How to Remodel Bi-Level Garages

Decide how you want to remodel the bilevel garage -- for a children's playroom, an office, an expanded family room or another bedroom. Sketch a floor plan on graph paper and design any new wall treatments, such as opening a space for a window or an outside door. Determine how to cover the garage door opening and how to side the replacement wall there.

Empty the garage and clean the floor of any oil or other dirt. Disconnect the garage door from any opening devices and remove the door from its rough frame; have help for this, as doors are both unwieldy and heavy. Use a screw gun and pry bar to remove the door. Take off any 2-by-6-inch rough door framing if you plan to install a 2-by-4-inch stud wall; most garage doors have a 2-by-6 frame set into a two-by-four-framed opening.

Build a replacement wall on the garage floor. Cut two-by-fours with a circular saw for top and bottom plates to fit inside the rough opening and nail up a rectangle with two-by-four end studs, using 16d framing nails and a hammer. Square the frame by measuring corner to corner with a tape measure and adjusting the frame until the diagonals are equal. Add inside studs with centers 16 inches apart.

Frame any door or window opening inside the new wall with a 2-by-6-inch top header horizontally across the top of the opening. Frame between the header and the bottom plate for a door, or add a horizontal sill of doubled two-by-fours for a window, with short studs cut to fit vertically in those gaps. Secure any frames with short studs at top and bottom.

Raise the wall in place, set it plumb with a level and nail it to the floor with concrete nails and to the old garage door framing on sides and top with framing nails. Take off any door opening apparatus or other installations in the garage ceiling. Leave lighting intact, although you will need to replace fixtures when finishing the space.

Staple fiberglass batt insulation between studs on all walls with a construction stapler. Install drywall on the ceiling and any walls not already covered. Fasten panels to ceiling joists and wall studs with drywall screws. Seal the screw tops and drywall joints with joint compound and drywall tape on seams and corners. Lay down vinyl tile, carpet or other chosen floor covering; this will vary with the type of material selected.

Install prehung windows or doors in the new walls. Add baseboard and window and door trim to match the rest of the house. Replace the old house entry door with a conventional interior door to match other doors in the house. Put exterior siding to match the existing house on the outside of the new wall.