| Blackstar Concrete | Blackstar Concrete | — | (925) 273 4871 | Other | Livermore · Alameda County | — | — |
| Blackwood Building | Blackwood Building | — | (415) 760 4955 | GC, remodel, ADU | Oakland · Alameda County | — | — |
| Blair Edsen | Blair Edsen | — | (925) 789 1234 | Other | Livermore · Alameda County | — | — |
| Blair Landscape Services INC | Randall Blair | — | (925) 250 0526 | Windows, patio, painters | Pleasanton · Alameda County | — | — |
| Blanco Development | Monte James Ii Maniz | — | (510) 457 5373 | GC, remodel, ADU | Oakland · Alameda County | — | — |
| Blandin Construction INC | Selvin Sabdiel Blandin Canales | — | (650) 281 6739 | GC, remodel, ADU | Oakland · Alameda County | — | — |
| Blank And Cables INC | Jeremy Kevin Bradley | — | (415) 648 3842 | Other | Oakland · Alameda County | — | — |
| Bleu Net INC | Douglas James Bibby | admin@bleunet.com | (510) 684 7053 | GC, remodel, ADU | Berkeley · Alameda County | — | — |
| Blinds For All People | Blinds For All People | — | (510) 414 4772 | Other | Oakland · Alameda County | — | — |
| Blinds Shades Shutters And More | Jacquelyn Christine Robinette | — | (925) 462 1207 | Other | Pleasanton · Alameda County | — | — |
| Bliss Tile | Bliss Tile | — | (415) 691 5351 | Other | Alameda · Alameda County | — | — |
| Blocka Construction INC | Brian Anthony Causey | — | (510) 657 3686 | HVAC | Pleasanton · Alameda County | — | — |
| Blown Away | Ryan John-Frederi Hartsinck | — | (510) 890 5747 | HVAC | Hayward · Alameda County | — | — |
| Blu Pipe Plumbing LLC | Richard Rath Pey | — | (510) 508 1214 | Other | Castro Valley · Alameda County | — | — |
| Blucal | Eddie Leo Bandini | — | (415) 578 4848 | GC, remodel, ADU | Oakland · Alameda County | — | — |
| Blue Bay Builder | Blue Bay Builder | — | (510) 723 4618 | GC, remodel, ADU | Hayward · Alameda County | — | — |
| Blue Bear Construction | Brian Keith Wimer | — | (925) 768 4245 | GC, remodel, ADU | San Leandro · Alameda County | — | — |
| Blue Door Electric LLC | Andrew Stead | — | (925) 768 3064 | Electricians | Oakland · Alameda County | — | — |
| Blue Electric | Maldonado Rafael | — | (510) 612 7179 | Electricians | Berkeley · Alameda County | — | — |
| Blue Electrical | Robert Darren Inez | chris@blueelectrical.com | (510) 754 4022 | Electricians | Pleasanton · Alameda County | — | — |
| Blue Line Electric | Dave Guanyu Zhu | — | (510) 220 8013 | Electricians | San Leandro · Alameda County | — | — |
| Blue Oak Builders INC | John Franklin Spraggins | — | (925) 323 3748 | GC, remodel, ADU | Pleasanton · Alameda County | — | — |
| Blue Phoenix Contracting LLC | Kimber Lane Dittmore | — | (510) 221 9087 | Other | Livermore · Alameda County | — | — |
| Blue Zone Builders INC | Mark Allan Bohon | — | (510) 332 8449 | GC, remodel, ADU | San Leandro · Alameda County | — | — |
| Bluefield Construction | Ye Chundong | — | (415) 999 8026 | GC, remodel, ADU | Hayward · Alameda County | — | — |
| Blueline Associates INC | Kenneth Matthew Larson | — | (925) 462 2200 | GC, remodel, ADU | Pleasanton · Alameda County | — | — |
| Bluestar Development Co | Edward Yuman Mak | sebastian@aldusleaf.org | (408) 667 0539 | GC, remodel, ADU | Fremont · Alameda County | — | — |
| Bluewagon Landscape & Design INC | Kevin Christopher Bates | — | (415) 740 4643 | Windows, patio, painters | Hayward · Alameda County | — | — |
| Bluewave Plumbing And Water Heaters LLC | Frank Hubert Carreon | — | (650) 922 9994 | Other | Castro Valley · Alameda County | — | — |
| Blum Construction | Mark Raymond Blum | — | (925) 456 9133 | GC, remodel, ADU | Livermore · Alameda County | — | — |
| Blvd Design Build LLC | Isaac Bliss Tanihaha | blvddesignbuild@gmail.com | (510) 217 8626 | GC, remodel, ADU | Alameda · Alameda County | — | — |
| Bo's Superior Plumbing INC | Sou Chiem Saephan | sou@bossuperiorplumbing.com | (510) 519 0601 | Other | Oakland · Alameda County | — | — |
| Bob Andre | Bob Andre | — | (209) 401 9165 | Windows, patio, painters | Livermore · Alameda County | — | — |
| Bob Bishop Builders INC | Robert Arthur Bishop | info@bobbishopbuilders.com | (925) 200 6240 | GC, remodel, ADU | Livermore · Alameda County | — | — |
| Bob Peterson Construction | Robert Ernest Peterson | — | (925) 918 2434 | GC, remodel, ADU | Dublin · Alameda County | — | — |
| Bob Smith Glass And Aluminum Co | Robert Charles Smith | — | (925) 963 4266 | Windows, patio, painters | Dublin · Alameda County | — | — |
| Bob's Iron INC | John E Muela | — | (510) 567 8983 | Other | San Leandro · Alameda County | — | — |
| Bob's Professional Painting | Bob's Professional Painting | — | (925) 577 6864 | Windows, patio, painters | Dublin · Alameda County | — | — |
| Boba Construction | Enkhsaruul Dashravdan | — | (510) 717 0456 | GC, remodel, ADU | Hayward · Alameda County | — | — |
| Boba Painting | Boba Painting | — | (510) 735 5050 | Windows, patio, painters | Oakland · Alameda County | — | — |