What it costs to build an ADU in Austin
The prices
A Checa ADU starts at $50,000 for the home itself. Once typical site work is added, the all-in range across our ADU models runs from $55,000 to $95,000.
Every one of these is a complete home: kitchen, full bath, HVAC, electrical and plumbing, finished and ready to live in. None of them is a shell.
| Model | The home, from | |||
|---|---|---|---|---|
| The AgaveStudio · 400 sq ft | Studio | 400 sq ft | $50,000$55,000–$75,000 all-in | $55,000 to $75,000 |
| The Sage1 bd · 576 sq ft | 1 bd | 576 sq ft | $55,000$60,000–$80,000 all-in | $60,000 to $80,000 |
| The Mesquite1 bd · 640 sq ft | 1 bd | 640 sq ft | $60,000$65,000–$85,000 all-in | $65,000 to $85,000 |
| The Yaupon1 bd · 784 sq ft | 1 bd | 784 sq ft | $65,000$70,000–$95,000 all-in | $70,000 to $95,000 |
Priced June 2026
What your lot adds on top
The home price is fixed by the model. What varies is your lot, which is why we publish a band rather than a single number: a site allowance of 10% to 35% covers foundation, site work, utility connections and permits.
Five things move that allowance more than anything else, and all five are knowable before you commit: how much clay is in the soil, whether the ground is hydric, how steep the lot is, whether it sits in a flood zone, and whether municipal utilities already reach it.
| Factor | Why it moves the number |
|---|---|
| Soil clay content | High-clay soils shrink and swell with moisture, so they demand a stiffer, more expensive foundation. |
| Hydric ground | Ground that holds water needs drainage work before anything is poured. |
| Slope | A flat pad is cheap. Every degree of grade adds excavation, retaining and drainage. |
| Flood zone | A mapped flood zone can require elevation, which changes the foundation and the insurance. |
| Utility access | Municipal water, sewer and power at the property line are the cheap case. A long private run is not. |
Why an ADU costs more per square foot than a house
A kitchen, a bathroom and a heating system cost roughly the same whether they sit in 400 square feet or 1,100. Spread over a small floor area, that fixed content pushes the per-foot number up.
Across our range the per-foot figure falls from $188 at the top end of the smallest home to $80 at the bottom end of the largest. The home is not getting cheaper to build; the fixed content is getting spread wider.
- How much does an ADU cost in Austin?
- A Checa ADU is $55,000 to $95,000 all-in, depending on the model and your lot. The home itself starts at $50,000; the rest is site work, foundation, utilities and permits.
- Does the ADU price include the foundation?
- Not in the home figure, which is the building itself. Foundation and site work sit in the site allowance, because what your ground demands is a property of your lot, not of the model. The all-in band includes a typical allowance for it.
- How long does an ADU take to build?
- Two to three days on site for our ADU models, because the panels arrive from the factory with windows, doors, wiring and plumbing already in them. Permitting and site preparation happen before that.
What a Checa home costs per square foot
$80 to $188 per square foot all-in, and why the number falls as the home gets bigger.
What site work costs, and what drives it
The 10% to 35% allowance explained: soil, slope, flood zone and utilities.
Exactly what the price includes
Line by line: what is in the home figure, what sits in the site allowance, and what is separate.
What each upgrade actually costs
A second bathroom is $5,400. An extra square foot is $36. The real price of every decision.
What it costs to build a house in Austin
A complete, finished home from $50,000, or $55,000 to $120,000 all-in. What that covers and what land adds.