools | Heidi Elizabeth Bennett | — | (925) 207 8810 | Pool | Martinez · Contra Costa County | — | — |
| Blue Jade Construction INC | Tayfun Baris Tufekcioglu | — | (408) 675 5550 | GC, remodel, ADU | Discovery Bay · Contra Costa County | — | — |
| Blue Jay Construction | John Steven Nicklas | — | (510) 788 0067 | GC, remodel, ADU | Pinole · Contra Costa County | — | — |
| Blue Landscape & Design Corp | Melvin Edilmer Ixcoy Sontay | — | (510) 660 5864 | Windows, patio, painters | Richmond · Contra Costa County | — | — |
| Blue Line | Blue Line | — | (925) 754-6100 | Property managers | Antioch · Contra Costa County | — | — |
| Blue Mountain Hardwood Floors | Blue Mountain Hardwood Floors | — | (510) 689 8101 | Other | Antioch · Contra Costa County | — | — |
| Blue Reef Homes INC | Barbara Anita Rosenthal | tony@bluereefhomes.com | (209) 345 4067 | GC, remodel, ADU | Brentwood · Contra Costa County | — | — |
| Blue Ridge Cabinets INC | Kyle James Foster | kyle@blueridgecabinets.com | (925) 798 4899 | Other | Concord · Contra Costa County | — | — |
| Blue Rock Home INC | Matthew Adam Shedd | — | (925) 335 6770 | GC, remodel, ADU | Moraga · Contra Costa County | — | — |
| Blue Star Heating & Air Conditioning INC | Jeffrey Boris Scalier | — | (925) 584 2428 | HVAC | Antioch · Contra Costa County | — | — |
| Blue Wave Pools | Blue Wave Pools | — | (925) 818 1662 | Pool | Concord · Contra Costa County | — | — |
| Blue Wrench Plumbing INC | Malherbe Nico | — | (925) 222 5941 | Other | Bay Point · Contra Costa County | — | — |
| Blueline Engineering INC | Jeffrey Richard Barrett | — | (925) 287 0102 | GC, remodel, ADU | Concord · Contra Costa County | — | — |
| Blueprint & Beyond | Blueprint & Beyond | — | (516) 580 6804 | Other | San Ramon · Contra Costa County | — | — |
| Bluerock Pools | Estrella Ramos Garcia | — | (925) 382 6042 | Pool | Pittsburg · Contra Costa County | — | — |
| Bluesky Concrete INC | Sione Tonga Finau | — | (925) 489 7751 | Other | Antioch · Contra Costa County | — | — |
| Bluhon | Bluhon Peter | — | (510) 841 3255 | Windows, patio, painters | Kensington · Contra Costa County | — | — |
| Bmc Co INC | Miguel Angel Martinez Cazares | — | (510) 479 4594 | GC, remodel, ADU | Concord · Contra Costa County | — | — |
| Bmc Electric | Perales Oscar Diaz | bmcelectric1900@hotmail.com | (415) 756 5166 | Electricians | San Pablo · Contra Costa County | — | — |
| Bmg Remodeling Corporation | Navarro Jesse Lopez | — | (925) 334 8484 | GC, remodel, ADU | Walnut Creek · Contra Costa County | — | — |
| Bmt 13 Construction INC | Cao Binh Huynh | — | (925) 487 3710 | GC, remodel, ADU | San Ramon · Contra Costa County | — | — |
| Bn Construction | Bona Nkosi Nsiala | impallari@gmail.com | (925) 497 9802 | GC, remodel, ADU | Brentwood · Contra Costa County | — | — |
| Bob Jimenez Painting | Bob Jimenez Painting | — | (925) 323 3993 | Windows, patio, painters | Antioch · Contra Costa County | — | — |
| Bob's Red Truck Construction Services | Bob Adriaan Brouwers | — | (925) 473 9525 | GC, remodel, ADU | Pittsburg · Contra Costa County | — | — |
| Bocanegra Construction | Bocanegra Martin | — | (510) 455 0914 | GC, remodel, ADU | El Cerrito · Contra Costa County | — | — |
| Bocce Builders Of America | Barrett Philip Park | — | (925) 932 4108 | Other | Martinez · Contra Costa County | — | — |
| Bocek - Compaglia | Jeffrey Alan Bocek | — | (925) 286 8603 | GC, remodel, ADU | Walnut Creek · Contra Costa County | — | — |
| Bock Electric LLC | Garrett Keoni Bock | — | (209) 712 8207 | Electricians | Danville · Contra Costa County | — | — |
| Boddy Construction | Martin James Boddy | — | (408) 891 4144 | GC, remodel, ADU | Discovery Bay · Contra Costa County | — | — |