Rios William A
ADU builder based in Downey. Licensed since 2005.
- License active
- No workers' comp: the business told the state it has no employees
5 ADU jobs on Los Angeles permits, 2024 to 2025. 104th most ADU permits of 271 contractors in Los Angeles.
What the public records show
From the state's license records and the city's permits, one question at a time.
| Question | Records show | Mark |
|---|---|---|
| Licensed? | License 866335, active in the state's records on Sep 23, 2026General building, fire protectionNo complaints or citations on the board's public record. | Checks out |
| Workers' comp? | No workers' comp: the business told the state it has no employeesThis covers their crew if someone is hurt. It is not insurance for your home. | Ask them |
| In business? | Licensed since 2005 | |
| Jobs on record | 5 ADU jobs on Los Angeles permits, 2024 to 2025Every permit we have for them is ADU.They are based in Downey. Work outside Los Angeles is not in these records.104th most ADU permits of 271 licensed contractors in Los Angeles. That counts jobs, not quality.Our Los Angeles permit records cover September 2023 to September 2026. |
Records: the state license board and City of Los Angeles permits.
State license board record
Last checked Oct 4, 2026. This may have changed. Check it on CSLB.
No complaints or citations on the board's public record.
Source: California Contractors State License Board, checked Oct 4, 2026. Look up license 866335 on CSLB
Cost and timing
All ADU jobs in Los Angeles: $35,000 to $120,000
Half of 9,338 city permits list an amount in this range. Permit amounts are often lower than what you pay.
- Detached ADUs in Los Angeles: $46,000 to $121,000 (3,485 permits)
- Garage conversions in Los Angeles: $30,000 to $65,000 (3,524 permits)
- Junior ADUs in Los Angeles: $20,000 to $50,000 (768 permits)
How to read this range
Contractors write a job value on the permit form, and the city uses it to set the permit fee. It is not the contract price, and it is often lower than what you pay. A quarter of the permits list less than this range, and a quarter list more. Use it to see if a quote is in the normal range.
Permit value (not a price)
Their typical permit lists $480,000 (half list more, half less)
That is the figure written on the permit form, which can be far from what you pay. What ADU jobs cost in Los Angeles.
Get 2 or 3 written quotes.
Permit timeline
Across Los Angeles, a ADU permit stays open about about 12 months, from permit to final inspection
This is not how long the crew works at your home: most of it is waiting for the inspection. Ask them how many days the work takes. Waiting for the permit adds about about 4 months. How long ADU jobs take.
Track record
Where they work most
- 905013 jobs
- 900331 job
- 900041 job
Latest jobs
Permit values are what the contractor wrote on the permit form, not what the owner paid.
| Date | Work | ZIP | On the permit form |
|---|---|---|---|
| Oct 22, 2025 | ADU(n) 2-story duplex with attached accessory dwelling unit per la | 90501 | $883,000 |
| Oct 1, 2025 | ADUNew two story adu w/ attached garage | 90033 | $125,000 |
| Mar 12, 2025 | ADUProposed 3-story duplex w/attached adu (front unit) | 90501 | $480,000 |
| Mar 10, 2025 | ADUProposed 3-story duplex with attached adu -front unit | 90501 | $480,000 |
| Nov 10, 2024 | ADU(n) 3-story duplex with attached 2-car garage and accessory dwelling u | 90004 | $446,874 |
What to ask before you hire
About Rios William A
- Ask who will do the work. Anyone they pay to work on your home must be covered by workers' comp.
- Ask what the warranty covers and for how long, in writing.
Worth asking any ADU builder
- Can you show me proof of liability insurance and your bond?
- Do you handle the plans, engineering and utility hookups, or do I?
- How long from permit to the final inspection on your last three ADUs?
- What is the payment schedule, and what is extra?
Get a quote from Rios William A
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Your job room keeps the request, your photos and every reply in one place, with an assistant that checks prices against city permits. Keep its link: it is the key to your job.
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