2. Cost to Convert a Garage Into a Living Space or Room

Living Space/ Family Room

Turning your garage into a family room can average anywhere between $5,000 and $10,000, depending on whether you need to add a window or door. By law, your family room needs at least one window big enough to use as an emergency exit. Installing insulation, drywall, flooring and HVAC make up the rest of the major costs of this type of project.

a. Apartment or Guest House

A full-scale apartment or guest house is the most expensive garage retrofit, costing on average between $15,000 to $30,000. You'll need to make all the upgrades mentioned for a family room, along with adding a separate bath and kitchen. This can entail jackhammering concrete to run plumbing and sewer lines, adding a gas line or a 220 outlet for the stove, installing a water heater and addressing ventilation over the stove and in the bathroom.

Don't forget to add the cost of an exterior door to your budget, which can provide an attractive private enterance to your new space.

b. Bedroom or Suite

The cost of a bedroom or master suite depends on your choices. At a minimum, you need at least one window, insulation, drywall, trim, flooring, heat and air, lighting and a closet. If you're adding the master bath, factor in plumbing, a second window, insulation, drywall, flooring, lighting, plumbing, shower, tub, toilet, sink, faucets, cabinetry, tile and finishes. Dreaming of a steam shower or a garden tub? You’ll pay an additional $2,650 to $6,050 in costs for a steam shower.

c. Bathroom

The cost to convert an existing space into a bathroom begins at $5,000. High-end renovations could cost as much as $35,000. Your contractor needs to review the space to determine how to cost-effectively add sewer and plumbing lines. Factor in the costs of insulation, drywall, flooring, lighting, plumbing, shower, tub, toilet, sink, faucets, cabinetry, tile and finishes to get a realistic estimate.

d. Kitchen

Adding a kitchen costs at least $5,000 but can go well over $65,000 depending on the design, finishes and appliances you select. Factor in the basics, such as electrical wiring, plumbing, lighting, insulation, drywall, trim and flooring. This job could require rerouting gas and water lines, providing drain lines for the sink and dishwasher, relocating the washer and dryer and adding outlets powerful enough to run large appliances. Your contractor must address ventilation requirements for the stove, which can add cost. Functional items such as cabinets, a pantry, countertops and other work or storage spaces need to be budgeted as well.

Check out our guide on the cost of new appliances.

e. Office or Work Space

The home office will cost at least $5,000, making it one of the more affordable options when it comes to converting your garage into living space. Like a bedroom, a home office needs all the basic amenities, such as finished walls and ceiling, flooring and lights. It also needs HVAC and a window.

This room may also require additional outlets that let you connect computers, printers and charging stations. You'll need internet access and a high-speed connection, as well as lots of storage and organization options. Map out where the furniture and electronics will be placed in this room to make sure your electrical plan addresses how you will use the space.

f. Granny Flat

Adding a granny flat, also known as an accessory apartment or in-law suite, will cost you nearly the same as adding a guest house, at a range between $15,000 and $30,000. You'll need at least a full bath and kitchenette on top of living and sleeping spaces. You'll need heat and air, windows and a private entrance.

g. Utility Room

For a garage-to-utility-room conversion, budget at least $6,000 for appliances, a utility sink, and space for sorting, folding and hanging laundry. A new utility room in place of an old garage brings convenience into your life, especially if you've spent years dragging loads of laundry up and down the stairs. This conversion will cost a bit more due to the addition of plumbing, but it'll be worth it.

h. Renovation Cost Factors to Consider

by Lux Renovations, LLC., Canton, MA. Garage conversion costs in Boston average $11,200.

As you move from the planning stage of your conversion toward execution, remember that doing the job well will add value to your home, while cutting corners may subtract value. Keep these considerations in mind and ask your contractor about each one that's relevant to your renovation goals:

• Building permits cost: $450-$2,250
• Insulation costs: $$0.30-$2 per board foot
• Hanging drywall costs: $1,000-$2,900
• Installing windows costs: $300-$1,200 each
• Installing an egress window costs: $2,600-$5,300. You will need at least one egress window if you want to list the space as a bedroom.
• Adding ducts and vents costs: $475-$2,100
• Electrical outlets cost: $75-$500 each
• Adding plumbing costs: $375-$1,900
• Hiring an interior designer or decorator costs: $2,000-$13,000

3. Cost to Finish a Garage

The cost to finish a garage is often less than the cost of a remodel, coming in at an average of about $5,000. Finishes should factor high on your list of materials before you begin your garage conversion. The answers to the following questions will go far in determining your budget. Low-end finishes will save you big bucks at the time of renovation, but high-end finishes will help recoup your ROI when it comes time to sell.

• Will you use tile or vinyl flooring?
• Will countertops be composite or granite?
• Drywall or paneling?
• Wood cabinetry, veneer or aluminum?

4. Single vs. Two-Car Garage Conversion Cost

The cost to convert a two-car garage to an equipped living space averages $21,000 to $30,000 but can get much higher, depending on the features included. Custom structures, like adding a loft, can raise the price to as high as $50,000. A double garage runs about 22-feet wide by 20-feet deep.

The average size of a single garage is roughly 12-feet wide by 20-feet deep and will generally cost less to renovate, depending on the space and finished state of the garage.

5. Does Converting a Garage Add Value?

If you're planning to maximize the space, make changes and add useful features that are likely to appeal to a majority of homeowners. Done right, your renovation can be a worthwhile investment when it comes to resale value. Remember: The quality of the work matters, especially if you’re planning a major change such as converting the garage into a bedroom. Trading your garage space for a poorly insulated “bedroom” with no windows and the garage door intact won’t do much to boost resale value.

The work you have done must be permitted, it must be professional and it must increase your home’s functionality and appeal. Weigh what you’re planning to spend against the expected increase in resale value to get your return-on-investment (ROI) figure. A well-done garage conversion to living space can give you up to an 80% ROI.