When I added on a 26x26 I put in all 36 inch doors. Planned out the bathroom with a shower that has a built in seat. Designed bath/utility room 8x14 so a wheelchair could get around easily. Also made a second laundry. Old laundry, which still works,is in the basement.
At the time my mother, who lived in Florida, was in a wheelchair. I would help my sister take care of her, so it was an eye opener how to design a room for a wheelchair.
Hope I never get to that point, but if you live long enough you will.