20 Garage Conversion Statistics: Costs, Added Value, and the ADU Boom (2026)
The verified numbers behind turning a garage into living space in 2026, from what it costs to how much value it adds and why homeowners hire vetted pros.
A garage is one of the cheapest ways to add finished square footage to a home, because the roof, foundation, and walls already exist. The average garage conversion runs about $30,659, a fraction of what a ground-up addition costs, according to This Old House. The numbers below pull together verified 2026 data on what conversions cost, how much space and value they add, how fast the accessory dwelling unit trend is growing, and how homeowners actually use the space. If you are weighing the project, our garage conversion services connect you with vetted pros. Here are 20 statistics that put the decision in context.
Key Takeaways
- A garage conversion averages about $30,659, ranging from roughly $9,659 to $51,659 depending on scope (This Old House).
- A two-car garage adds about 400 to 440 square feet of potential living space, and a single-car garage 200 to 240 (This Old House).
- California homes with an ADU appraised at a median $1,064,000 in 2023, versus $715,000 for homes without one (FHFA).
- 2.8 million ADU permits are tracked in a national permit database, with California accounting for 32% (Shovels).
- Los Angeles County permitted more than 45,000 ADUs in 2023, up from about 9,000 statewide in 2018 (FHFA).
- 71% of consumers are unfamiliar with ADUs, yet 32% of non-owners are interested in adding one (Freddie Mac).
- One in four older homeowners would consider building an ADU, most often to house a loved one who needs care (AARP).
What a garage conversion costs
1. The average garage conversion costs about $30,659
Across project types, a garage conversion averages roughly $30,659, with most jobs falling between about $9,659 and $51,659 depending on finish level and whether you add plumbing, according to This Old House. Because the shell already exists, that is well below the cost of a new ground-up home addition.
2. A home office conversion runs $8,200 to $14,700
The simplest and cheapest conversion is a home office, which runs about $8,200 to $14,700 because it usually needs only insulation, drywall, flooring, and electrical rather than plumbing, per This Old House.
3. A bedroom conversion runs $10,400 to $17,800
Converting a garage into a bedroom costs about $10,400 to $17,800, while a living room comes in around $12,300 to $19,600, according to This Old House. Quality insulation is essential to make the slab-and-block shell comfortable year-round.
4. A full ADU or studio apartment runs $31,500 to $73,200
Adding a kitchen and bathroom to create a studio apartment or accessory dwelling unit is the most expensive path, at about $31,500 to $73,200, because it brings full plumbing, a kitchen, and often a separate entrance, per This Old House.
5. Electrical and plumbing are the biggest add-ons
The line items that swing a budget most are the mechanicals: electrical upgrades run about $1,112 to $7,228 and plumbing $1,500 to $4,000, according to This Old House. These systems almost always require permits and inspection, which is why they belong with a licensed pro.
Source: This Old House.
Added value and square footage
6. A two-car garage adds 400 to 440 square feet
A single-car garage typically offers 200 to 240 square feet of floor area and a two-car garage about 400 to 440, according to This Old House. That is enough finished space for a bedroom suite, an office, or a compact apartment, all of which count toward a home's livable square footage once permitted.
7. California homes with an ADU appraised at a median $1,064,000
Properties with an accessory dwelling unit in California had a median appraised value of about $1,064,000 in 2023, compared with $715,000 for homes without one, a gap of roughly $349,000, per FHFA data. The comparison reflects location and home size as well as the ADU, but the direction is clear: finished, permitted extra space commands a premium.
8. ADU-equipped homes appreciated faster over the decade
From 2013 to 2023, California properties with ADUs appreciated at about 9.34% annually, ahead of the 7.65% for homes without one, according to FHFA. New flooring installation and a clean, code-compliant finish help a converted space appraise at the higher end.
9. ADUs are valued at less than a third of the main home
Freddie Mac research found that ADUs were valued at less than one-third of the price of the traditional primary residences they sit beside, a reminder that the added rentable or usable space comes at a small fraction of a home's total value (Freddie Mac).
Source: FHFA.
The ADU and legal-conversion boom
10. 2.8 million ADU permits are on record nationwide
A national permit database tracks about 2.8 million ADU permits, with California accounting for 32% and Florida 18% of recent activity, according to Shovels. Garage conversions are among the most common ways those units get built, since the structure already stands.
11. First-time ADU listings grew 8.6% a year
Between 2009 and 2019, the number of first-time ADU listings grew by an average of 8.6% year over year, per Freddie Mac research. That steady climb reflects both new construction and conversions of existing garages, basements, and attics.
12. Los Angeles County permitted 45,000-plus ADUs in a single year
Los Angeles County alone permitted more than 45,000 ADUs in 2023, up from roughly 9,000 permitted statewide across California in 2018, according to FHFA data. Statewide reforms that legalized more conversions drove the surge.
13. ADU appraisals nearly tripled at their peak
California ADU appraisals rose from 3,463 in 2013 to a peak of 9,246 in 2021, per FHFA, a sign of how quickly financing and refinancing tied to ADUs scaled up as more homeowners added legal units.
14. ADUs went from 1.9% to 3.0% of appraisals
The share of California appraisals involving an ADU climbed from 1.9% in 2013 to 3.0% in 2022, according to FHFA. A rising share of the housing stock now includes a legal second unit, often a converted garage.
Source: Shovels.
How homeowners use the space
15. Housing guests and renting are the top reasons
Among homeowners interested in an ADU, 37% cited hosting visitors, 33% renting to long-term tenants, and 21% short-term vacation rentals, according to a Freddie Mac survey. A converted garage can serve any of these without expanding the home's footprint.
16. 55% want space for a loved one who needs care
In AARP's national survey, the leading reason older homeowners would build an ADU was to provide space for a loved one who needs care or a place to live (55%), followed by a place for family or friends to stay (52%), per AARP. Multigenerational living is a major driver of garage conversions.
17. Living rooms and gyms are common no-plumbing conversions
Not every conversion needs a kitchen or bath. A living room conversion runs about $12,300 to $19,600 and a home gym about $8,700 to $15,900, according to This Old House, keeping costs down since they skip plumbing. These simpler projects still add usable, conditioned space.
Who hires a pro and pulls permits
18. 71% of consumers are unfamiliar with ADUs
Despite the boom, 71% of consumers said they were unfamiliar with accessory dwelling units, even as 32% of non-owners expressed interest in having one, according to Freddie Mac. The knowledge gap is one reason many homeowners lean on a pro to navigate rules and permits.
19. One in four older homeowners would consider an ADU
About one in four older homeowners have built or would consider building an ADU on their property, based on AARP's 2024 survey of more than 3,000 adults, per AARP. As that interest converts to projects, permitted, professionally finished conversions are what hold their value.
20. About 89% of new homes come with a garage to convert
In 2024, 65% of newly completed single-family homes had a two-car garage, 15% a three-car, and 9% a one-car, meaning roughly 89% shipped with a garage, according to NAHB analysis of Census data. That vast existing supply of garages is the raw material for future conversions. Our financing options can help spread out the cost.
Source: Freddie Mac.
What this means for homeowners
- A garage conversion is one of the lowest-cost ways to add finished space, averaging about $30,659 versus far more for a ground-up addition, because the shell already exists.
- The project you choose drives the price. A no-plumbing office or gym stays under $15,000, while a full ADU with a kitchen and bath can top $70,000.
- Permitted, code-compliant space adds real value. California homes with an ADU appraised roughly $349,000 higher than those without, and they appreciated faster over the decade.
- The ADU trend is large and growing, with millions of permits on record, so a legal conversion also fits a proven, financeable category of home improvement.
- Pro House Maintenance matches you with vetted, licensed and insured pros and provides free fixed-price estimates. Request an estimate when you are ready to turn your garage into living space.
Frequently Asked Questions
How much does it cost to convert a garage in 2026?
A garage conversion averages about $30,659 nationwide, with most projects landing between roughly $9,659 and $51,659, according to This Old House. A simple home office conversion can run $8,200 to $14,700, while a full studio apartment or ADU with a kitchen and bath ranges from about $31,500 to $73,200. Pro House Maintenance matches you with vetted, licensed and insured pros and gives free fixed-price estimates so you know the number before work begins.
Does converting a garage add value to your home?
It can. In California, homes with an accessory dwelling unit had a median appraised value of about $1,064,000 in 2023 versus $715,000 for homes without one, per FHFA data, and ADU-equipped properties appreciated faster over the prior decade. A garage conversion adds finished, heated square footage, which is what appraisers and buyers pay for. The quality of the finish and whether the work was permitted both affect how much value you capture.
How much living space does a garage conversion add?
A single-car garage typically offers 200 to 240 square feet, and a two-car garage runs about 400 to 440 square feet, according to This Old House. That is enough for a bedroom and bath, a home office, or a compact studio apartment. Insulation, flooring, electrical, and HVAC all have to be brought up to living-space standards, which is where most of the budget goes.
Do you need a permit to convert a garage?
Almost always. Turning a garage into conditioned living space triggers building, electrical, and often plumbing permits, and converting it into a legal accessory dwelling unit adds zoning review. Los Angeles County alone permitted more than 45,000 ADUs in 2023, per FHFA figures, up from about 9,000 statewide in 2018. A vetted local pro handles the permit process and inspections so the added space is legal and insurable.
Should I hire a pro or do a garage conversion myself?
Electrical work on a conversion can run $1,112 to $7,228 and plumbing $1,500 to $4,000, per This Old House, and both usually require permits and inspection. Getting the work wrong can void the added value and create safety and insurance problems. Pro House Maintenance provides free fixed-price estimates from vetted, licensed and insured pros so the finished space passes inspection and holds its value.