Cornerstone Construction and Design
Home addition contractor based in Los Angeles. Licensed since 2000.
- License active
- Workers' comp on file
15 jobs on Los Angeles permits, 2023 to 2026: 6 home additions, 5 remodels, 3 ADUs, 1 roofing job. 68th 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 775449, 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 2000 | |
| Jobs on record | 15 jobs on Los Angeles permits, 2023 to 2026: 6 home additions, 5 remodels, 3 ADUs, 1 roofing jobTheir permits mention 1 basement, 1 porch, 1 garage.68th 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 775449 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 $72,500 (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, up from 3 the year before
Where they work most
- 900394 jobs
- 900263 jobs
- 900272 jobs
- 900312 jobs
- 900412 jobs
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 |
|---|---|---|---|
| Jan 5, 2026 | AdditionSecond story addition to existing two-story single-family dwell | 90039 | $50,000 |
| Jan 5, 2026 | AdditionFirst floor addition to existing single family dwelling w/ garag | 90039 | $40,000 |
| Nov 9, 2025 | AdditionAddition (472 sf) and remodel to (e) 2-story sfd with basement and att | 90027 | $120,000 |
| Sep 25, 2025 | RemodelAddition and remodel to (E) one story single family dwelling | 90042 | $80,000 |
| Jul 31, 2025 | Addition, 530 sq ftAddition of 530 sqft to single family dwelling of accessory dwelling | 90039 | $100,000 |
| Jul 31, 2025 | ADU, 530 sq ftAddition of 530 sqft to single family dwelling of accessory dwelling | 90039 | $100,000 |
| Nov 26, 2024 | ADU(n) 2-story accessory dwelling unit with 2-car garage per lamc 12.22.a | 90027 | $142,208 |
| Jul 30, 2024 | ReroofReplace drywall (no new walls added) for single family dwellings and duplexes only | 90031 | $142,571 |
| Jul 30, 2024 | RemodelReplace drywall (no new walls added) for single family dwellings and duplexes only | 90031 | $142,571 |
| Apr 29, 2024 | AdditionProposed int/ext remodel - enclose existing front porch to create new | 90041 | $35,000 |
| Feb 27, 2024 | RemodelExisitng 2 story SFD. Remodeling 1st and 2nd floor | 90068 | $50,000 |
| Nov 20, 2023 | AdditionConverting existing garage to ADU with addition "COMPLY WITH DE | 90026 | $95,000 |
| Nov 20, 2023 | ADUConverting existing garage to ADU with addition "COMPLY WITH DE | 90026 | $95,000 |
| Oct 3, 2023 | RemodelProposed int/ext remodel - enclose existing front porch to create new entry & enclose rear patio… | 90041 | $35,000 |
| Jul 12, 2023 | RemodelInterior kitchen remodel/repair (no changes in walls or openings) | 90026 | $25,000 |
What to ask before you hire
About Cornerstone Construction and 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 Cornerstone Construction and Design
Five quick questions. We pass your request to Cornerstone Construction and Design.
Request for Cornerstone Construction and Design
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Sent. We have your request.
We pass it to Cornerstone Construction and Design. Replies usually come within a few days.
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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