| North Cal Painting LLC | Maximiliano Domingo Borgen | service@northcalpainting.com | (415) 432 9515 | Windows, patio, painters | Oakland · Alameda County | — | — |
| North Star Building Solutions INC | Erik Gordon Amos | — | (510) 513 3321 | GC, remodel, ADU | Fremont · Alameda County | — | — |
| North Star Electrical LLC | Wei Liang Kuang | — | (626) 688 2038 | Electricians | San Leandro · Alameda County | — | — |
| North Valley Construction Framing INC | Jose Manuel Jimenez | — | (510) 396 5739 | GC, remodel, ADU | Hayward · Alameda County | — | — |
| North View Construction LLC | Pedro Cuevas | — | (510) 259 8087 | GC, remodel, ADU | Oakland · Alameda County | — | — |
| Northcal Fire Protection | Northcal Fire Protection | — | (510) 394 8603 | Other | Castro Valley · Alameda County | — | — |
| Northern California Nail Company INC | Francis Howard Jr Tankersley | — | (925) 443 7239 | GC, remodel, ADU | Livermore · Alameda County | — | — |
| Northern Structural INC | Gabriel Raphael Seyller | — | (510) 258 6469 | Other | Castro Valley · Alameda County | — | — |
| Northgate Environmental Management INC | Anand Sudheer Helekar | — | (949) 716 0050 | Other | Oakland · Alameda County | — | — |
| Northgate Excavation | Northgate Excavation | — | (510) 812 4168 | Other | Oakland · Alameda County | — | — |
| Northland Control Systems INC | Pierre Alain Trapanese | — | (833) 811 4185 | Other | Fremont · Alameda County | — | — |
| Northstone Builders LLC | Gregory Thomas Malley | — | (213) 608 2509 | GC, remodel, ADU | Alameda · Alameda County | — | — |
| Northup Construction INC | Kelly Winston Northup | — | (510) 368 4180 | GC, remodel, ADU | Castro Valley · Alameda County | — | — |
| Northwest Design And Construction INC | Mario Balin Lagula | — | (415) 518 4342 | GC, remodel, ADU | Hayward · Alameda County | — | — |
| Northwestern Electrical Systems INC | Curtis Ross Hawks | — | (510) 786 7400 | Electricians | Hayward · Alameda County | — | — |
| Northwood Design Partners INC | Michael Douglas Hayes | customerservice@northwooddesignpartners.com | (510) 731 6505 | Other | Union City · Alameda County | — | — |
| Nova Roofing | Moreno Hernandez Ponciano | — | (510) 851 2194 | Other roofers | Oakland · Alameda County | — | — |
| Novateck | Thuy Xuan Mai | — | (510) 727 5612 | Other | Castro Valley · Alameda County | — | — |
| Novus Electric | Jose Juan Cruz Perez | — | (510) 395 5361 | Electricians | Fremont · Alameda County | — | — |
| Nu Rev Communications INC | Bernadette Flores Galicha | — | (925) 980 2799 | GC, remodel, ADU | Livermore · Alameda County | — | — |
| Nugent Plastering | Kevin Joseph Nugent | impallari@gmail.com | (510) 303 1419 | Other | Castro Valley · Alameda County | — | — |
| Number One Hardwood Floors | Number One Hardwood Floors | — | (510) 220 2683 | Other | Alameda · Alameda County | — | — |
| Number One Hardwood Floors INC | Tai Van Nguyen | — | (510) 220 2683 | Other | Alameda · Alameda County | — | — |
| Nunes Painting & Decorating | Nunes Painting & Decorating | — | (510) 589 2135 | Windows, patio, painters | Castro Valley · Alameda County | — | — |
| Nurture Source Partners LLC | Benjamin Joseph Kimmich | — | (510) 868 1021 | GC, remodel, ADU | Berkeley · Alameda County | — | — |
| Nuvation Design Builders | Juan Mario Hall | — | (510) 990 8334 | GC, remodel, ADU | Oakland · Alameda County | — | — |
| Nuvera Construction INC | Jeffrey Benoit Lawrence | — | (925) 309 8888 | GC, remodel, ADU | Pleasanton · Alameda County | — | — |
| Nuyten Construction | John Andreas Nuyten | — | (510) 928 0368 | GC, remodel, ADU | Hayward · Alameda County | — | — |
| Nvc Chiller INC | Julio Andres Paz D'abbraccio | sales@nvcchiller.com | (213) 887 4934 | HVAC | Dublin · Alameda County | — | — |
| Nvision Contractors INC | John Iii Brown | — | (510) 894 8886 | GC, remodel, ADU | Fremont · Alameda County | — | — |
| Nwmec INC DBA Moffitt Electric | William John Moffitt | — | (510) 708 9703 | Electricians | Hayward · Alameda County | — | — |
| Nx Landscaping | Nx Landscaping | — | (510) 299 2862 | Windows, patio, painters | Hayward · Alameda County | — | — |
| Nxt Construction LLC | Nicholas James Haycock | — | (925) 699 8208 | GC, remodel, ADU | Dublin · Alameda County | — | — |
| Nzilani Glass Conservation | Ariana Renee Makau | — | (510) 995 0477 | Windows, patio, painters | Oakland · Alameda County | — | — |
| O B Construction | Onofre Valentino Bustamante | — | (408) 515 5709 | GC, remodel, ADU | San Lorenzo · Alameda County | — | — |
| O C Jones & Sons INC | Gregory Richard Souder | — | (510) 526 3424 | Other | Berkeley · Alameda County | — | — |
| O I Buildworks | O I Buildworks | — | (650) 283 8298 | GC, remodel, ADU | Hayward · Alameda County | — | — |
| O P G Construction | Oliver Primitivo Garcia | — | (925) 989 2462 | GC, remodel, ADU | Livermore · Alameda County | — | — |
| O Resendes Painting Co | Octavio Albert Amara Resendes | — | (510) 418 5355 | Windows, patio, painters | Hayward · Alameda County | — | — |
| O S E Horizon Enterprise INC Horizon Renovation | Ngai Ho Kent Tsang | — | (510) 567 3583 | GC, remodel, ADU | Oakland · Alameda County | — | — |