ADU and garage apartment cost · Fort Worth
How much does an ADU cost in Fort Worth?
A garage apartment or ADU with us runs $40,000 to $280,000, construction plus our fee, before permits and contingency.
Or call or text (817) 631-9803
What it costs with us
Garage apartment cost in Fort Worth, from a conversion to a new build
Converting the garage you already have sits at the $40,000 end. A new building out back, with its own foundation, reaches $280,000.
Three ways to build one, in order from the low end of the range to the top.
$40,000 to $280,000-
Convert the garage you have
The foundation, walls and roof are already standing, so the money goes into making it a place to live.
A Mistletoe Heights garage we turned into a home office and guest house, with a new bathroom. See the project
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Build over the garage
The cars keep their garage, and the apartment goes on top. Built on the garage you already have, it starts with an engineer.
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A new building out back
Its own foundation, its own walls and roof, and every utility line run out to it from the house.
A backyard casita we built behind an Arlington Heights bungalow. See the project
$150 to $350 a square foot
Both figures are construction plus our fee, billed Cost Plus: you see what the materials and labor really cost, and our markup is listed on top of them.
Want the whole service, from the lot check to the keys? See garage apartments in Fort Worth.
Garage apartment or addition
Why a garage apartment costs less than an addition and takes longer
Our garage apartments top out at $280,000 and take 6 to 9 months. Our additions reach $420,000 and take 3 to 9 months. That looks backwards until you see what each one starts from.
| Item | Garage apartment or ADU | Home addition |
|---|---|---|
| With us | $40,000 to $280,000 | $60,000 to $420,000 |
| A square foot | $150 to $350 | $175 to $400 |
| Time | 6 to 9 months | 3 to 9 months |
| Fort Worth permit fees | $800 to $2,500 | $1,200 to $3,500 |
An addition borrows from the house it joins: the foundation it ties into, the roof it extends, the water, power and gas already a few feet away. A garage apartment stands on its own. It gets its own foundation, its own utility runs dug out from the house, and its own permit, and none of it borrows from the house.
Adding onto the house instead? Here’s what a home addition costs in Fort Worth.
What moves the price
What moves a garage apartment from $40,000 to $280,000
Whether you convert or build new sets where you start. Then the kitchen and bath, the foundation, and how far the utilities have to travel decide whether you pay nearer $150 or nearer $350 a square foot.
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Convert or build new
A conversion keeps the slab, the walls and the roof that are already there. That is why it’s the least expensive way to get real living space out back.
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A kitchen and bath from nothing
A garage has never had water lines, a drain or the power a kitchen needs. Running all three in, and upgrading the panel to carry them, is the biggest line on most conversions.
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The foundation, on a new building
A new building needs a new slab or pier-and-beam under it, and on a ground-up build that is one of the largest single costs.
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Where the trucks can reach
How far the water, sewer and power have to run from the house, and whether a concrete truck can get to the back of your lot.
The City’s rules
Three City of Fort Worth rules that change what an ADU costs
In Fort Worth an ADU is an accessory building under the zoning ordinance. Three of its lines shape the budget before anyone picks a finish.
- Its utilities come from the house.
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“Accessory structures that connect to utilities such as water, electric and gas must receive service from meters serving the primary structure.”
§5.300(b) For your budget: everything runs out from the house’s meters, so the distance from the house to the ADU shows up in the price.
City of Fort Worth Zoning Ordinance §5.300, read October 29, 2026
- It can’t outgrow the house.
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“Accessory structures shall not be a greater square footage than the primary structure.”
§5.300(c) “May not exceed the height of the primary”
§5.301(c)(2) For your budget: the house you already have sets the largest ADU you can build.
City of Fort Worth Zoning Ordinance §5.300 and §5.301, read October 29, 2026
- Building on the garage you have takes an engineer.
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“Engineering is required for the following: … Structures built over existing foundations”
the City’s accessory checklist For your budget: building on top of the garage you have starts with an engineer.
City of Fort Worth, “Submittal Requirements for New Residential Accessories”, ADD 08/29/2024
It also has to sit inside the house’s side and rear setbacks, and its roof counts toward your lot coverage. Setback requirements in Fort Worth. For every rule on an ADU, and what the 2025 Texas laws did and didn’t change, read Fort Worth ADU rules.
Budgeting
What to budget on top of the build
Beside our range, a garage apartment needs three more lines on your budget: permits, a contingency and your plans.
- Fort Worth permit fees:
- $800 to $2,500
- A contingency:
- 10 to 15 percent
- More on a conversion, where demolition turns up the surprises.
- Your plans:
- A separate drafting fee
- Our drafting team draws your garage apartment, and plans run $2,000 to $16,000 as a separate fee from building it.
Timeline
Plan on 6 to 9 months with us. You get a real schedule before work starts. How long a remodel or an addition takes in Fort Worth
Best Home Builder & Remodeler
Fort Worth MagazineFort Worth Chamber Small Business of the Year4.7 stars from 91 Google reviews as of September 2026
How much does it cost to convert a garage into an apartment?
Conversions sit toward the low end of our $40,000 to $280,000 range, construction plus our fee, before permits and contingency, because the slab, walls and roof are already there. The kitchen and bathroom are usually the largest line, since a garage has never had the plumbing or the power for them. Plan on a 10 to 15 percent contingency, and more on a conversion, where demolition turns up the surprises.
How much does an apartment over a garage cost?
It’s priced inside the same $40,000 to $280,000 range. Building on top of the garage you have starts with an engineer, because the City of Fort Worth asks for engineering on structures built over existing foundations. Building a new garage with the apartment above means a new foundation, which is one of the biggest costs on any ground-up build.
How much does an ADU cost per square foot in Fort Worth?
With us, $150 to $350 a square foot, construction plus our fee, before permits and contingency. Converting a garage that already has its slab, walls and roof is the least expensive way to get that square footage. Whether there’s a kitchen and bath, the foundation and how far the utilities run decide the rest.
What do permits cost for an ADU in Fort Worth?
Fort Worth permit fees on our garage apartments run $800 to $2,500. Your plans are a separate drafting fee, and a contingency of 10 to 15 percent goes on top of the build.
Can I rent out an ADU in Fort Worth to pay for it?
Check your zoning first. In a one-family district, Fort Worth’s zoning ordinance says an ADU “may be used only as an accessory dwelling unit and may not be used as a separate independent residence.” Ask what that means for your lot before you plan around rent. Fort Worth ADU rules
Does a garage apartment add value to my house?
It adds usable square footage and an income option where your zoning allows one, which is not the same thing as a guaranteed return. We are a brokerage as well as a builder, so our agents can tell you what it would add to a house on your block.
How to get a garage apartment estimate
After the first walkthrough you get an estimate. Once the design is done, you get a detailed budget.
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Meet Up.
A designer and a builder walk your lot and your garage with you at no charge, check what the City allows on it, and give you an estimate.
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Team Up.
Our drafting team draws it, we bring in a licensed outside engineer where the City asks for one, and your detailed budget comes from those drawings.
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Glasses Up.
We build it, you watch the budget as it moves, and you get the key to a small complete home on your own lot.
Know what your garage apartment costs before you draw it
Your lot, your garage and the house in front of it decide most of the number. A design that doesn’t fit the lot is money spent on paper, so have us walk all three before you pay for one.
Or call or text (817) 631-9803