| Jari Construction INC | Montoya Patricia Rodriguez | info@jariconstruction.com | (510) 978 0860 | GC, remodel, ADU | Richmond · Contra Costa County | — | — |
| Jarquin Painting | Jarquin Painting | info@jarquinpainting.com | (925) 354 6870 | Windows, patio, painters | Antioch · Contra Costa County | — | — |
| Jason Gammill | Jason Gammill | — | (510) 631 2131 | Other | Point Richmond · Contra Costa County | — | — |
| Jason Mc Dermott Construction | Jason Andrew Mc Dermott | — | (510) 289 0505 | GC, remodel, ADU | Crockett · Contra Costa County | — | — |
| Jasz Co INC | Jerry D| Jd Smith | — | (510) 337 4417 | Electricians | Richmond · Contra Costa County | — | — |
| Jaws Construction INC | Jaime Javier Flores Hernandez | — | (650) 417 5928 | GC, remodel, ADU | Byron · Contra Costa County | — | — |
| Jay W Wyant Co INC | Christian Jay Wyant | — | (209) 321 7111 | Other | Byron · Contra Costa County | — | — |
| Jay's Handyman Service LLC | Jason Wayne Williams | — | (510) 366 8268 | GC, remodel, ADU | Bay Point · Contra Costa County | — | — |
| Jayco Constructors INC | Jaime Gonzalez Gutierrez | — | (415) 760 5921 | GC, remodel, ADU | Walnut Creek · Contra Costa County | — | — |
| Jayme R Zemansky | Jayme R Zemansky | — | (510) 233 7233 | GC, remodel, ADU | Richmond · Contra Costa County | — | — |
| Jb & Filo's Landscaping | Filogonio Maldonado Chavez | — | (925) 383 8671 | Windows, patio, painters | San Ramon · Contra Costa County | — | — |
| Jb Builder | Jb Builder | — | (408) 582 2543 | GC, remodel, ADU | Discovery Bay · Contra Costa County | — | — |
| Jb Construction | Jesse Benjamin Horn | — | (415) 636 0285 | GC, remodel, ADU | Richmond · Contra Costa County | — | — |
| Jb Infrastructure | Jb Infrastructure | — | (925) 817 9875 | Other | Concord · Contra Costa County | — | — |
| Jb Mechanical INC DBA Mas Service | John Alan Billheimer | — | (888) 314 0451 | HVAC | Antioch · Contra Costa County | — | — |
| Jburns Builder | Jburns Builder | — | (925) 699 7959 | GC, remodel, ADU | Martinez · Contra Costa County | — | — |
| Jc Climate Control Technology's INC | Jorge Ivan Arenas Azuara | — | (925) 849 5334 | HVAC | Concord · Contra Costa County | — | — |
| Jc Concrete | Jc Concrete | interested@domainmarket.com | (510) 963 0211 | Other | Antioch · Contra Costa County | — | — |
| Jc Construction | Julio Cesar Ramirez Sanchez | — | (650) 518 4367 | GC, remodel, ADU | Antioch · Contra Costa County | — | — |
| Jc Construction & Structural INC | Justin Douglas Caddy | — | (510) 239 3101 | GC, remodel, ADU | Bay Point · Contra Costa County | — | — |
| Jc Services Corp | Juvie Derafera Cuison | — | (510) 706 6477 | GC, remodel, ADU | Martinez · Contra Costa County | — | — |
| Jc Tree Service | Marcos Emilio Ulloa | — | (925) 679 1400 | Tree | Antioch · Contra Costa County | — | — |
| Jc Yard Maintenance & Landscaping | Jc Yard Maintenance & Landscaping | — | (925) 812 2146 | Windows, patio, painters | Oakley · Contra Costa County | — | — |
| Jcd Remodeling LLC | Velazquez Isaac Calderon | — | (510) 593 3556 | GC, remodel, ADU | Brentwood · Contra Costa County | — | — |
| Jce Plumbing INC | Juan Gonzalo Martinez | — | (415) 424 6161 | Other | Antioch · Contra Costa County | — | — |
| Jcj Counters INC | Jens Christian Jensen | info@jcjcounters.com | (925) 695 5341 | Other | Brentwood · Contra Costa County | — | — |
| Jcn Electric INC | Juan Carlos Navarrete Zavala | — | (415) 530 0491 | Electricians | Bay Point · Contra Costa County | — | — |
| Jd General Construction | Jd General Construction | %20hello@jd-generalconstruction.com | (925) 492-8959 | GC, remodel, ADU | Walnut Creek · Contra Costa County | — | — |
| Jd General Construction Group Corp | Duran De Luna Jose De Jesus | — | (925) 445 8304 | GC, remodel, ADU | Antioch · Contra Costa County | — | — |
| Jd Landscape And Irrigation | Jd Landscape And Irrigation | jdlandscaping415@gmail.com | (415) 532 9382 | Windows, patio, painters | Richmond · Contra Costa County | — | — |
| Jd Tile INC | Jimmie Carl Davis | — | (925) 757 8367 | GC, remodel, ADU | Antioch · Contra Costa County | — | — |
| Jd's Tree Service | Juan Diego Bautista | — | (925) 799 8330 | Other | Concord · Contra Costa County | — | — |
| Jdc Laboratory Construction Services INC | Jose Roberto Ramirez Cardona | — | (415) 900 6312 | GC, remodel, ADU | Antioch · Contra Costa County | — | — |
| Jds Construction Enterprise INC | Jose Jonathan Duran Salinas | — | (951) 426 1583 | GC, remodel, ADU | San Pablo · Contra Costa County | — | — |
| Jean Fogg Landscape | Jean Fogg Landscape | — | (925) 521 1545 | Windows, patio, painters | Concord · Contra Costa County | — | — |
| Jedco Consulting Engineers INC | Firas Abddulwadoud Jandali | — | (510) 703 0095 | GC, remodel, ADU | El Cerrito · Contra Costa County | — | — |
| Jeff Anderson Custom Finishes | Jeff Anderson Custom Finishes | — | (510) 234 8200 | Windows, patio, painters | Richmond · Contra Costa County | — | — |
| Jeff Bocek | Jeff Bocek | — | (925) 286 8603 | GC, remodel, ADU | Walnut Creek · Contra Costa County | — | — |
| Jeff Bullock | Jeff Bullock | chenowith52@gmail.com | (925) 525 9055 | GC, remodel, ADU | Pacheco · Contra Costa County | — | — |
| Jeff Cushing | Jeff Cushing | — | (925) 785 7743 | GC, remodel, ADU | San Ramon · Contra Costa County | — | — |