I am currently looking to buy a home built in 2005 that originally had a provision for an over garage bonus room in the plans, however the current owner at the time the home was built elected not to add the room. He advises that the builder at the time did try to get him to go ahead an put in place the structural support so that the room could be completed in the future, but he elected not to spend the money. The garage is a three car, side load that is approximately 25 deep by 40 wide and the area that would have housed the stairwell from inside the home to the room was completed as a closet, so the area for the stairs is in place. I believe that the existing structure over the garage are 2 x 10's spanning the 25' width, but do not know the spacing. I have been informed that the structural support can be "retro-fit" without requiring any support posts or anything of the like in the garage, but am wondering exactly how this could be done and what the cost would be. Any help?