What Types of ADUs Can a Builder Construct?

4-minute read

Monday, August 4, 2025

Accessory dwelling units (ADUs) are smaller homes or apartments built on the same lot as a primary house. AARP describes an ADU as a self-contained living space with its own kitchen or kitchenette, bathroom, and sleeping area (AARP’s ADU definition).

In Texas, the right ADU plan depends on your city rules and your lot layout. Below are the common ADU categories builders construct, including options often recommended by ADU Builders in Austin.

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Quick answer: the main ADU types builders construct

What counts as an ADU in Texas

Detached ADUs

Attached ADUs

Garage conversions and garage apartments

Interior conversions

Junior-style units

Permitting and plan review basics in Texas

Call to action: talk through your lot and options with a Texas design-build team

Frequently Asked Questions

Quick answer: the main ADU types builders construct

Detached ADU: a separate unit that does not share walls with the main house.

Attached ADU: an addition connected to the primary house that functions as its own living unit.

Garage conversion ADU: an existing garage converted into living space.

Interior conversion ADU: part of the existing home rebuilt into a separate unit (a wing, ground-floor area, or basement where basements exist).

Junior-style unit (JADU-like): a smaller unit created inside the main home using an existing room footprint and a compact kitchen setup.

What counts as an ADU in Texas

An ADU is not just “extra space.” Many local departments treat an ADU as a second “dwelling unit,” meaning the space supports independent day-to-day living. HUD’s housing glossary defines a dwelling unit as a single unit that provides complete, independent living facilities (HUD housing glossary).

Cities can add details. Austin’s ADU guidance says a structure is treated as a dwelling unit if it includes a habitable space, a full bathroom, and a sink or dishwasher outside the bathroom (City of Austin ADU guidance). If your plan meets that definition, you should plan for permits and inspections.

Texas law can influence local limits (see the bill text for Texas SB 673). Verify what applies to your address before finalizing drawings.

Detached ADUs

A detached ADU is a stand-alone unit on your property. Homeowners often choose this option for more privacy and separation of entrances.

Planning usually comes down to placement and utility routing.

Attached ADUs

An attached ADU shares at least one wall with your home, usually as a side or rear addition. This can be a solid fit on tighter lots typically because you are building off the existing structure.

Your builder will plan the structural tie-in, the entry location, and the interior layout so the unit feels separate and comfortable.

Garage conversions and garage apartments

Garage ADUs usually happen in two ways: converting an existing garage, or building a new unit above or beside a garage.

Garages were not built as living space, so builders focus on light, ventilation, insulation, and plumbing routes.

Interior conversions

Interior conversion ADUs use existing space inside the house. This route can work if you have a layout that can be separated into a second unit.

The big question is whether the space can function like its own unit with an entry plan, a kitchen area, and code-ready safety features.

Junior-style units

A junior-style unit is a smaller interior option. Homeowners often reuse an existing bedroom area and add a small kitchen setup.

Because “JADU” is not used the same way everywhere, confirm how your local department classifies this type of project.

Permitting and plan review basics in Texas

Permitting is local, and steps can vary by city. A good starting point is your city’s ADU permitting page, which lists what the department expects for an application. San Antonio provides an ADU permit overview that explains the permit pathway and what applicants should prepare (City of San Antonio ADU permits).

Most projects follow a similar flow: confirm eligibility, submit plans for review, and complete inspections.

Call to action: talk through your lot and options with a Texas design-build team

If you want clear answers on what your property can support, we can help you compare these ADU types, match them to your lot, and guide the permitting and build steps from start to finish.

Book a free phone or Zoom consultation here: ADU builders in Austin.

Frequently Asked Questions

1) What is the difference between a detached and attached ADU?

A detached ADU is a separate structure on your lot, while an attached ADU shares a wall with the main home. The right choice usually depends on your yard space and where an entry can fit.

2) Can a garage be converted into an ADU?

Often, yes, but the finished space still needs to meet your city’s requirements for a dwelling unit. A builder can help you confirm whether the layout supports safe exits, light, and utilities.

3) Do ADUs always need a full kitchen?

Many ADUs include a kitchen or kitchenette, but expectations can depend on local definitions. If you want a smaller setup, ask your local department how it classifies kitchen features for your project type.

4) Are basements common for ADUs in Texas?

Basements exist in some Texas homes, but they are not common in many neighborhoods. If your home has one, plan for extra attention to access, moisture protection, and light.