Garage Conversion Cost: 2026 Price Ranges and Budget Guide

Most garage conversions cost between about $10,000 and $50,000, but the real number depends on one question: are you adding a simple room, or a self-contained suite with a kitchen and bathroom? This Old House puts the range at $9,659 to $51,659, while Angi reports a narrower professional range of $5,996 to $27,348. A fully plumbed garage ADU in Utah sits above both. Our own garage conversion ADU projects run from $60,000 to $120,000.

Below, we explain why the ranges differ so much, what each type of conversion costs, which line items homeowners forget, and what to check with your city before you spend anything.

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TL;DR

National figures for a garage conversion span roughly $9,600 to over $50,000. A basic bonus room or office is at the low end, and a room with plumbing and HVAC is at the high end.
A garage conversion ADU with a kitchen and bathroom is a different project. Our Garage Conversion ADUs run $60,000 to $120,000.
Budget for permits, insulation to current energy code, an electrical panel check and replacement parking. These are the items that most often blow up a budget.
In Utah, cities must allow internal ADUs, but they can still require you to replace the parking you lose.
Expect a conversion to serve your family’s needs rather than pay back at resale, unless it is a permitted, rentable ADU.

What a garage conversion costs in 2026
What drives the price up or down
The costs people forget
Permits and zoning in Utah
A budget worksheet you can use
Is a garage conversion worth it?
Perspective: how we would budget a garage conversion
Working with us in Washington and Iron Counties
FAQ
Sources

What a garage conversion costs in 2026

Published ranges vary because they measure different projects. A guide that averages home offices and guest rooms will produce a lower number than one that includes bathrooms and kitchenettes.

Source	Stated range	What it tells you
This Old House	$9,659 to $51,659	Wide range driven by size, finishes and scope
Angi	$5,996 to $27,348	Professional conversions, driven by garage size and room type
Prestigious Home Builders (our published range)	$60,000 to $120,000	Garage Conversion ADUs, a full dwelling unit

The gap between the third row and the first two is not a contradiction. A guest room or office needs insulation, drywall, flooring, lighting and a way to heat and cool it. An ADU needs all of that plus a kitchen, a bathroom, separate utilities planning, egress and a permit path as a dwelling. Most of the added cost is plumbing, mechanical systems and inspections.

Cost by type of room

Use these as a way to think about scope, not as quotes. Prices for anything with plumbing climb quickly.

Home office, gym or playroom. The simplest scope: framing, insulation, drywall, flooring, electrical and a mini-split or extended HVAC. This sits at the lower end of national ranges.
Bedroom. Same as above, plus egress windows and smoke and carbon monoxide alarms that meet current code. Closets and a bathroom nearby push the cost up.
Primary suite with bathroom. Plumbing is the main driver. If the garage slab has to be cut to run drain lines, expect the budget to move toward the top of the national range. A Reddit thread from a homeowner planning a master bed and bath in a two-car garage shows how often plumbing is the unknown.
Full ADU with kitchen and bath. In our work, this is $60,000 to $120,000 for a garage conversion ADU. Basement ADUs run $80,000 to $150,000 and attached ADUs $120,000 to $200,000, which gives you a useful comparison if you are weighing where to put the unit.

What drives the price up or down

Size and starting condition

A one-car garage is simply less floor area to finish than a two-car. Older garages may have uneven slabs, no insulation, exposed rafters and minimal wiring, all of which add labor before finishes even start.

Plumbing and mechanical systems

Projects that need plumbing and HVAC extensions trend toward the high end of the range, according to This Old House. A bathroom or kitchen should sit as close as possible to existing supply and drain lines. A separate mini-split system is common, because the home’s furnace is rarely sized for added space.

Finishes

Luxury flooring, custom cabinetry and high-end fixtures can push any conversion past typical ranges. Angi notes that plumbing, electrical work and high-end finishes are what raise totals. If you need to trim, finishes are the safest place to do it. Structure, insulation and code items are not.

Your location

Labor, permit fees and material costs vary by region. A California price guide and a Midwest forum thread will not predict a southern Utah bid. Get local numbers before you anchor to a national figure.

The costs people forget

These are the line items that turn a $25,000 plan into a $40,000 invoice.

Energy code compliance

A garage is unconditioned space. Once it becomes living space, it must meet the same requirements as new construction. A Washington State permit tip sheet on garage conversions says the project must meet the same requirements as new construction. That means current insulation levels in walls, floors and roof, compliant windows and appropriate mechanical equipment. Codes differ by state, so check which edition your Utah city has adopted, but plan for insulation that is far beyond what a garage has.

If you are still deciding how to insulate, our guide to garage insulation options explains why sealing air leaks comes first.

Floor and slab work

Garage slabs are often lower than the house floor and slope toward the door. Raising the floor to match the house level, adding a moisture barrier and insulating below the finish floor all add cost. The same tip sheet lists items such as slab and foundation requirements that homeowners do not see until a plan reviewer flags them.

The garage door opening

You will need to frame in the old door opening with a proper insulated wall, a window or siding that matches the house. Doing this poorly is the fastest way to make a conversion look like a conversion.

Electrical panel capacity

Many older homes have 100-amp panels. A builder’s renovation guide warns that a panel like that may not support an ADU, kitchen appliances and HVAC at once, and that a panel upgrade is often needed to pass final inspection. Ask your electrician for a load calculation before you finalize the budget.

Permits and design fees

Thumbtack cites permit costs of roughly $300 to $1,500 depending on the jurisdiction, and Angi suggests budgeting $300 to $1,000. For ADUs, add plan drawings, possible engineering and utility connection or impact fees where a city charges them. Ask your city’s building department for its current fee schedule.

Replacement parking

This is the Utah-specific line item. We cover it next.

Permits and zoning in Utah

No, you should not convert a garage without a permit. Thumbtack notes that unpermitted work can hurt property value and can lead to a requirement to return the space to a garage. It will also complicate a sale, because buyers’ inspectors and lenders look for permits on finished space.

What Utah law says about internal ADUs

Utah’s internal ADU statute, Utah Code 10-9a-530, requires cities to allow internal ADUs, but cities keep authority to require extra parking and to dictate replacement of garage parking that is eliminated. A summary of the 2026 statute says the same: cities may require one additional off-street space for the ADU and may require replacement of converted garage parking. They may also require a rental license and prohibit internal ADUs in a limited share of single-family land.

In practice, that means your budget may need a driveway extension, a carport or a new parking pad. Replacing two garage stalls with concrete and a clear layout is a real cost. If you add wheel stops or low barriers to define the new spaces, a product such as rubber parking bumpers is a minor line item compared with the concrete work itself.

Detached garages are different

Converting a detached garage is treated more strictly than converting an attached one. A Utah state ADU summary shows that some zones apply minimum lot sizes of 12,000 square feet and setbacks that differ from those for the main residence. Lehi’s accessory-use ordinance is an example of a city that allows a detached garage to have an ADU only under listed conditions. Every city writes its own rules, so confirm yours.

For the state-level picture, see our guides on Utah ADU laws and the October 1, 2026 deadline and how big an ADU can be in Utah.

A simple permit path

Call your city’s planning department and ask whether your zone allows an internal or detached ADU, and what parking it requires.
Ask the building department which energy code edition applies and what plan set it needs.
Have drawings made, including floor plan, electrical, plumbing and insulation details.
Submit for permit and pay fees.
Schedule inspections at framing, rough-in, insulation and final.

A budget worksheet you can use

Build your budget in layers, so one surprise does not break it.

Base construction. Framing, insulation, drywall, flooring, doors, windows, paint.
Systems. Electrical, HVAC, and plumbing if you want a bathroom or kitchen.
Code items. Slab leveling, energy compliance, egress, alarms, panel upgrade if needed.
Exterior. Infilling the garage door, siding match, any driveway or parking replacement.
Soft costs. Design, drawings, permits, utility fees.
Contingency. Set aside a cushion for what opens up once walls are open. A garage you have never looked behind is the most likely place to find surprises.

Our garage finishing cost guide is useful if you want a finished garage that is still a garage, and our garage conversion to ADU guide goes deeper on the ADU path.

Is a garage conversion worth it?

It depends on what you want from it. If you need a bedroom, an office or space for a parent or adult child, it solves a real problem without a new foundation or a bigger lot.

For resale, be realistic. The 2025 Zonda Cost vs. Value data, as summarized by a real estate brokerage, shows garage door replacement leading at about 268% return, while interior garage conversions often do not recoup their full costs unless the space is a fully permitted, in-demand ADU. Converting a garage can also remove a feature that many buyers want. A permitted ADU with its own entrance, kitchen and bathroom, on the other hand, can bring rental income or flexible multigenerational living.

Perspective: how we would budget a garage conversion

We build garage conversion ADUs, so we see what separates smooth projects from stressful ones. Most budget trouble starts in three places: parking that the city requires you to replace, an electrical panel that cannot take the new load, and insulation and slab work that nobody priced because the garage “looks fine.” We would rather you find those in a consultation than at a failed inspection.

Our advice is to decide what the space is for before you ask for a number. A guest room and a rentable unit are different projects with different permits, different mechanical systems and different budgets. Once the purpose is clear, a single team that handles design and construction keeps the plan, the drawings and the price aligned. That is why we work with a single point of contact and show you 3D renderings and virtual consultations before construction starts, so you can change a layout on screen rather than in the framing.

And if the numbers say a garage conversion is the wrong move, we will say so. Sometimes a basement ADU or a garage addition is a better fit for the lot.

— Jake

Working with us in Washington and Iron Counties

If you are in Washington or Iron County and want a conversion priced for your garage, our ADU build service covers garage conversion ADUs from $60,000 to $120,000, along with basement and attached options. If your plan is more of a bedroom or family room than a separate unit, our room additions page lists bedroom additions from $25,000 to $75,000. You can also compare Utah ADU costs by type or contact us to start a virtual consultation.

If your plan is instead to build a new garage to replace the one you convert, read our guide to garage construction cost in Utah or garage addition cost.

FAQ

How much does it cost to convert a garage into a bedroom?

A bedroom is on the simpler end of the range because it needs no plumbing, though it needs egress windows, insulation, HVAC and electrical work. National guides place general conversions between about $9,600 and $51,659, so expect a bedroom to land in the lower to middle part of that range. Adding a bathroom moves it higher.

Do I need a permit to convert my garage?

Almost always, yes. Permit fees are commonly $300 to $1,500 depending on where you live. Contact your city’s building department before design starts, because Utah cities set their own parking and zoning rules for ADUs.

Can I convert my garage to an ADU in Utah?

Often you can. State law requires cities to allow internal ADUs, but your city may require replacement parking and set its own conditions, and detached garages face stricter rules. Check with your city’s planning department first, then talk to a builder about the design.

Does a garage conversion add value?

Not reliably. Zonda’s 2025 data shows exterior projects such as garage door replacement far outperforming interior conversions at resale. A permitted ADU that someone can live in or rent is the strongest case for added value.

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