| Want Green Gardens | Melissa Marie Wilson | hello@wantgreengardens.com | (415) 465 0240 | GC, remodel, ADU | Mill Valley · Marin County | — | — |
| Warne Renovation INC | Justin Matthew Warne | info@warnerenovation.com | (415) 964 7700 | GC, remodel, ADU | Novato · Marin County | — | — |
| Warren Security Systems INC | Warren Vance Iii Glass | information@warrensecurity.com | (415) 456 7034 | Electricians | San Rafael · Marin County | — | — |
| Water Champions LLC DBA Water Champions Construction | Jay Blair Burke | — | (833) 392 8372 | GC, remodel, ADU | Fairfax · Marin County | — | — |
| Water Mold Fire Restoration INC | Sophinos John | — | (415) 289 0733 | GC, remodel, ADU | San Rafael · Marin County | — | — |
| Waterman Tile And Stone Works | Waterman Tile And Stone Works | — | (760) 703 5148 | Other | Bolinas · Marin County | — | — |
| Watson Plumbing | Watson Plumbing | — | (415) 302 1004 | Other | San Rafael · Marin County | — | — |
| Watters Construction | James William Watters | — | (925) 324 3685 | GC, remodel, ADU | Inverness · Marin County | — | — |
| Wave Hill Professional Landscaping | Wave Hill Professional Landscaping | — | (415) 408 8301 | Windows, patio, painters | Fairfax · Marin County | — | — |
| Wb Building Solutions LLC | Russell Rocky Catelli | — | (415) 794 6003 | GC, remodel, ADU | San Rafael · Marin County | — | — |
| Weatherill And Associates INC | Sean Brian Weatherill | — | (415) 994 4302 | Windows, patio, painters | Sausalito · Marin County | — | — |
| Wedge Roofing | Wedge Roofing | info@wedgeroofing.com | (888) 763-7663 | Other roofers | Marin · Marin County | — | — |
| Weh General Builders INC | Nelson Vladimir Herrera | — | (415) 259 9837 | GC, remodel, ADU | San Rafael · Marin County | — | — |
| Weis & Son | Weis & Son | — | (415) 815 8651 | GC, remodel, ADU | Mill Valley · Marin County | — | — |
| Werner's General Contractor INC | Werner Frisly De Leon Gramajo | — | (415) 760 0074 | GC, remodel, ADU | Novato · Marin County | — | — |
| Wesco Screen Company INC | James Robert Hislop | info@wescoscreen.com | (415) 453 8722 | Other | San Rafael · Marin County | — | — |
| West Coast Builders And Associates INC | Pablo Eduardo Silva | — | (415) 246 4357 | GC, remodel, ADU | Novato · Marin County | — | — |
| West Coast Creative Construction INC | Richard Everard Wodehouse | — | (415) 944 0278 | GC, remodel, ADU | Tiburon · Marin County | — | — |
| West Coast Project Management INC | Richard Everard Wodehouse | — | (415) 944 0278 | GC, remodel, ADU | Tiburon · Marin County | — | — |
| West Coastal Builders | West Coastal Builders | — | (628) 233 4108 | GC, remodel, ADU | San Rafael · Marin County | — | — |
| West Cork Plumbing INC | O'donabhain Derek | — | (415) 845 3870 | Other | Novato · Marin County | — | — |
| West Marin Builders Alliance | Stephen Matthew Horvat | — | (415) 246 8981 | GC, remodel, ADU | Point Reyes Station · Marin County | — | — |
| West Marin Welding INC | Dennis Edward A Jr Irish | irishwelding@gmail.com | (415) 497 1909 | Other | Woodacre · Marin County | — | — |
| West Peak Builders INC | Michael Eric Moller | — | (415) 991 9547 | GC, remodel, ADU | Fairfax · Marin County | — | — |
| Western Regional Painting | Western Regional Painting | — | (415) 608 9717 | Windows, patio, painters | San Rafael · Marin County | — | — |
| Western Time Electric | Harro Jeffrey Clifton | — | (415) 299 1284 | Electricians | Novato · Marin County | — | — |
| Westport Construction | Mark Michael Boylan | — | (415) 846 4086 | GC, remodel, ADU | Lagunitas · Marin County | — | — |
| Westward Builders LLC | Richard Walton Iii Williams | — | (415) 459 2130 | GC, remodel, ADU | San Rafael · Marin County | — | — |
| Westwind Construction Management INC | David Andrew Johnston | — | (415) 312 8084 | GC, remodel, ADU | San Anselmo · Marin County | — | — |
| Whitcomb Construction | Jeff Allan Whitcomb | — | (415) 382 0687 | GC, remodel, ADU | Novato · Marin County | — | — |
| White Horse Builders | White Horse Builders | — | (415) 924 8718 | GC, remodel, ADU | Corte Madera · Marin County | — | — |
| Wick Brothers Construction | Bruce Eldon Wick | — | (415) 488 9581 | GC, remodel, ADU | Woodacre · Marin County | — | — |
| Wilderose Landscapes | Elliot Lawrence Kaplan | — | (510) 689 1870 | Windows, patio, painters | Fairfax · Marin County | — | — |
| Wilkerson Electric | Erinn Thomas Wilkerson | wilkersonelectricservices@gmail.com | (513) 869-9465 | Electricians | Fairfax · Marin County | — | — |
| Wilkinson Design & Construction INC | Pavil Nicholas Wilkinson | — | (415) 785 7961 | GC, remodel, ADU | San Rafael · Marin County | — | — |
| Willemsgarden | Wilhelm Jakob De Vries | — | (415) 713 9693 | Windows, patio, painters | Mill Valley · Marin County | — | — |
| William Brent Redding | William Brent Redding | — | (415) 238 6143 | GC, remodel, ADU | San Anselmo · Marin County | — | — |
| William Carmassi | William Carmassi | — | (415) 518 0915 | Windows, patio, painters | Fairfax · Marin County | — | — |
| William Clark Smith Construction | William Clark Smith | — | (415) 640 3856 | GC, remodel, ADU | Novato · Marin County | — | — |
| William Gotelli Plumbing INC DBA Gotelli Plumbing Company | Laura Lee Pokovich | — | (415) 457 1145 | Other | San Rafael · Marin County | — | — |