Design-Build General Contractor in Los Angeles
Built to a standardyou can verify.
Luxury remodels, room additions, ADUs and ground-up homes across most of Los Angeles County, plus Long Beach, Orange County, Oxnard and Pasadena. Delivered on a fixed-price proposal, with design, engineering, permits and construction handled under one contract.
● Typical reply within one business day . No obligation . For home improvement contracts in California the down payment is capped at $1,000 or ten percent, whichever is less. We do not ask for more.
What We Build
One contract. Design, permits, engineering and construction.
You are not managing an architect, a plan-check expediter, three subs and a supplier. You are managing us, and we publish the range before you commit.
Photo: completed Taj Mahal quartzite island kitchen, EncinoKitchen Remodeling
Full gut to finish: layout, structural openings, Title 24-compliant electrical and mechanical, stone fabrication and installation.
Photo: Dekton book-matched primary bath, wall-hung fixturesBathroom Remodeling
Waterproofing done to code and documented, curbless showers, book-matched slab walls, and accessible / aging-in-place layouts.
Photo: whole-home renovation, before / after pairWhole-Home Renovation
Down to the studs and back up: structural, MEP replacement, envelope, finishes and landscape, phased so you know what happens each week.
Photo: detached 800 sq ft ADU, Sherman Oaks, exterior + interiorADUs & Garage Conversions
Detached, attached and JADU. We run feasibility against your actual parcel, then use LADBS pre-approved standard plans where they shorten plan check.
Photo: second-story addition framed and finished, Studio CityRoom Additions & Second Stories
Foundation and shear engineering, tie-in detailing, and a roof line that reads as original, not an addition bolted onto the back of the house.
Photo: ground-up custom home, hillside, San Gabriel ridgeline backdropCustom Homes & Fire Rebuilds
Ground-up construction, hillside grading, and Chapter 7A-compliant rebuilds in wildfire zones, including LA's expedited self-certification pathway.
Commercial & Tenant Improvement
Retail, medical, office and multifamily. ADA path-of-travel, fire-life-safety, and inspections sequenced against your lease commencement date.
Multifamily & Development
Small-lot subdivisions, SB 1211 multifamily ADU programs, and value-engineering support for developers before you close on the parcel.
Starting prices are real floors from completed projects at our entry specification, not teaser numbers. We tell you at the first meeting which line items move yours, and why.
Before You Ask Anyone for a Bid
Find out what your lot can actually hold.
Enter your address and we'll return a written feasibility snapshot: zoning, setbacks, buildable footprint, likely permit path, and a realistic budget band for your scope. Free, and yours to take to any contractor.
- Parcel zoning, overlays and hillside / fire-zone status
- Maximum ADU size and setback envelope under current state law
- Whether an LADBS pre-approved standard plan fits, and how much plan-check time it saves
- A budget band with the line items that actually move it
Recent Work
Named projects. Real neighborhoods. Dated.
Every project below links to a full case study: scope, square footage, permit path, timeline, materials specified, and what we would do differently.
Hero photo: 3:2.5 landscapeEncino, 2026
Louise Avenue Kitchen & Great Room
620 sq ft14 weeksTaj Mahal quartzite
Hero photo: 3:2.5 landscapeSherman Oaks, 2026
Dickens Street Detached ADU
798 sq ft2 bed / 2 bathStandard plan
Hero photo: 3:2.5 landscapeStudio City, 2025
Woodbridge Whole-Home Renovation
3,240 sq ft9 monthsFull MEP
Hero photo: 3:2.5 landscapeTarzana, 2025
Wells Drive Primary Suite Addition
540 sq ft11 weeksShear engineered
Hero photo: 3:2.5 landscapeWoodland Hills, 2025
Del Moreno Primary Bath
180 sq ft7 weeksDekton slab
Hero photo: 3:2.5 landscapeCalabasas, 2024
Mulholland Ridge Custom Home
5,100 sq ft18 monthsHillside grading
Drag to compare
Del Moreno Drive, Woodland Hills. A 1978 tract bathroom rebuilt as a book-matched primary suite, same footprint, re-planned.
The Process
Five stages. You always know which one you're in.
Most construction anxiety is not about quality. It's about not knowing what happens next. Here is what happens next.
01
Consultation & Feasibility
We walk the property, pull parcel and zoning data, and tell you plainly whether the project you want is possible at the budget you have.
Week 102
Design & Fixed-Price Proposal
Architectural drawings, structural engineering, Title 24 calcs and material selections, priced line by line before a single permit is filed.
Weeks 2 to 803
Permitting
We file, we sit in plan check, we answer the corrections. Where an LADBS pre-approved standard plan fits, we use it and cut months out.
Weeks 6 to 2004
Construction
One dedicated project manager, a weekly written update with photos, and a live schedule you can open on your phone. Inspections sequenced, not improvised.
Per scope05
Handover & Warranty
Final inspection sign-off, a closeout package with permits, warranties and as-builts, and a punch walk with a written closeout package.
OngoingRisk, Removed
The Mamos Standard
Four commitments, in the contract, not in the brochure. Three of them are California law that most contractors quietly ignore.
Never more than 10% down
For home improvement contracts in California the down payment is capped at $1,000 or ten percent, whichever is less. We do not ask for more.
CSLB Home Improvement Contracts ↗Fixed-price proposal, line by line
You see allowances, unit costs and exclusions before you sign. Anything genuinely unforeseeable gets a written change order with a price, approved before the work happens, never after.
Permits pulled in our name
If a contractor asks you to pull the owner-builder permit yourself, they are moving liability onto you. We pull it, we carry it, and we meet the inspector.
Fixed-price proposal
Issued after a site inspection, so the number holds. Allowances and finishes are set while we are standing on your property, not guessed at from a desk.
Verify Us Before You Call Us
CSLB License #1092889 is active, bonded and insured.
Don't take our word for it. The State of California publishes our license status, bond, workers' compensation coverage and complaint history. It takes about forty seconds.
Where Projects Start
We publish where we start. Most contractors won't.
These are real starting prices for work built to code in the San Fernando Valley. Where your project lands above that depends on scope, site and specification, and we tell you exactly which line items move it.
| Scope | Starting at | What moves the number most |
|---|---|---|
| Kitchen, full gut | from $45,000 | Moving plumbing or gas, structural openings, cabinetry tier, slab selection |
| Bathroom remodel | from $22,000 | Curbless shower, slab walls vs. tile, relocating the toilet stack |
| Room addition | from $225 / sq ft | Foundation type, whether the roof line has to change, panel upgrade |
| Detached ADU (400 to 600 sq ft) | from $149,000 | Utility trenching distance, standard plan vs. custom, site access for equipment |
| Garage conversion ADU | from $85,000 | Existing slab and footing condition, egress, fire separation |
| Whole-home renovation | from $180,000 | Full MEP replacement, structural retrofit, envelope and landscape scope |
| Ground-up custom home | from $375 / sq ft | Hillside vs. flat, grading and shoring, level of finish and millwork |
Starting prices reflect completed projects at our entry specification and exclude land, furniture, and permit or school fees paid directly to the jurisdiction. Figures shown are placeholders for this prototype and must be replaced with numbers you would actually sign a contract at.
Clients
Named. Local. Specific about what went right.
Every review below is verifiable on the platform it came from. We link out rather than retype.
“They found a beam issue on day three that two other bidders had missed entirely. It cost more, but they showed me the engineer's letter, wrote the change order, and the schedule never moved.”
★★★★★
“The ADU rents for enough to cover most of our mortgage. What I remember most is that the weekly photo update never once skipped a week, even the week nothing happened.”
★★★★★
“We interviewed four contractors. Mamos was the only one who told us what we wanted wasn't worth the money and proposed something smaller. That's why we hired them.”
★★★★★
Placeholder copy for this prototype. Replace with verbatim reviews from your live Google, Yelp and Houzz profiles. Never write testimonials on a client's behalf.
Built With Us?
Tell people what actually happened.
Good or bad. A review that names the neighborhood, the scope and one specific thing we did right or wrong is worth more to the next homeowner than ten generic five-star ratings.
Set your review links. Open inc/config.php and paste your Google, Yelp and Houzz review URLs into MAMOS_REVIEW_GOOGLE, MAMOS_REVIEW_YELP and MAMOS_REVIEW_HOUZZ. Until then the buttons stay hidden rather than leading nowhere.
We ask every client for a review, not just the happy ones. If something went wrong, we would rather hear it from you first, so call (818) 934-0075 or use the form. Either way, post publicly too.
Thank you.
We will verify it against our project records and publish it within a day or two.
Where We Build
San Fernando Valley and the Westside.
Each area below gets its own page: local permit jurisdiction, projects we've completed there, and the constraints specific to that neighborhood.
Straight Answers
The questions people ask before they call.
How much does an ADU cost in Los Angeles right now?
Detached ADUs start at $149,000 in the San Fernando Valley, and garage conversions start at $85,000. Where you land above that comes down to four things: how far utilities have to be trenched, whether the site is accessible to equipment, whether a pre-approved standard plan fits your lot, and your finish level. We walk you through all four at the consultation so the number stops being a mystery.
Can I sell my ADU separately from my house?
Not in the City or County of Los Angeles. AB 1033 allows cities to opt in to separate ADU condo sales, but LA has not adopted it. A handful of California cities have. If separate sale is central to your plan, tell us at the consultation. It changes what we'd recommend building.
How long does permitting take?
For an ADU using an LADBS pre-approved standard plan, often 6 to 10 weeks. For a custom design, plan on 3 to 6 months through plan check with corrections. Additions and whole-home work vary widely with structural scope and whether the property is in a hillside or fire hazard zone. We give you a jurisdiction-specific estimate at feasibility, not a generic one.
What deposit will you ask for?
The lesser of $1,000 or 10% of the contract price. That is the legal maximum in California for home improvement work, and we don't exceed it. Everything after that is tied to completed milestones. If any contractor asks for 30% or 50% up front, that alone is a reason to walk. CSLB explains it here.
Do you handle fire rebuilds in the Palisades and Altadena?
Yes. Rebuilds in wildfire zones trigger Chapter 7A requirements: ignition-resistant exteriors, ember-resistant vents, Class A roofing and tempered glazing. The City of LA's expanded self-certification pathway has cut approval times substantially for Palisades rebuilds. We'll tell you at feasibility whether a like-for-like rebuild or a redesign gets you into the house faster.
Are you licensed, bonded and insured?
CSLB License #1092889, active, with a contractor's bond, general liability and workers' compensation coverage. You can confirm all of it, including any complaint history, directly with the State at cslb.ca.gov. We'd rather you checked.
Photo: project manager with clients on site, warm daylightStart Here
Let's find out if this is a fit.
A consultation is a conversation, not a sales call. We'll look at the property, talk honestly about budget, and tell you if we're the wrong firm for the job.
Thank you, we've got it.
A project manager will be in touch within one business day. If it's urgent, call (818) 934-0075.