| Big A's Door Services | Andrew Tiaseuitafet Napoleone | — | (341) 600 9329 | Other | Hayward · Alameda County | — | — |
| Big A's Doors | Alani K Pahulu | — | (341) 600 9329 | Other | Hayward · Alameda County | — | — |
| Big Boys Construction INC | Ponce Gorgonio Franco | contact@bigboysconstruction.com | (510) 634 7092 | GC, remodel, ADU | Livermore · Alameda County | — | — |
| Big Brother Glazing | Big Brother Glazing | — | (925) 640 5243 | Windows, patio, painters | Oakland · Alameda County | — | — |
| Big Brothers Plumbing INC | Angel Noe Avila-Quezada | — | (510) 269 0299 | Other | Alameda · Alameda County | — | — |
| Big Cities Mechanical | Big Cities Mechanical | — | (510) 586 7224 | HVAC | San Leandro · Alameda County | — | — |
| Big Dawg Construction INC | Shane Brady Derdak | — | (925) 858 8930 | GC, remodel, ADU | Livermore · Alameda County | — | — |
| Big Green Tree Landscaping Company | Afuhaamango Taumoepeau Tonga | — | (650) 921 0830 | Windows, patio, painters | Hayward · Alameda County | — | — |
| Big Iron Fence & Fabrication LLC | Thomas Wayne Shelton | — | (925) 588 9709 | Other | Livermore · Alameda County | — | — |
| Big Joe California North INC | Bradley Burton Kiefus | — | (510) 785 6900 | Other | Hayward · Alameda County | — | — |
| Big Sur Framing | Big Sur Framing | bigsurframing@gmail.com | (510) 631 6449 | Other | Berkeley · Alameda County | — | — |
| Big Voodoo Daddy Construction | Mark Christopher Przybus | — | (510) 783 3343 | GC, remodel, ADU | Hayward · Alameda County | — | — |
| Big World Electric Company | Zheng Tao | — | (510) 406 9988 | Electricians | Castro Valley · Alameda County | — | — |
| Bigelow's Concrete | Bigelow's Concrete | — | (925) 606 4311 | Other | Livermore · Alameda County | — | — |
| Bigge Crane & Rigging Co | Christopher Allan Walker | — | (510) 638 8100 | Other | San Leandro · Alameda County | — | — |
| Bigham Taylor Roofing Corporation | Stephen Guy Yocham | — | (510) 886 0197 | Other roofers | Hayward · Alameda County | — | — |
| Bilga Construction INC | Singh Harpal | — | (510) 755 0048 | GC, remodel, ADU | Fremont · Alameda County | — | — |
| Bill Castellon Landscape INC | William Anton Castellon | — | (510) 910 5935 | Windows, patio, painters | Oakland · Alameda County | — | — |
| Bill Essig Builders Services | William Holland Iii Essig | — | (510) 418 6798 | GC, remodel, ADU | Oakland · Alameda County | — | — |
| Bill Gibbons | Bill Gibbons | — | (925) 876 0875 | GC, remodel, ADU | Livermore · Alameda County | — | — |
| Bill Siem Construction | Bill Charles Siem | — | (510) 735 1832 | GC, remodel, ADU | Castro Valley · Alameda County | — | — |
| Bill Stohlman | Bill Stohlman | — | (510) 306 6424 | GC, remodel, ADU | Berkeley · Alameda County | — | — |
| Billys General Construction | Bill Nguyen | — | (510) 213 2353 | GC, remodel, ADU | Oakland · Alameda County | — | — |
| Bilt Rite INC | Lee Min-ho | — | (510) 894 2798 | Electricians | Newark · Alameda County | — | — |
| Bin & J W INC | Michael Wong | — | (510) 717 2579 | GC, remodel, ADU | San Leandro · Alameda County | — | — |
| Bin Pham Landscaping | Sang Thanh Hoang | — | (510) 902 8382 | Windows, patio, painters | Hayward · Alameda County | — | — |
| Bingo Builders | Kwok Leung Chan | — | (650) 866 9996 | GC, remodel, ADU | Castro Valley · Alameda County | — | — |
| Bioscapes INC | Mary Elizabeth Sayers | — | (408) 410 4502 | Tree | Newark · Alameda County | — | — |
| Biotics Landscape Management INC | Brenda Lee Condon | — | (925) 485 4837 | Windows, patio, painters | Pleasanton · Alameda County | — | — |
| Bird Dog Build Co LLC | Christian Jean Rousset | — | (415) 640 2114 | GC, remodel, ADU | Oakland · Alameda County | — | — |
| Bisimwa Electric | Kamanyola Claude Bisimwa | — | (650) 575 4730 | Electricians | Castro Valley · Alameda County | — | — |
| Biying Liu | Biying Liu | — | (510) 303 2166 | GC, remodel, ADU | Fremont · Alameda County | — | — |
| Bjork Construction Company INC | Jessica Nicole| Bjork Jessica Nicole Madrigal | — | (510) 257 9788 | GC, remodel, ADU | Fremont · Alameda County | — | — |
| Bkn Construction INC | Bao Van Dang | bknconstructioninc@gmail.com | (510) 919 1085 | GC, remodel, ADU | Hayward · Alameda County | — | — |
| Black Creek Builders INC | Travis Danforth Wirt | — | (800) 737 7113 | Electricians | Oakland · Alameda County | — | — |
| Black Diamond Paving LLC | Christopher Angel Soria | contact@blackdiamondpaving.com | (510) 770 1150 | Other | Hayward · Alameda County | — | — |
| Black Galaxy Tile & Marble | Black Galaxy Tile & Marble | — | (510) 604 6862 | Other | Oakland · Alameda County | — | — |
| Black Lava Asphalt INC | Jorge Luis Saldana | — | (510) 579 1427 | Other | San Leandro · Alameda County | — | — |
| Black Mountain Development | Jeffrey Michael Woods | — | (925) 520 0001 | GC, remodel, ADU | Pleasanton · Alameda County | — | — |
| Black Oak Construction | Jason Anthony Smith | — | (510) 455 0819 | GC, remodel, ADU | Oakland · Alameda County | — | — |