6 ways to use your kid's old bedroom

Build an entertainment cave

If your home is on a slab, your extra bedroom could be the entertainment cave you’ve always craved but never had room for until now. One caveat: This plan can backfire. Make the room too fabulous, and your child might prefer living there to living in the dorm or in a crummy first apartment.

Start with a flat-screen television (careful not to go too big or watching it will be like sitting in the front row of the movie theater). Add surround sound and room-darkening drapes.

Buy the comfiest sofa bed you can find to accommodate your kid if he does decide to come home sometime.

Estimated cost: $3,000 for surround sound, 50-inch flat screen and a queen sleeper sofa.