| Unique Pools INC | Bryan Douglas Lozier | — | (925) 513 3800 | GC, remodel, ADU | Danville · Contra Costa County | — | — |
| United Constructors INC | Cash Kennerson Payne | — | (925) 487 2623 | GC, remodel, ADU | Pleasant Hill · Contra Costa County | — | — |
| United Fire And Alarm Construction INC | Jason Allen Sillman | — | (925) 987 2623 | Electricians | Alamo · Contra Costa County | — | — |
| United Plumbing Group | Etson Cardenas | info@unitedplumbinggroup.com | (925) 382 2663 | Other | Concord · Contra Costa County | — | — |
| United Services | Adrian Oene Veenbaas | — | (510) 414 8816 | GC, remodel, ADU | Pinole · Contra Costa County | — | — |
| Universal California LLC | Gareth Gibson | — | (800) 847 4784 | GC, remodel, ADU | Danville · Contra Costa County | — | — |
| Universal Construction | Julio Cesar Sanchez | — | (510) 815 0842 | GC, remodel, ADU | El Sobrante · Contra Costa County | — | — |
| Universal Painting | Universal Painting | amc@uipcl.com | (925) 262 7922 | Windows, patio, painters | Concord · Contra Costa County | — | — |
| Universal Refrigeration Services | Arceo Jose | — | (925) 978 9285 | HVAC | Antioch · Contra Costa County | — | — |
| Unlimited Builders INC | Salvador Sandoval | — | (510) 774 8700 | GC, remodel, ADU | Antioch · Contra Costa County | — | — |
| Unlimited Construction Company | Zdenek Sidney Polcar | unlimitedconstruction@mail.com | (510) 825 2784 | GC, remodel, ADU | Brentwood · Contra Costa County | — | — |
| Unlimited Property Services Incorporated | Scott Thomas Swinton | — | (510) 715 0653 | GC, remodel, ADU | Concord · Contra Costa County | — | — |
| Unpingco Electric | Peter Uson Unpingco | — | (925) 354 4257 | Electricians | Antioch · Contra Costa County | — | — |
| Unt Construction INC | Mei Xiang | %20contact@untconstruction.com | (415) 272 0650 | GC, remodel, ADU | Antioch · Contra Costa County | — | — |
| Up & Above Heating And Cooling Services | Hassem Mohammad Samara | — | (415) 910 1447 | HVAC | Pittsburg · Contra Costa County | — | — |
| Upgrade Painting | Upgrade Painting | — | (415) 754 5232 | Windows, patio, painters | Pinole · Contra Costa County | — | — |
| Upkeep Industries INC | David Stanley Jones | — | (925) 812 4646 | Electricians | Concord · Contra Costa County | — | — |
| Upmerge Construction INC | Edgar Iban Paez Castillo | — | (510) 630 0238 | GC, remodel, ADU | San Pablo · Contra Costa County | — | — |
| Urban Built Construction INC | Juan Carlos Jr Santisteban | — | (415) 740 7273 | GC, remodel, ADU | Antioch · Contra Costa County | — | — |
| Urban City Mechanical | Urban City Mechanical | — | (510) 619 6586 | HVAC | Pittsburg · Contra Costa County | — | — |
| Urban Shore Builders | Urban Shore Builders | urbanshorebuilders@comcast.net | (415) 717 9501 | GC, remodel, ADU | Point Richmond · Contra Costa County | — | — |
| Urethane Coating | Daniel Ramon Garcia | — | (408) 420 9656 | GC, remodel, ADU | Brentwood · Contra Costa County | — | — |
| Uribe Quality Construction | David Eduardo Uribe | — | (925) 687 5782 | GC, remodel, ADU | Concord · Contra Costa County | — | — |
| Us Accurate Construction & Development INC | Mohamad Seraj Farshid Ostad | — | (925) 690 7429 | GC, remodel, ADU | Lafayette · Contra Costa County | — | — |
| Us Demo And Hauling INC DBA Cal Pavers | Marcelo De Santana Lima | — | (925) 376 3050 | Other | Moraga · Contra Costa County | — | — |
| Us Imperial Construction | Jazmine Stephanie Hernandez Pascual | — | (425) 663 1351 | GC, remodel, ADU | San Pablo · Contra Costa County | — | — |
| Usa Carpet And Vinyl | Richard Ernesto Cartagena | — | (510) 235 9923 | Other | Richmond · Contra Costa County | — | — |
| Usa Pavers Corp | Carlos Alexandre Alves Vieira | info@usapavers.com | (510) 258 7216 | Other | Brentwood · Contra Costa County | — | — |
| Usa Scales INC | Roderic Charles Jr Ward | — | (925) 634 8068 | Other | Byron · Contra Costa County | — | — |
| Utopia Property Management | Walnut Creek Ca | Utopia Property Management | Walnut Creek Ca | — | (650) 410-1111 | Property managers | Walnut Creek · Contra Costa County | — | — |
| V And G Builders | V And G Builders | — | (925) 639 0892 | GC, remodel, ADU | Concord · Contra Costa County | — | — |
| V C Toland INC DBA Classic Pools | Val Conrad Toland | — | (925) 827 4700 | Pool | Concord · Contra Costa County | — | — |
| V D L Electric | Vincent Michael Fratangelo | — | (510) 719 5413 | Electricians | Pleasant Hill · Contra Costa County | — | — |
| V Development INC DBA Capital Builders | Manuel Salvator Vierra | — | (925) 634 8890 | GC, remodel, ADU | Brentwood · Contra Costa County | — | — |
| V H A Painting | V H A Painting | — | (925) 699 8607 | Windows, patio, painters | Antioch · Contra Costa County | — | — |
| V I T Plumbing & Leak Detection | Vladimir I Tsoy | — | (925) 395 3623 | Other | Concord · Contra Costa County | — | — |
| V L Plumbing | V L Plumbing | — | (510) 375 3954 | Other | Rodeo · Contra Costa County | — | — |
| V Mendoza Roofing INC | Valente G Mendoza | — | (925) 783 6265 | Other roofers | Brentwood · Contra Costa County | — | — |
| V R 5 Construction INC | Omar Elias Yanez Fletes | — | (925) 642 8423 | GC, remodel, ADU | Antioch · Contra Costa County | — | — |
| V/c's Painting | V/c's Painting | — | (510) 944 2756 | Windows, patio, painters | Richmond · Contra Costa County | — | — |