We have a mudroom off of our kitchen, on our main floor (above a full-height basement). Ive stripped the old vinyl flooring off the floor in the mudroom, and would like to raise the floor 4 inches to meet the hardwood floor in the kitchen and probably tile. Is there a convenient way to do this without removing the floor completely and raising it from the basement? i.e. can I build some kind of floor structure on top and put down ply? Its a small area, and currently it is chipboard (under the vinyl) laid down over the rafters. Thanks in advance, all!