A light-gauge steel ADU frame standing on a Southern California backyard lot

Single-Family ADUs

An ADU built around your life, on your lot.

Rental income, room for family, a home office, or simply more value in your property. We design and build single-family ADUs across Southern California, on your property, permitted and constructed start to finish by our own crews.

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01Why build an ADU

One structure, a handful of good reasons to build it.

Every homeowner's reason is a little different. These are the ones we hear most, on almost every property we evaluate.

Rental income

A backyard ADU is rentable square footage on land you already own, a straightforward way to add income without buying more property.

Multigenerational living & aging in place

Keep parents, adult kids, or a caregiver close by, each with a private front door, without sharing a roof or giving up anyone's independence.

A home office or studio

A quiet, dedicated workspace separate from the main house. No commute, and no meetings at the kitchen table.

Property value

Many owners see a meaningful increase in property value after adding an ADU, though it depends on your market and the unit itself. We won't promise you a specific number nobody can guarantee.

02Your options

Every real way to add an ADU to a single-family lot.

"ADU" covers more than one kind of project. Here is what we actually design and build, and where each one tends to make sense.

Detached ADU

A freestanding new structure in the backyard. Up to 1,200 square feet statewide by default, the most common choice when you have yard space to work with.

Attached ADU

Built onto your existing house, sharing a wall. Often a better fit on narrower lots where a fully detached structure would not clear the setbacks.

Garage conversion

Your existing garage becomes a finished, livable unit. Often the fastest and least expensive path, since the structure is already standing.

Above-garage ADU

A new unit built over an existing or new garage, adding living space without spending yard footprint on the ground floor.

Interior conversion

A spare room, basement, or other existing space inside the main house, converted into a self-contained unit with its own entrance.

Junior ADU (JADU)

A small unit of up to 500 square feet, built inside the walls of your existing house or attached garage. One allowed per lot.

What the law actually allows

California's Accessory Dwelling Unit Law (Gov. Code §66310 et seq.) requires most single-family lots to allow up to 3 accessory units total: one conversion ADU from existing space, one Junior ADU, and one new-construction detached ADU. Not every lot fits all three, and every city runs its own review process, but that is the baseline the state sets. There is no owner-occupancy requirement to build or rent out an ADU. The one exception is a JADU that shares plumbing with the main house, which does require the owner to live on site.

See the full legal detail on California ADU law

03How it works

Design, permit, build. We carry the hard parts.

We run feasibility, design, permitting, and construction as one team, so you are not stitching together separate vendors yourself. Because panelized walls are engineered off-site while permitting and site work move in parallel, this approach is often significantly faster than a fully stick-framed build. Every city moves at its own pace on permitting, so once we know your lot and your jurisdiction, we will give you a real timeline, not a guess.

See the Full Process

01
Evaluate
A free site and zoning review. We tell you honestly what fits your lot.
02
Design & permit
Engineering, drawings, and city submittals, managed for you end to end.
03
Build on your property
Our own crews construct and finish the unit on your lot, inspected at every stage.

04Layouts to start from

Pre-engineered layouts, or a fully custom design.

Every layout below is pre-engineered panelized light-gauge steel, designed by our sister company LyteMods and built on your property by our own crews. Sizes and finishes can be adjusted to your lot, and if none of these fit, we design a custom ADU from scratch.

Browse all layouts

Micro Mods

The Nook

U250-01

Studio · 1 Bath · 240 sq ft

Our smallest complete ADU, a studio in 240 square feet.

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Single Family

The Casita

S500-11

1 Bed · 1 Bath · 500 sq ft

A true one-bedroom ADU in a compact, gracious 500 square feet.

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Single Family

The Gem

S1200-32

3 Bed · 2 Bath · 1,245 sq ft

Our most-built single-family layout, 3 beds, 2 baths, 1,245 sq ft.

View Layout

Single Family

The Grand

S1200-42

4 Bed · 2 Bath · 1,200 sq ft

A full four-bedroom ADU at the statewide 1,200 sq ft size cap.

View Layout

What owners say

ADUs people are proud to own.

Real Google reviews from ADU Concepts clients across Los Angeles.

5.023 Google reviews

“After meeting with three different contractors in Tarzana and giving each careful thought, I decided to go with ADU Concepts for our ADU project. David was very competitive on price. He really listened to my overall ideas and then worked out a plan that included all the little details I mentioned. I couldn't be happier with how everything turned out!!”

Caroline P.

Tarzana, CA · June 2026

Google

“ADU Concepts built a detached ADU on our Calabasas property and did a fantastic job. They guided us through permitting, construction, and inspections while keeping the project moving smoothly. The finished space looks amazing.”

Michael S.

Calabasas, CA · June 2026

Google

“Highly recommended. The quality of the workmanship was outstanding and the finished results of our ADU exceeded the expectations. David and the team were attentive, organized, and quick to address any questions or concerns we had along the way. Their team was respectful of our home and kept the area clean daily.”

Amber K.

Los Angeles, CA · May 2026

Google

Wrong hub?

Adding units to a rental or investment property instead?

If you already own an apartment building, duplex, or other multifamily property, a different set of rules applies, and the opportunity is bigger: detached ADUs, interior conversions, and carport conversions across the whole property. That is a specialty of ours.

See the Multifamily & Densification Hub

05Common questions

Single-family ADU questions, answered straight.

How many ADUs can I add to a single-family lot?

California's Accessory Dwelling Unit Law requires most cities to allow up to 3 accessory units on a single-family lot: one ADU converted from existing space, one Junior ADU, and one new-construction detached ADU. Not every lot fits all three, but that is the baseline the state sets.

Do I have to live on the property to build or rent out an ADU?

No. State law permanently removed any owner-occupancy requirement for ADUs. The one exception is a Junior ADU that shares plumbing with the main house, which does require the owner to live on site.

Can I just convert my garage instead of building something new?

Yes. A garage conversion counts as your one conversion ADU under state law, and it is often the fastest, least expensive path to a rentable unit, since the structure already exists.

How long does permitting take?

Cities must decide a complete ADU application within 60 days or it is automatically approved, after a shorter completeness check up front. We manage that process and know how each city we build in actually runs it.

More questions? Visit our full FAQ page.

Let's find out what fits your lot.

Tell us about your property and what you are hoping to get out of an ADU. We will follow up honestly: what fits, what it costs, and what it takes to permit.

Get a Free Evaluation Or call (818) 962-6900

Licensed California General Contractor, CSLB #1018294. A TESH Group company.