Hi, it depends on whether you can do the work yourself or need to hire it done, also the size of the existing rooms and whether you need to knock out walls to make them larger. Generally speaking, the first thing you need to consider is entry, do you have room for a ramp or do you need a lift. If you have an attached garage (which really is a must) can you enter the house without steps? Once in, doorways should be at least 32", preferably 36" wide. Hard surface flooring is so much easier to roll on and easier to clean wheelchair tracks. Most bathrooms need to be enlarged to accommodate a wheelchair. You need a 5' area to turn around in. Also, you need to have room around the stool (no walls) to be able to use it. And the walls need to be reinforced wherever grab bars are installed. You need to consider the bathing area, will the wheelchair occupant transfer to a shower chair in a tub or do you need to redo an area for a roll in shower. The lavatory should be a simple counter with knee panel, or a wall hung lav so they can roll under. Considering all this, it is probably going to have to be a comple tear down and redo in the bathroom, and that can get expensive. In the kitchen it is nice to have the kitchen sink adapted so they can roll under. A piece of counter, lowered, is ideal for working at, or even eating a simple meal. I have more suggestions if you would like, my husband became paralyzed in 2001 and we decided we needed to build a one level ranch, instead of remodel our 1908 bungalow. Hope this helps.