I don't know if this will help you but I ADA compliance varies per state but their latest booklet is available www.ada.com. I recommend getting one of these and making sure your construction team sees the spaceplanning and dimensional needs. This is a very basic answer to your questions because I can't see the dimensions of your existing space, but a simple accessable bathroom only requires a door opening of 3 feet width with 18 inches clear wall space inside the bathroom just inside the doorway on the strike side of the door. This allows for easier circulation as well as accessablilty reaching the light switch(s). And you need a min. 3 foot radius clear space for turning around in a chair.
However, the more space you can build the better because you can add/change equipment on an as needed basis without pre-deciding all your future equipment needs and what the current (equipment dimensions change) sizes are. You may want to make sure the shower stall and floor are at the same level (no stepping up to get in), the light switches and outlets, towel racks, mirrors, items stored, are reachable from a sitting position at the height range using a power chair. Try to make sure the sink has no cabinet underneath (ped. or wall mounted) so pulling up to the sink in a scooter will be easy. Use products with "lever handles" for doors and faucets, install a "hand shower" in tubs and showers. Make sure there is "transfer space" (clear space to assist getting to and from toilet) around the toilet. Consider a jacuzzi tub, they work great for our boys.
Same for bedrooms - build it as large as possible to cover future equipment. Provide a scooter parking stall with outlet. Built in desks or counters need clear space underneath for pulling up in a scooter and wall mounted with adjustable heights. Make sure there is an exit to the outside of the house in case of an emergency or for something nice like enjoying a garden.
The list goes on and on...
let me know if you need any further help
That is so funny. We are just starting to do this to. I got this from someone on this site. It has a list of stuff they did and a wish list. I will attach it. I hope this helps. Also my husband found some things on www.ada.gov he just doesn't know how recent it is. But it gives you some minimums for baths and halls: for turning around and things.
My thoughts...We built a house 3 years ago. Make both rooms as big as you can since you will fill them up. Put a dedicated heater in the bathroom, because getting cold is the biggest objection many guys have to showering. Make sure there are alot of electrical outlets and if possible have them dedicated to a generator feed. We put an door to the out side in Erik's room so that in the case of emergency, we can get him out of the house. Those are the basics. We also made a big equipment closet so we could keep charging chair, manual chair, shower chair etc. behind doors. It works well for us.
We are raising the floor in our house to eliminate steps and are looking at putting laminate flooring (looks like tile) down. However, I was curious on how it holds up to the weight of the wheelchair. Does anyone have input they would like to share?
One year at the PPMD meeting they had a session headed by a DMD father/builder who designed and built a home for his DMD son (last year or the year before). He highly recommended a book on building an accessible house. I cant remember the name of it. Does anyone else remember it?