| Green Valley Landscaping Corp | Orozco Alejandro Salvio | sales@greenvalleylandscaping.com | (415) 619 8055 | Windows, patio, painters | San Pablo · Contra Costa County | — | — |
| Green View Tree Service | Rosas Cirilo | — | (925) 826 8069 | Tree | Concord · Contra Costa County | — | — |
| Green-valley Landscape | Green-valley Landscape | — | (209) 604 3664 | Windows, patio, painters | Discovery Bay · Contra Costa County | — | — |
| Greengo Landscaping INC | James Matthew Zygutis | — | (925) 937 4008 | GC, remodel, ADU | Walnut Creek · Contra Costa County | — | — |
| Greenstar Builders INC | Evgeni Rybakov | — | (415) 359 4070 | GC, remodel, ADU | Danville · Contra Costa County | — | — |
| Greentech Industry INC | Radoslav| Rakle V Radoslav Denchev Raklev | — | (415) 609 4500 | GC, remodel, ADU | Pleasant Hill · Contra Costa County | — | — |
| Greer Painting | Greer Painting | — | (510) 409 2297 | Windows, patio, painters | Lafayette · Contra Costa County | — | — |
| Greg Gayler Construction Co | Gregory Allen Gayler | — | (510) 755 4967 | GC, remodel, ADU | Pittsburg · Contra Costa County | — | — |
| Greg Hornnes & Sons | Greg Hornnes & Sons | — | (925) 209 6631 | Other | Brentwood · Contra Costa County | — | — |
| Greg Muyskens Contractor INC | Gregory Scott Muyskens | — | (925) 998 4661 | GC, remodel, ADU | Danville · Contra Costa County | — | — |
| Greg Rossi Tile | Greg Rossi Tile | — | (925) 351 7701 | Other | Martinez · Contra Costa County | — | — |
| Greg Sage DBA Green Mountain Builder | Green Mountain Builder | — | (510) 418 7978 | GC, remodel, ADU | Kensington · Contra Costa County | — | — |
| Gregg De Haan Construction | Gregg Douglas De Haan | — | (510) 815 4421 | GC, remodel, ADU | Walnut Creek · Contra Costa County | — | — |
| Gregg Pastorino Floorcovering | Gregg Pastorino Floorcovering | — | (925) 330 1269 | GC, remodel, ADU | Martinez · Contra Costa County | — | — |
| Gregorio Salgado | Gregorio Salgado | — | (925) 434 6706 | Other | Antioch · Contra Costa County | — | — |
| Gregorio Tree Service INC | Maria Del Carmen Sanchez | — | (510) 776 6831 | Tree | Martinez · Contra Costa County | — | — |
| Gregory Kennedy | Gregory Kennedy | — | (415) 419 1115 | GC, remodel, ADU | Martinez · Contra Costa County | — | — |
| Gregory L Cole Construction Company | Gregory Lee Cole | — | (925) 954 4607 | GC, remodel, ADU | Concord · Contra Costa County | — | — |
| Gregory R Brown Custom Builders INC | Gregory Robert Brown | — | (925) 934 4280 | GC, remodel, ADU | Moraga · Contra Costa County | — | — |
| Gregory Santos | Gregory Santos | — | (415) 410 1087 | GC, remodel, ADU | Concord · Contra Costa County | — | — |
| Gregory-jardine Flooring | Thomas Paul Gregory | — | (925) 382 4676 | Other | Martinez · Contra Costa County | — | — |
| Griffin Tile & Marble Co | Robert Edward Griffin | — | (925) 787 0686 | Other | Concord · Contra Costa County | — | — |
| Griffin/swinerton A Joint Venture | Structures INC Griffin | — | (925) 602 6400 | GC, remodel, ADU | Concord · Contra Costa County | — | — |
| Griffin/swinerton LLC | Mark Gregory Hoglund | — | (925) 602 6400 | GC, remodel, ADU | Concord · Contra Costa County | — | — |
| Grigor H Malinov | Grigor H Malinov | — | (925) 787 4293 | Windows, patio, painters | Walnut Creek · Contra Costa County | — | — |
| Gripe Construction INC | Timothy Vance Gripe | — | (925) 408 3964 | GC, remodel, ADU | Clayton · Contra Costa County | — | — |
| Grizzly Bear Plumbing LLC | Todd Clifford Wheat | grizzlybearplumbing@gmail.com | (925) 765 5266 | Other | Martinez · Contra Costa County | — | — |
| Grizzly INC | Gary Lynn Mahloch | — | (925) 672 4447 | GC, remodel, ADU | Clayton · Contra Costa County | — | — |
| Ground Level Construction INC | Joseph Andrew Romeo | — | (925) 446 6084 | HVAC | Concord · Contra Costa County | — | — |
| Grounded & Green Electric | Ronald Loewen Perry | — | (925) 408 2668 | Electricians | Lafayette · Contra Costa County | — | — |
| Groundlevel Construction | Joseph Andrew Romeo | — | (925) 446 6084 | GC, remodel, ADU | Concord · Contra Costa County | — | — |
| Groundlevel-overaa Joint Venture 2 | C & Co Overaa | — | (925) 446 6084 | HVAC | Concord · Contra Costa County | — | — |
| Groundworks INC | Bryan Craig Lucay | — | (925) 513 0300 | GC, remodel, ADU | Brentwood · Contra Costa County | — | — |
| Group H Construction INC | Vicente Hernandez | — | (510) 779 4913 | GC, remodel, ADU | San Pablo · Contra Costa County | — | — |
| Grout Solutions | Grout Solutions | — | (925) 680 4662 | Other | Concord · Contra Costa County | — | — |
| Grout Wizard | Grout Wizard | — | (925) 866 5000 | Other | Pittsburg · Contra Costa County | — | — |
| Grover Electric | Richard Allen Grover | — | (925) 285 9657 | Electricians | Danville · Contra Costa County | — | — |
| Grovestrong Construction Services LLC | Robert Scott Flaherty | — | (510) 300 4360 | GC, remodel, ADU | Danville · Contra Costa County | — | — |
| Grow Plenty | Grow Plenty | maezing@growplenty.com | (510) 685 1170 | Windows, patio, painters | Richmond · Contra Costa County | — | — |
| Growth Builders | Growth Builders | — | (510) 541 1398 | GC, remodel, ADU | Rodeo · Contra Costa County | — | — |