31O Development Inc
BLOS ANGELES, CA 90049
(310) 869 4745View profileLicensed under Class B (General Building)
Find CSLB-licensed ADU contractors in Whittier, CA. Every listing shows an active licence number you can check yourself.
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Get matched with a licensed proAn accessory dwelling unit is a small building with all of a large one’s obligations. It needs its own foundation, its own utility connections, and its own path through plan check — and unlike a remodel, it adds a dwelling, so the questions about setbacks, parking, fire separation and utility capacity are asked seriously.
In practice the schedule is dominated by approvals rather than construction. State law has narrowed what a city can refuse and set time limits on review, but City of Whittier still decides what your specific parcel allows. Confirm your local rules first — a contractor who tells you the rules without asking your address has not looked.
An ADU is a new structure, not an alteration, which puts it under Class B (General Building). CSLB defines a general building contractor as one whose work involves structures requiring at least two unrelated trades — the classification that covers building something from the ground up.
Every contractor on this page holds an active Class B (General Building) licence recorded at a Whittier address, with the number linked to the CSLB record. Check it before you pay for design work. The register will not tell you whether someone has built an ADU before, so ask directly and ask to see one.
What the register cannot tell you is whether a contractor has taken an ADU through plan check in your jurisdiction specifically. Requirements and review times differ between cities and unincorporated county areas, and familiarity with one department is worth real money in weeks saved. Ask how many ADUs they have completed, where those were, and whether any needed revisions after submission. Ask as well whether the price includes impact fees and utility connection charges — those are frequently excluded, they are not small, and discovering it at invoice stage is the most common unpleasant surprise on an ADU.
Every licence number below links to its record at cslb.ca.gov, where you can confirm status and expiry yourself.
298 registered in Whittier · 23,334 active CLEAR licences across Los Angeles County · page 17 of 973
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Ask each contractor for three jobs finished in the last year, then actually call them. Ask what went wrong and how it was handled — every project has something, and the answer tells you more than a list of successes.
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Licence first. References second. Reviews last. Why that order.
Get matched with a licensed proThese sit under the same Class B (General Building) licence, so the same contractors are qualified for them.
An ADU is new construction, so it falls under Class B (General Building) — the general building classification for structures involving two or more unrelated trades. This page lists contractors the register records with that classification at a Whittier address.
The register shows 298 with an active licence in this classification at a Whittier address, and 23,334 across Los Angeles County. The same pool covers general contracting work, so those pages list the same contractors.
No. The register records classification and status, not project history or specialism, and we do not claim more than it holds. Ask each contractor how many ADUs they have completed and request an address you can go and look at.
City of Whittier. State law sets the outer limits, but setbacks, height, parking and utility requirements are applied locally and vary by parcel. Ask them before you commission drawings.