There are numerous issues that need to be considered when adapting a home for a disabled person. A lot of people need to be involved such as architects, designers and occupational therapists.
Enough space for the owner/occupant to manoeuvre his/her wheelchair; creating an open plan layout so there are no doorways to negotiate; installing a non-slip floor, a wet room-style bathroom and a rise-and-fall hob in the kitchen. Wheelchair users must be able to get their knees under a hob and sink so rise-and-fall worktops are key. Also, the oven trays need to be on telescopic runners so they come out further and do not tip. Induction hobs are safer than gas; and instant hot water taps better than kettles. Worktops with waterfall edges are best for preventing spillages.
Alter the height of electrical switches so you can reach them and install an electrically-operated window in the bathroom.
Install a video entry device on the front door.
Move the Gas & Electricity meters outside so they can be easily accessed without disturbing you or the owner/occupant when the energy company comes to read the meter.
Install or build ramps to enable the owner/occupant to get out into the garden and into the street.