DIY Converting a garage to living space is a great way to gain space for that extra guest, or that much needed bathroom. Detailed instructions and floor plan examples. In order to convert a garage to living space first examine some requirements that living space must meet compared to what garages usually have to offer.
Living space is insulated. Many garages have no insulation. You must insulate the garage for it to ever have any usefulness as living space.
Living space has underfloor services such as HVAC duct work, plumbing, and electrical services. Garages typically have slabs that are purposely out of level for drainage reasons. If enough distance exists between the slab and the floor of the existing house, then by all means, a wooden floor system needs to be built above the slab.
Garages have garage doors. When converted, the doors are of no use to an area of living space. Close them in wisely. A poor job hear will result in the appearance of very poor workmanship. If it is a brick house, then remove the bricks to the nearest corners. this is the only way to match them up. If it is siding house, then remove all of the siding to the corners. It is possible to use this space for windows. be very careful here. You are better off to start all over with the exterior; it is not that big of a deal.
This is an idea of what can be done with with a standard 22′ x 22′ garage with 16′ door. It is nothing short of amazing what a new floor and few doors and windows can do!