| Kwu Studio INC | Kyle William Usselton | — | (510) 200 8680 | GC, remodel, ADU | Berkeley · Alameda County | — | — |
| Kyda Construction | Andy Hui Zhu | — | (510) 717 4371 | Electricians | San Leandro · Alameda County | — | — |
| Kyriakos Avdoulos DBA Absolute Painting | Kyriakos Avdoulos DBA Absolute Painting | — | (510) 582 4500 | Windows, patio, painters | Castro Valley · Alameda County | — | — |
| L & J Demolition INC | Luis Miguel Arroyo Hernandez | — | (510) 529 8278 | Other | Castro Valley · Alameda County | — | — |
| L & L Landscaping INC | Ross Knazs | — | (844) 944 3050 | Windows, patio, painters | Livermore · Alameda County | — | — |
| L & L Quality Painting | Sanchez Miguel Lopez | — | (650) 307 9616 | Windows, patio, painters | Hayward · Alameda County | — | — |
| L & O Construction Renovation Corp | Eduardo Mercado Gabriel | — | (626) 421 5535 | GC, remodel, ADU | Pleasanton · Alameda County | — | — |
| L & T Construction | Johnny Xuan Nguyen | — | (510) 305 5628 | Electricians | Union City · Alameda County | — | — |
| L & Y Construction | Ying Quan Liang | — | (415) 613 6108 | GC, remodel, ADU | San Leandro · Alameda County | — | — |
| L 7 Principal Development | L 7 Principal Development | — | (415) 990 2139 | GC, remodel, ADU | Hayward · Alameda County | — | — |
| L A A C Roofing Services | Lara Hector | — | (510) 944 9588 | Other roofers | San Leandro · Alameda County | — | — |
| L C Construction LLC | Lance Anthony Cook | — | (925) 231 7311 | GC, remodel, ADU | Livermore · Alameda County | — | — |
| L E Baca Construction Services | Lawrence Ernest Baca | — | (510) 912 0911 | GC, remodel, ADU | Newark · Alameda County | — | — |
| L E Electric INC | Leland Liu Guan | — | (510) 590 8338 | Electricians | Castro Valley · Alameda County | — | — |
| L F Electric | Luis Armando Figueroa | — | (415) 261 0517 | Electricians | Oakland · Alameda County | — | — |
| L G Design And Construction Co | Li Geng Zheng | — | (510) 318 1118 | GC, remodel, ADU | Albany · Alameda County | — | — |
| L H P Electrical Company | Zhang Shouliang | — | (510) 759 4942 | Electricians | Newark · Alameda County | — | — |
| L J Construction | Feng Li Ji | — | (415) 335 6999 | GC, remodel, ADU | Hayward · Alameda County | — | — |
| L J Interiors INC | Lawrence Jon Borneman | joeb@ljinteriors.com | (925) 456 2216 | Other | Livermore · Alameda County | — | — |
| L J Kruse Co | William Louis Kruse | — | (510) 644 2497 | HVAC | Berkeley · Alameda County | — | — |
| L N D Plumbing | L N D Plumbing | — | (925) 399 2061 | Other | Livermore · Alameda County | — | — |
| L R T Construction LLC | Tsz Lok Pak | — | (510) 213 8868 | Electricians | Oakland · Alameda County | — | — |
| L Simcoe Custom Painting | L Simcoe Custom Painting | — | (510) 326 0920 | Windows, patio, painters | Piedmont · Alameda County | — | — |
| L V A Rescue | Juan Pedro Carrasco | — | (510) 331 8678 | GC, remodel, ADU | Hayward · Alameda County | — | — |
| L W Construction | Wu Liyu | — | (408) 712 2291 | GC, remodel, ADU | Fremont · Alameda County | — | — |
| L W Construction LLC | Liyu Wu | — | (408) 712 2291 | GC, remodel, ADU | Fremont · Alameda County | — | — |
| L&e Building Services INC DBA L&e Remodeling | Ignacio Juventino De Jesus Acosta | — | (650) 296 6343 | GC, remodel, ADU | Hayward · Alameda County | — | — |
| L&m Landscaping Service LLC | Max Andrew Arriola | — | (925) 487 0206 | Windows, patio, painters | Livermore · Alameda County | — | — |
| L2m Builders | Nelson Omar Lopez Valdez | hi@l2mbuilders.com | (510) 614 8769 | GC, remodel, ADU | San Leandro · Alameda County | — | — |
| La Bella's Pool Service & Supplies | Sharon Lee La Bella | — | (510) 886 3020 | Pool | Hayward · Alameda County | — | — |
| La Canada Tree Service | Raul Haro Senteno | — | (650) 222 8828 | Tree | Livermore · Alameda County | — | — |
| La Maison Construction | Chun-Chuan Ma | info@lamaisonconstruction.com | (510) 565 2090 | GC, remodel, ADU | Fremont · Alameda County | — | — |
| La Roza Construction INC | Kelly Rae Klein | info@larozaconstruction.com | (925) 961 1257 | GC, remodel, ADU | Pleasanton · Alameda County | — | — |
| Labat Custom Tile Service | Rick Jay Labat | — | (510) 206 2001 | Other | San Leandro · Alameda County | — | — |
| Lacatis Construction | Lacatis Eugene | — | (510) 406 0535 | GC, remodel, ADU | San Leandro · Alameda County | — | — |
| Lacayo Colt Plumbing & Heating INC | Mario Reynaldo Lacayo | — | (510) 336 3496 | HVAC | San Leandro · Alameda County | — | — |
| Ladder Electric INC | Andrew Edward Payne | andy@ladderelectric.com | (510) 300 7513 | Electricians | Fremont · Alameda County | — | — |
| Ladybug Construction Services | Glenn Gilbert Howe | — | (510) 529 1667 | GC, remodel, ADU | Oakland · Alameda County | — | — |
| Ladybug Landscapes INC | White Timothy | — | (415) 987 6975 | Windows, patio, painters | Berkeley · Alameda County | — | — |
| Lafayette Iron Works & Company INC | David Timothy Ritchie | — | (925) 382 7164 | Other | Livermore · Alameda County | — | — |