ADU Construction

More living space, more property value.

Detached ADUs, attached units, garage conversions, and junior ADUs across Los Angeles — design, permits, and construction handled end to end, on time and within budget.

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Projects completed
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Years building in LA
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Typical ADU investment
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Free ADU design ($3k–$5k)
License #773147
Licensed, bonded & insured
Free in-home design session
Free 3D design ($3k–$5k value)
3,000+ projects since 1996
Design-build, one roof
The Preferred approach

The ADU process, without the permit pain.

An ADU is the highest-return square footage most LA lots can add — rental income, space for family, and property value in one build. It’s also a project that lives or dies in zoning and permitting.

Our ADU specialists start with a comprehensive site evaluation: your property’s potential, zoning requirements, budget, and timeline, all reviewed before design begins. Then we produce detailed plans and 3D renderings — free when you build with us.

We handle every document — permit applications, city submissions, engineering — and our project managers run construction from foundation to finish with strict quality control.

What to expect

Typical cost & timeline by ADU type.

Real ranges from our completed projects. Your estimate is confirmed after the free site evaluation.

ADU typeTypical costTimelineNotes
Garage conversion$50,000–$150,0003–6 monthsUses existing structure
Attached ADU$80,000–$200,0005–10 monthsUp to 50% of main home size
Detached ADU$100,000–$300,000+6–12 monthsUp to 1,200 sq ft
Junior ADU (JADU)$20,000–$50,0002–4 monthsUnder 500 sq ft, simplified permits

Expect $200–$400 per square foot depending on type and finishes. Garage conversions and prefab approaches can run 20–30% less than ground-up builds.

Who this is for

For lots that should be earning their keep.

ADUs work for rental income, multi-generational living, guest space, and home offices — and California law has never made them more buildable.

These are the units we build most.

Rental-income units
Multi-generational living
Detached ADUs
Attached ADUs
Garage conversions
Junior ADUs (JADUs)
Above-garage units
Two-story ADUs
Why Preferred

Craft you can hold us to.

Design-build, one roof

Architects, designers, and builders on one team — from 3D renderings and permits to the final walkthrough, with no handoffs and no finger-pointing.

Free 3D design session

A free in-home design session with 3D renderings — a $3,000–$5,000 value when you build with us — so you see the space before a wall moves.

One accountable team

A 25-person team led by the same family since 1996 — with a dedicated project manager, regular updates, and a clean, organized site.

What’s included

Everything, handled.

Free 3D ADU design

Detailed architectural plans and 3D renderings — a $3,000–$5,000 value, free when you build with us.

Zoning & permits

Site evaluation, zoning review, permit applications, city submissions, and engineering — all handled.

Full construction

Foundation to finishing touches with strict quality control and a dedicated project manager.

Utilities & compliance

Electrical, plumbing, HVAC, and California energy-code compliance — including solar where required.

Planning a bigger project? ADU Construction often pairs with Garage Conversions, Room Additions, or Home Builder — we can scope it all together.

Problems we solve

  • Underused lots and garages storing nothing worth storing
  • ADU projects stuck in permitting for a year
  • Family members who need their own space, close by
  • Mortgages that could use a rent check’s help

Common triggers

  • Parents aging in, or adult kids boomeranging home
  • Rental income that would change the monthly math
  • A neighbor’s ADU that made you look at your own backyard
  • New state ADU laws making the project finally feasible
In detail

What this service covers.

Every scope is different, but a adu construction project with Preferred typically includes each of these.

Detached ADUs

Standalone units up to 1,200 sq ft with private entrance, kitchen, and bath — full independence.

Attached ADUs

Connected to the main home with separate entrance and utilities — up to 50% of the home’s size.

Garage conversions

Existing garages transformed into studios, suites, or rentals — the budget-friendly path.

Junior ADUs

Self-contained units under 500 sq ft inside the existing home — simplified permits, minimal cost.

Above-garage ADUs

Living space built over an existing or new garage — square footage without losing the yard.

Interior conversions

Basements and attics repurposed into self-contained units using existing infrastructure.

Two-story & custom ADUs

Multi-level and fully custom units that maximize smaller lots.

Rental readiness

Separate metering, legal compliance, and finishes that rent quickly and appraise properly.

Where we build

Serving greater Los Angeles.

FAQ

Common questions.

Typically $100,000–$300,000 depending on size, design, and type — roughly $200–$400 per square foot. Garage conversions run $50,000–$150,000 and JADUs as little as $20,000–$50,000. Free consultations give you accurate pricing.
Zoning, construction, plumbing, and electrical permits at minimum. As a licensed ADU contractor we handle all permit approvals and inspections for compliance with local regulations.
Garage conversions run 3–6 months, detached ADUs 6–12 months, attached units 5–10 months. We build a detailed schedule to keep your project on track.
Yes — in most areas ADUs can be legally rented once they meet zoning, occupancy, and rental regulations. We help you navigate the requirements and maximize the investment.
Detached ADUs can generally reach 1,200 sq ft; attached units up to 50% of the primary home; JADUs are capped at 500 sq ft. Setbacks are typically 4 feet. Your free site evaluation confirms what your lot allows.
Get started

Ready to unlock your property’s potential?

Get a free site evaluation and 3D ADU design ($3,000–$5,000 value) — we’ll map what your lot allows and what it would earn.

(818) 312-6622
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