| Barndt's Welding INC | Larry Raymond Barndt | — | (707) 585 3114 | Other | Cotati · Sonoma County | — | — |
| Barnhart Plumbing | Barnhart Plumbing | — | (415) 246 5853 | Other | Petaluma · Sonoma County | — | — |
| Barone Drywall | Barone Drywall | — | (415) 819 9255 | Other | Petaluma · Sonoma County | — | — |
| Barragan Tree Service INC | Erick Barragan | astigma@astigmatic.com | (707) 338 8606 | Tree | Boyes Hot Springs · Sonoma County | — | — |
| Barrera Construction | Rodrigo Benyosept Barrera Lara | — | (707) 843 9469 | GC, remodel, ADU | Boyes Hot Springs · Sonoma County | — | — |
| Barrios Electric | Jose Juan Barrios Morales | — | (415) 225 0362 | Electricians | Petaluma · Sonoma County | — | — |
| Barron Construction | Charles Michael Barron | charlie@barronconstruction.com | (707) 490 9274 | GC, remodel, ADU | Rohnert Park · Sonoma County | — | — |
| Barron Plumbing | Barron Plumbing | — | (707) 545 4979 | Other | Santa Rosa · Sonoma County | — | — |
| Barry Construction INC | Mark William Barry | — | (707) 775 8816 | GC, remodel, ADU | Petaluma · Sonoma County | — | — |
| Barry Mullis Construction | Barry Joseph Mullis | barry@barrymullisconstruction.com | (415) 279 0079 | GC, remodel, ADU | Petaluma · Sonoma County | — | — |
| Bartkus Remodel | Bartkus Remodel | — | (707) 477 8601 | GC, remodel, ADU | Petaluma · Sonoma County | — | — |
| Bartlett Tree Experts | Bartlett Tree Experts | — | (707) 935-3220 | Tree | Sonoma · Sonoma County | — | — |
| Barwood Enterprises INC | John Joseph Hazlewood | — | (707) 484 3083 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |
| Basic Prune Incorporated DBA Hagstrom And Sons Tree Service | Kevin Richard Hagstrom | — | (707) 579 4374 | Tree | Santa Rosa · Sonoma County | — | — |
| Bass Electric | Julian Charles Bass | — | (707) 806 9976 | Electricians | Santa Rosa · Sonoma County | — | — |
| Batchelder C L General Engineering INC | Clifton Leonard Batchelder | — | (707) 494 1015 | Other | Forestville · Sonoma County | — | — |
| Bathe' Builders | Bathe' Builders | — | (415) 858 9303 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |
| Bavarian Timberworks | Bavarian Timberworks | — | (707) 888 8463 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |
| Baxter Construction | Gregory Murray Baxter | — | (707) 738 5249 | GC, remodel, ADU | Sonoma · Sonoma County | — | — |
| Bay Area Home Solutions | Bay Area Home Solutions | — | (415) 706 4396 | GC, remodel, ADU | Petaluma · Sonoma County | — | — |
| Bay Area Mechanical And Engineering INC | Jack Berzin | — | (707) 540 5983 | HVAC | Penngrove · Sonoma County | — | — |
| Bay Area Millworks INC | Robin Stuart Slimmer | — | (707) 332 3200 | GC, remodel, ADU | Occidental · Sonoma County | — | — |
| Bay Area Water Conditioning | Bay Area Water Conditioning | — | (707) 584 5508 | Other | Santa Rosa · Sonoma County | — | — |
| Bay Cities Fire Protection INC | John Alfred Hess | — | (707) 579 8694 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |
| Bay Cities Fire Suppression INC | John Alfred Hess | — | (707) 978 2598 | Other | Windsor · Sonoma County | — | — |
| Bay Side Plumbing | Bay Side Plumbing | — | (415) 985 5901 | Other | Petaluma · Sonoma County | — | — |
| Bay To Bay Builders INC | Kevin Duane Simmonds | — | (707) 239 2084 | GC, remodel, ADU | Penngrove · Sonoma County | — | — |
| Bay View Builder | Bay View Builder | — | (707) 477 7294 | GC, remodel, ADU | Sebastopol · Sonoma County | — | — |
| Bay View Paintworks | Bay View Paintworks | — | (707) 303 5799 | Windows, patio, painters | Rohnert Park · Sonoma County | — | — |
| Bay West Construction | Joe Nicholaos Sarantis | — | (415) 577 1320 | GC, remodel, ADU | Rohnert Park · Sonoma County | — | — |
| Baycat6 LLC | Raphael Amato Sonstein | — | (847) 736 8567 | Other | Santa Rosa · Sonoma County | — | — |
| Bayly Builds | Christopher Ottem Bayly | baylychris@yahoo.com | (707) 360 7298 | GC, remodel, ADU | Healdsburg · Sonoma County | — | — |
| Bayside Stripe & Seal INC | Ramy Anthony Mughannam | — | (707) 765 2871 | Windows, patio, painters | Petaluma · Sonoma County | — | — |
| Bayterra Landscapes INC | Stephen Matthew Rochlin | — | (707) 363 9719 | Windows, patio, painters | Sonoma · Sonoma County | — | — |
| Bdk Septic Service | Jason Alexander Karnes | bdksepticservice@yahoo.com | (707) 570 2270 | Other | Santa Rosa · Sonoma County | — | — |
| Beacon Fire Protection | Beacon Fire Protection | — | (707) 494 6530 | Other | Sebastopol · Sonoma County | — | — |
| Beake Bros Electric | Chetel William | — | (707) 888 7365 | Electricians | Sebastopol · Sonoma County | — | — |
| Beale Built | Beale Built | — | (707) 357 4482 | GC, remodel, ADU | Petaluma · Sonoma County | — | — |
| Beale Construction INC | Michael Paul Jr Beale | — | (707) 696 0439 | GC, remodel, ADU | Cotati · Sonoma County | — | — |
| Bear State Construction | Curtis Leon Clemmer | — | (707) 332 9091 | GC, remodel, ADU | Sebastopol · Sonoma County | — | — |