| Red House Construction | Rafael Adolfo Martinez | — | (415) 760 3264 | GC, remodel, ADU | Antioch · Contra Costa County | — | — |
| Red Rooster Construction LLC | Donald Patrick Bloxsom | — | (925) 494 8706 | GC, remodel, ADU | Walnut Creek · Contra Costa County | — | — |
| Red White & Blue Construction INC | Hernandez Omar Romero | — | (415) 513 2944 | GC, remodel, ADU | Concord · Contra Costa County | — | — |
| Reddi-rooter | Daniel Dean Thompson | — | (925) 676 6722 | Other | Concord · Contra Costa County | — | — |
| Redeemed Construction INC | Martin Prilla Chandrawinata | — | (415) 794 3926 | GC, remodel, ADU | Concord · Contra Costa County | — | — |
| Redline Integrated Systems INC | Javier Alcalde | — | (925) 322 7920 | Electricians | Brentwood · Contra Costa County | — | — |
| Redo House LLC | Oscar M Merino | — | (510) 778 2207 | GC, remodel, ADU | Martinez · Contra Costa County | — | — |
| Redoak Construction | Rudolph Valentino Sandoval | impallari@gmail.com | (510) 563 9985 | GC, remodel, ADU | El Sobrante · Contra Costa County | — | — |
| Redwood Electric | Param Jothi | — | (925) 360 3167 | Electricians | Concord · Contra Costa County | — | — |
| Redwood Landscaping And Maintenance Company | Stanley Anthony Ramella | — | (925) 451 8270 | Windows, patio, painters | Martinez · Contra Costa County | — | — |
| Reedco Building Innovations INC | Robert Harold Reed | — | (925) 595 6984 | GC, remodel, ADU | Martinez · Contra Costa County | — | — |
| Refit Construction | Painting Schaefer's | — | (925) 260 6065 | GC, remodel, ADU | Clayton · Contra Costa County | — | — |
| Refresh - Paint INC | Ryan Thomas Burns | — | (510) 334 8692 | Windows, patio, painters | El Sobrante · Contra Costa County | — | — |
| Refresh Painting | Guilherme Oliveira Silva Costa | nate@refresh-painting.com | (510) 210 7507 | Windows, patio, painters | Richmond · Contra Costa County | — | — |
| Regal Road | Regal Road | — | (510) 502 7527 | GC, remodel, ADU | Lafayette · Contra Costa County | — | — |
| Reginato Construction | Gregory Michael Reginato | — | (510) 325 0382 | GC, remodel, ADU | El Sobrante · Contra Costa County | — | — |
| Reica Construction INC | Richard Wayne Muench | — | (925) 684 9117 | GC, remodel, ADU | Oakley · Contra Costa County | — | — |
| Reimagine Construction | Gabriel Juan Gomez | — | (510) 717 2285 | GC, remodel, ADU | Danville · Contra Costa County | — | — |
| Reinholdt Engineering Construction | Darin James Reinholdt | — | (925) 689 8406 | Other | Concord · Contra Costa County | — | — |
| Reis & Sons Construction LLC | Onaje Timothy Boone | — | (510) 426 3117 | GC, remodel, ADU | El Sobrante · Contra Costa County | — | — |
| Rel Construction | Ryan Evan Lotman | — | (925) 818 7810 | GC, remodel, ADU | Martinez · Contra Costa County | — | — |
| Reliable Garage Doors Of Contra Costa County | Richard James Anderson | — | (925) 272 8477 | Other | Concord · Contra Costa County | — | — |
| Reliable Plumbing | Reliable Plumbing | — | (925) 759 0736 | Other | Oakley · Contra Costa County | — | — |
| Reliable Plumbing Expert LLC | Carlos Adolfo Salcedo | — | (925) 316 5037 | Other | Pleasant Hill · Contra Costa County | — | — |
| Reliable Water Heaters | Reliable Water Heaters | contact@reliablewaterheaters.com | (925) 812 4601 | Other | Antioch · Contra Costa County | — | — |
| Reliez Valley Builders INC | Christopher Robert Wright | — | (925) 932 8228 | GC, remodel, ADU | Lafayette · Contra Costa County | — | — |
| Remcon INC | Leif Howard Rohrbach | — | (925) 288 0790 | GC, remodel, ADU | Concord · Contra Costa County | — | — |
| Remnant Electrical INC | Thlang Vannak | — | (510) 919 3439 | Electricians | Antioch · Contra Costa County | — | — |
| Remodel Pro | Remodel Pro | — | (925) 708 0131 | GC, remodel, ADU | Clayton · Contra Costa County | — | — |
| Remodelchief | Farhad Hojatoleslami | — | (510) 386 1072 | GC, remodel, ADU | Pleasant Hill · Contra Costa County | — | — |
| Remodeling For You | Remodeling For You | — | (925) 595 9664 | GC, remodel, ADU | Concord · Contra Costa County | — | — |
| Remodeling Masters INC | Plamen Ivanov Feyziev | — | (925) 943 7117 | GC, remodel, ADU | Walnut Creek · Contra Costa County | — | — |
| Rennova Pro INC | Melendez Israel Orantes | info@rennovapro.com | (510) 942 5158 | GC, remodel, ADU | San Pablo · Contra Costa County | — | — |
| Repair -a - Medic | Repair -a - Medic | — | (925) 200 5109 | GC, remodel, ADU | Danville · Contra Costa County | — | — |
| Rescue Electric Corporation | Thomas Zachary Pauline | — | (925) 481 2495 | Electricians | Antioch · Contra Costa County | — | — |
| Residential Design Solutions INC | Wahid Bissada | — | (925) 989 1506 | GC, remodel, ADU | Danville · Contra Costa County | — | — |
| Resilient Fencing INC | Tiberio Vasquez | admin@resilientfencing.com | (925) 698 1840 | Other | Bay Point · Contra Costa County | — | — |
| Resurrected Gardens | Resurrected Gardens | — | (925) 698 2607 | Windows, patio, painters | Martinez · Contra Costa County | — | — |
| Reuben Borg Fence | Reuben Borg Fence | info@rbfence.com | (925) 931 0570 | GC, remodel, ADU | San Ramon · Contra Costa County | — | — |
| Reva Murphy Associates INC | Reva Lorene Murphy | — | (925) 570 3520 | Other roofers | San Ramon · Contra Costa County | — | — |