It depends on one thing: whether your neighborhood needs the parking. If it does, a garage conversion can tank your resale value. If it doesn't, you're adding livable square footage for a fraction of what an addition costs. That's the whole decision, and everything below is just the math behind it.
Converting a two-car garage to finished living space runs $15,000–$50,000 depending on scope. A basic bedroom or office conversion — insulation, drywall, flooring, HVAC extension — lands around $15,000–$25,000. Add a bathroom, kitchenette, or a full ADU setup and you're looking at $35,000–$50,000, sometimes more once permits and egress windows enter the picture.
The Math That Makes It Worth It
A two-car garage is roughly 400–500 square feet. In markets where finished living space sells for $200–$400 per square foot, that converted space can add $80,000–$200,000 in appraised value — if buyers value the room more than the parking.
On ROI percentages: a well-done conversion in the right market recovers 60–80% of its cost at resale, and a permitted ADU in a rental-hungry city can recover 100%+ once you factor in rental income. At $1,200–$2,000/month in rent, a $40,000 ADU conversion pays itself back in roughly 2–3 years, then keeps paying.
That's the case for doing it. Cheap square footage, fast payback when rented, and a real bump on the appraisal — provided the parking isn't the sticking point.
Appraisers only credit converted garage space as living area if it's permitted and finished to code. Un-permitted conversions often appraise as zero added value — or worse, as a deduction for the lost garage.— residential appraiser, on why permits decide the ROI
The Catch: When It Flips Negative
The verdict flips the moment parking becomes scarce. In dense urban cores, snowbelt cities, and neighborhoods with no driveways or street parking, removing a garage can knock $10,000–$20,000 off your home's value — buyers walk over it. The same $40,000 you spent 'adding' space becomes a net loss.
Three conditions push you into the red: comparable homes in your area all have garages (yours will look deficient), your climate makes covered parking a hard requirement, or you skip permits and the work reads as un-permitted DIY to any inspector. Any one of these can turn a value-add into a value-drain.
Before you commit, pull comps within a half-mile. If nearly every recent sale kept its garage, that's your market telling you parking is priced in. If converted spaces and ADUs are selling fine, you have your green light.
If the Numbers Work for You
Once you've checked your comps and the math lands on the right side, the next thing that decides your ROI is the quality — and legality — of the actual build. A conversion only holds its value if it's permitted, code-compliant, and finished well enough that an appraiser counts every square foot.
That's where getting the right contractor matters more than shaving a few dollars off the bid. Compare quotes from people who'll pull the permits and stand behind the work, and structure the payment so you're protected until each phase is done right.