The home that seemed so roomy when you bought it can begin to feel cramped as your family grows and changes over time. If moving or adding-on are not options, you may be able to turn an attic, basement, or garage into living space. A garage conversion is cheaper and less intrusive than an addition, and there is less bureaucratic red tape. Much of the work can be done by a do-it-yourself homeowner armed with the proper tools and knowledge.
Contact your local zoning board or building department for building code information and any needed permits.
Decide what the garage will be used for, and design the layout. You can sketch it out on paper, use a computer-aided design (CAD) program, or hire an architect. One benefit to converting a garage is that it's an open space with fairly high ceilings, which gives you a lot of choices for its new purpose. Some options include a bedroom, workshop, home gym, media room, art studio, office, or game room. Depending on the size of the garage, you may be able to split it into two separate rooms.
Decide which parts of the project you will do yourself, and which you'll hire a professional contractor to do. For certain parts of the project, such as electrical; plumbing; and heating, ventilation, and air conditioning (HVAC) work, local laws may require the job be done by licensed or certified professionals. After you have decided on the parts of the project you will contract out, shop around for prices, and research the contractors you are considering. Check with your local Better Business Bureau, consumer websites, and the state or local agency responsible for oversight. Ask the contractor for references. Ask your friends or family for their recommendations and warnings. The contractors will be in your home, and you will be paying them a good amount of money, so check them out carefully.
Begin with the electrical, plumbing and HVAC work needed. Hire a professional to perform any work you don't have the skills to do yourself, or that laws forbid you to do. The intended use of the converted garage will factor into what type of plumbing, electrical and HVAC work needs to be done. If you're creating a bedroom, you'll need to connect into your home's HVAC system or install its own system, while that wouldn't be necessary if your goal is to have a workshop (although it could make working conditions more tolerable). For the bedroom conversion, you'll probably want to install a bathroom, especially if it's going to be a suite for in-laws. That means you'll need to install plumbing lines and fixtures. A media room wouldn't necessarily require plumbing work, although it'd be nice, but you'd need electrical additions and a cable or satellite hookup.
Inspect the floor of the garage. Patch any small cracks by properly filling them with patching compound. If the cracks are large, have a professional inspect the floor. Large cracks in the floor, or places where part of the floor is higher than other parts, can be a sign of a foundation problem, which will be easier and less expensive to remedy now rather than later, as the problem can worsen over time.
Decide what to do with the garage door. Again you have several options, depending on your intended use of the converted space. Removing the garage door and finishing the wall where the door currently is can be very expensive, as you need to frame and build an exterior wall, insulate it, and apply brick or siding that matches the area surrounding the door. If the siding or brick is several years old, you may not be able to match the materials. Even if you do, the new section may stand out against the older, more worn section of the wall. Another option is installing a sliding glass door or French doors in place of the old garage door. You can also leave the garage door intact, remove the interior hardware, and build an interior wall over it.
Finish any unfinished garage walls and add walls as needed. To add walls such as bathroom walls, contruct the wall frames in accordance with local building codes and nail them to sill plates (pressure-treated boards bolted to the floor). Apply insulation to the gaps between the wall studs, and cover the bare studs with drywall.
Install any new doors and windows. You have many options. You can install French or sliding glass doors in place of the old garage doors, or build a wall over that area that contains a window. You may also want to replace any existing doors and windows. Over time, the seals wear out and become less energy-efficient, and they can look drab and dirty compared with the rest of your new room. When selecting the doors and windows, check to see if you can get tax credits for installing ones that are energy-efficient. While it might cost you slightly more up front, between the tax credits and the energy savings it can save money in the long run.
Paint the ceiling and walls. Begin by applying two coats of primer to the drywall, followed by the top coat of paint.
Install the new flooring. You can use tile, carpet or hardwood flooring. Again, the type of flooring you install depends on the intended use of the room. A carpet would be ideal for a bedroom, but you'd want to install tile, and not carpet, in a workshop.
Always follow local building codes when doing a project such as this. You can be fined and forced to pay for expensive repairs for failing to follow the codes.