Quantum Construction & Design
Home addition contractor based in Los Angeles. Licensed since 2020.
- License active
- Workers' comp on file
12 jobs on Los Angeles permits, 2024 to 2026: 6 home additions, 3 ADUs, 3 remodels. 85th most addition permits of 357 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 1061867, active in the state's records on Sep 23, 2026General buildingNo complaints or citations on the board's public record. | Checks out |
| Workers' comp? | Workers' comp policy on file with the stateThis covers their crew if someone is hurt. It is not insurance for your home. | On file |
| In business? | Licensed since 2020 | |
| Jobs on record | 12 jobs on Los Angeles permits, 2024 to 2026: 6 home additions, 3 ADUs, 3 remodelsTheir permits mention 3 garages, 1 bathroom.85th most addition permits of 357 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 1061867 on CSLB
Cost and timing
All addition jobs in Los Angeles: $38,000 to $120,000
Half of 10,836 city permits list an amount in this range. Permit amounts are often lower than what you pay.
- Second-story additions in Los Angeles: $75,000 to $200,000 (858 permits)
- Garage additions in Los Angeles: $48,000 to $110,000 (3,411 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 $100,000 (half list more, half less)
That is the figure written on the permit form, which can be far from what you pay. What addition jobs cost in Los Angeles.
Get 2 or 3 written quotes.
Permit timeline
Across Los Angeles, a addition permit stays open about about 13 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 addition jobs take.
Track record
4 jobs in the last 12 months, down from 7 the year before
Where they work most
- 900395 jobs
- 900163 jobs
- 900622 jobs
- 900351 job
- 900261 job
Jobs by kind of work
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 |
|---|---|---|---|
| Aug 22, 2026 | AdditionDemo existing garage except 16.15 lf of footing and rebuild new all el | 90035 | $54,540 |
| Apr 7, 2026 | AdditionAddition & remodel to (e) S.F.D. (front bldg.) *** 1 of 3 *** | 90039 | $110,000 |
| Apr 7, 2026 | Addition | 90039 | $110,000 |
| Apr 7, 2026 | ADU | 90039 | $110,000 |
| Mar 30, 2025 | AdditionAddition and convert (e) detached garage to adu per ordinance and lamc | 90016 | $95,000 |
| Mar 30, 2025 | ADUAddition and convert (e) detached garage to adu per ordinance and lamc | 90016 | $95,000 |
| Mar 13, 2025 | Remodel(1) Kitchen remodel for residential buildings (no structural changes). MEPs INCLUDED | 90026 | $8,500 |
| Mar 4, 2025 | RemodelAddition & remodel to (e) S.F.D. (front bldg.) *** 1 of 3 *** | 90039 | $110,000 |
| Mar 4, 2025 | Remodel | 90039 | $110,000 |
| Sep 25, 2024 | AdditionADDITION TO (E) GARAGE TO CREATE (N) ADU PER LAMC 12.22 A.33(c) AND | 90062 | $105,000 |
| Sep 25, 2024 | ADUADDITION TO (E) GARAGE TO CREATE (N) ADU PER LAMC 12.22 A.33(c) AND | 90062 | $105,000 |
| Feb 19, 2024 | AdditionAdd 25'-0" x 15'-3" bedroom and bathroom to the (e) sfd | 90016 | $45,000 |
What to ask before you hire
About Quantum Construction & Design
- Ask what the warranty covers and for how long, in writing.
Worth asking any home addition contractor
- Can you show me proof of liability insurance and your bond?
- Do you handle the plans and engineering, or do I hire them?
- Who will run the job day to day, and who are the subcontractors?
- Who pulls the permits, and what is the payment schedule?
Get a quote from Quantum Construction & Design
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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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