| Yuehuan Xu | Yuehuan Xu | — | (510) 458 7016 | GC, remodel, ADU | Fremont · Alameda County | — | — |
| Yujiang Pang | Yujiang Pang | — | (510) 648 4039 | GC, remodel, ADU | Fremont · Alameda County | — | — |
| Yung Cheng Hsieh | Yung Cheng Hsieh | — | (510) 468 5172 | GC, remodel, ADU | Fremont · Alameda County | — | — |
| Yuqi Tian | Yuqi Tian | — | (510) 455 5666 | GC, remodel, ADU | Pleasanton · Alameda County | — | — |
| Yv Builders | Neil Sharma | — | (925) 666 5057 | GC, remodel, ADU | Pleasanton · Alameda County | — | — |
| Yzw Construction INC | Jiuchuan Sun | — | (510) 378 5328 | GC, remodel, ADU | Fremont · Alameda County | — | — |
| Z & F Maintenance LLC | Andy Huy Kien Phung | — | (510) 213 9645 | Electricians | San Leandro · Alameda County | — | — |
| Z & L Cold Equipment Service | Lixin Zhan | — | (510) 541 4781 | HVAC | Hayward · Alameda County | — | — |
| Z & Y Construction INC | Zhu Zheng Gen | — | (510) 676 2174 | GC, remodel, ADU | Fremont · Alameda County | — | — |
| Z & Z Construction | Zhong Zhi-qiang | — | (408) 821 3531 | GC, remodel, ADU | Fremont · Alameda County | — | — |
| Z And Z Plumbing | Z And Z Plumbing | — | (510) 708 4237 | Other | San Leandro · Alameda County | — | — |
| Z K Painting Co | Zaharias Kratsas | — | (510) 377 1256 | Windows, patio, painters | Hayward · Alameda County | — | — |
| Z L Construction | Liu Zhuotian | — | (415) 819 0264 | GC, remodel, ADU | San Leandro · Alameda County | — | — |
| Z L Construction | Li Zhishi | — | (510) 303 0005 | GC, remodel, ADU | Union City · Alameda County | — | — |
| Z Lab Installation INC | Andre Robert Barancic | — | (925) 788 5182 | GC, remodel, ADU | Livermore · Alameda County | — | — |
| Z M C Products INC | Andrew M Cheung | — | (510) 226 9627 | Other | Fremont · Alameda County | — | — |
| Z V Professional Painting & Decorating INC | Zeus Balaam Velazquez | — | (510) 862 4822 | Windows, patio, painters | Hayward · Alameda County | — | — |
| Zachary Boelsterli | Zachary Boelsterli | — | (925) 771 0778 | GC, remodel, ADU | Castro Valley · Alameda County | — | — |
| Zakskorn Construction Company DBA Zcon Builders | Dani Tucker | — | (510) 444 4190 | GC, remodel, ADU | Oakland · Alameda County | — | — |
| Zaldana Construction | Cesar Edgardo Ramos Zaldana | zaldana.construction@hotmail.com | (510) 674 4319 | GC, remodel, ADU | Hayward · Alameda County | — | — |
| Zamora Home Improvement LLC | Zamora Acosta Gilberto | — | (510) 285 7248 | GC, remodel, ADU | Oakland · Alameda County | — | — |
| Zanderbuilt Corporation A California Corporation | Brennen Alexander | — | (510) 526 9907 | GC, remodel, ADU | Berkeley · Alameda County | — | — |
| Zeek's Discount Glass INC | Ouakouak Zouhir | zeeksdiscountglass@gmail.com | (510) 882 3971 | Windows, patio, painters | Castro Valley · Alameda County | — | — |
| Zeitz Electric | Daniel Joseph Zeitz | — | (510) 786 8084 | Electricians | Hayward · Alameda County | — | — |
| Zemm Construction | Rizwan Farooq Azam | — | (650) 924 3600 | GC, remodel, ADU | Fremont · Alameda County | — | — |
| Zen Fertigation INC | Binh Van Nguyen | — | (510) 573 0873 | Windows, patio, painters | Fremont · Alameda County | — | — |
| Zen Renovation Art | Christopher Kiwon Ro | — | (646) 591 9874 | GC, remodel, ADU | Berkeley · Alameda County | — | — |
| Zencom Cabling Solutions INC | Adam Glen Garvin | — | (510) 807 0955 | Other | Sunol · Alameda County | — | — |
| Zenith General Contractors Corp | Davis Jo Ann | — | (510) 376 4142 | GC, remodel, ADU | San Leandro · Alameda County | — | — |
| Zerk Construction | Matthew Norton Lovering | — | (628) 400 1308 | GC, remodel, ADU | Alameda · Alameda County | — | — |
| Zermeno's Custom Ironworks INC | Zermeno Alvaro | — | (510) 614 2900 | Other | Hayward · Alameda County | — | — |
| Zerromax Electric | Rosalio Haro-Flores | — | (510) 520 1392 | Electricians | Oakland · Alameda County | — | — |
| Zeven Garage Door INC | Edgar Jesus Zapata Garces | — | (408) 429 9982 | Other | Fremont · Alameda County | — | — |
| Zhangcai Zhen | Zhangcai Zhen | — | (510) 368 3929 | GC, remodel, ADU | Oakland · Alameda County | — | — |
| Zheng Chai | Zheng Chai | — | (510) 474 8070 | GC, remodel, ADU | Newark · Alameda County | — | — |
| Zhenhua Zheng | Zhenhua Zheng | — | (408) 680 9199 | GC, remodel, ADU | Fremont · Alameda County | — | — |
| Zhitian Shao Construction | Shao Zhitian | — | (510) 676 6350 | GC, remodel, ADU | Newark · Alameda County | — | — |
| Zhong Yuan General Service | Andy Phung | — | (510) 396 6316 | Electricians | San Leandro · Alameda County | — | — |
| Zhu Wei Construction Corp | Zhu Weiqu | — | (510) 282 0268 | GC, remodel, ADU | San Leandro · Alameda County | — | — |
| Zi Builder INC | Zetao Yang | yang@zibuilder.com | (510) 693 1978 | GC, remodel, ADU | Dublin · Alameda County | — | — |