Draw up plans for your wardrobe or find blueprints on the Internet, at home improvement stores or at the library.
Locate electrical wiring sources in the wall before you start construction if you plan to install interior lighting in the closet. Mark the area with tape or pencil.
Use a pencil or masking tape to mark the locations of the wardrobe's two sidewalls and closet entry wall. Construction pros recommend making the closet at least 28 inches deep to hold standard wardrobe items.
Construct side walls of 2-by-4 boards in either of two ways: (a) frame up the wardrobe's side walls on the floor, then raise them into position for anchoring to the wall or (b) build the side wall frames directly onto the wall. Use more 2-by-4s to close in the three walls.
Mark the center of the wardrobe. To be certain everything is correctly lined up, hang a plumb bob from the ceiling marks to match up with parameter lines on the floor.
Nail 2-by-4s to existing flooring or subflooring and to the ceiling if the wardrobe is to have a finished interior.
Create a door frame on the front of the wardrobe using additional 2-by-4s.
Finish the interior of the wardrobe by tacking and taping precut sheets of drywall to the side and front walls and the ceiling. Cut out the section of drywall covering the electrical power source on the back wall. If a ceiling light is to be installed, cut a section from the ceiling drywall to bring the wiring into the closet.
Install a door. If you choose a sliding or bi-fold door(s), fasten tracks to the top and bottom of the opening before positioning the door(s) on the track. A standard prehung door will require hinges and hardware for installation.
Finish the exterior of the wardrobe with drywall or sand and finish the wood walls. Tape the seams before painting.
Determine the hanging mix of the items the wardrobe is slated to hold. Coats and dresses require more height than short garments like blouses, slacks, jackets and shirts. Install the main clothing rod by marking side walls, then attaching pole sockets to both sides. Insert the rod. Consider installing a center bracket to prevent a long clothing pole from sagging.
Frame up interior shelving units if desired. Cut 2-by-4s into sections to create vertical braces. Add brackets at uniform intervals and slide precut shelves into the unit. If drawers are to be installed, nail frames into place before sliding drawers into the housing. Install the lighting fixture.