| Blackwater Construction | O'mochain Peadar | — | (415) 320 3603 | GC, remodel, ADU | Sausalito · Marin County | — | — |
| Blair Burke General Contractors INC | Jay Blair Burke | — | (415) 524 3679 | GC, remodel, ADU | San Rafael · Marin County | — | — |
| Blanco Painting | Blanco Painting | — | (415) 532 4287 | Windows, patio, painters | San Rafael · Marin County | — | — |
| Blu Dolphin Pool Service & Repair | Richard Bryan Mc Haney | — | (415) 878 4925 | Pool | Novato · Marin County | — | — |
| Blue Anchor Building Company | David Kirkpatrick Mc Morran | — | (415) 948 7267 | GC, remodel, ADU | Sausalito · Marin County | — | — |
| Blue Mountain Construction | Jeffrey Thomas Toy Wong | — | (415) 388 3883 | Electricians | Mill Valley · Marin County | — | — |
| Blue Mountain Electric | James Carl Bockhorst | info@bluemountainelectric.com | (415) 517 2066 | Electricians | Larkspur · Marin County | — | — |
| Blue Sky Bay Area LLC | Erick Rocael Alezano Diego | — | (415) 525 0892 | GC, remodel, ADU | Novato · Marin County | — | — |
| Blue Turtle Painting & Waterproofing | Blue Turtle Painting & Waterproofing | — | (415) 453 1212 | GC, remodel, ADU | San Rafael · Marin County | — | — |
| Bo Williams INC | Richard Bartlett Williams | — | (415) 246 4837 | Other | Novato · Marin County | — | — |
| Bob Ellison Woodwork INC | Robert Gregory Ellison | — | (415) 716 6472 | GC, remodel, ADU | Novato · Marin County | — | — |
| Bob Kunst Painting INC Kunst Painting | Anriette France Kunst | — | (415) 457 0100 | Windows, patio, painters | San Rafael · Marin County | — | — |
| Bob Moritz's Reliable Plumbing Service INC | Robert Wayne Moritz | — | (415) 509 4929 | Other | Novato · Marin County | — | — |
| Bob's Tree Service | Robert Brian Emrich | — | (415) 390 2711 | Tree | Mill Valley · Marin County | — | — |
| Bobzien Electric | Chris Allan Bobzien | — | (415) 531 9125 | Electricians | Sausalito · Marin County | — | — |
| Boeck & Associates Painting Company INC | Lawrence George Jr Boeck | — | (415) 491 1702 | Windows, patio, painters | San Rafael · Marin County | — | — |
| Bofill Construction INC | Bofill Diego Medeiros | diego@bofillconstruction.com | (415) 712 8747 | GC, remodel, ADU | Woodacre · Marin County | — | — |
| Bogie's Pump Systems | Suzanne Lorriane Thomas | — | (415) 884 4501 | Other | Novato · Marin County | — | — |
| Bohemian Creative Design And Building | Bohemian Creative Design And Building | — | (707) 867 6104 | GC, remodel, ADU | Tomales · Marin County | — | — |
| Bohlman | Jerome Paul Bohlman | — | (415) 847 4005 | Windows, patio, painters | San Anselmo · Marin County | — | — |
| Boiler Burner Control INC | Eugene Joseph Porter | — | (415) 250 0029 | HVAC | Tiburon · Marin County | — | — |
| Boltwest LLC | Angela Marie Bauman | boltwestbypal@gmail.com | (415) 917 0075 | Windows, patio, painters | San Rafael · Marin County | — | — |
| Bonini Construction | William Arnold Jr Bonini | — | (707) 332 5237 | GC, remodel, ADU | Tomales · Marin County | — | — |
| Booth & Little | Silvia Lucia Little | — | (415) 924 2733 | Other roofers | Greenbrae · Marin County | — | — |
| Borgo Built INC | Thelis Abreu Borgo | — | (415) 261 8001 | GC, remodel, ADU | San Anselmo · Marin County | — | — |
| Bortolussi & Watkin INC | Raul Garcia | — | (415) 453 4675 | Windows, patio, painters | San Rafael · Marin County | — | — |
| Bourke Plumbing | Bourke Plumbing | — | (415) 945 1891 | Other | Larkspur · Marin County | — | — |
| Boyce Construction | Shane Hanson Boyce | — | (415) 310 5014 | GC, remodel, ADU | Stinson Beach · Marin County | — | — |
| Boyce Electric INC | Dagan Boyce | — | (415) 244 2597 | Electricians | Stinson Beach · Marin County | — | — |
| Bradbury Cheshire Corporation | Kenneth Reid Frankel | — | (415) 453 3161 | GC, remodel, ADU | San Rafael · Marin County | — | — |
| Braintree Woodworks LLC | Mark Russell Biddle | — | (415) 419 9085 | GC, remodel, ADU | Point Reyes Station · Marin County | — | — |
| Bran Construction INC | Juan Gerardo Bran Bustamante | branconstruction11@gmail.com | (415) 497 3414 | GC, remodel, ADU | Novato · Marin County | — | — |
| Bravo Hardwood Floors INC | Jorge Octavio Gordoa | — | (415) 269 4389 | Other | San Rafael · Marin County | — | — |
| Brellin Company | Kurt Leroy Brellin | info@brellin.com | (415) 524 2294 | GC, remodel, ADU | San Rafael · Marin County | — | — |
| Brendan Hardiman Construction | Brendan Loy Hardiman | — | (415) 847 0355 | Other | Novato · Marin County | — | — |
| Brendon Lee Becker | Brendon Lee Becker | — | (415) 725 7607 | GC, remodel, ADU | Novato · Marin County | — | — |
| Brent David Construction | David Marton Brent | — | (415) 755 8096 | GC, remodel, ADU | San Rafael · Marin County | — | — |
| Brescia - Stone Painting INC | Greg Lewis Brescia | — | (415) 898 0388 | Windows, patio, painters | Novato · Marin County | — | — |
| Brett Woodburne Tile | Brett Woodburne Tile | — | (415) 491 1657 | Other | San Rafael · Marin County | — | — |
| Brian B Beard | Brian B Beard | — | (415) 453 1775 | GC, remodel, ADU | San Anselmo · Marin County | — | — |