There are many useful appliances and aids which can be incorporated into a house; these can be a boon to all users and are not necessarily limited to people with special needs or limited mobility. Hafele (amongst others) market special accessories and kits for kitchens which improve storage and accessibility to cupboards etc. Small modifications to your kitchen design can improve its functionality; I'm thinking about things like lever taps ( as found in hospitals), allowing for a wheelchair to sit in under a kitchen sink, planning unit sizes and heights around accessibility, location and provision of sockets, task lighting etc. Door handles, ironmongery, switches and basically anything that requires a manual action should be easy to use (e.g. door knobs, whilst looking good do not function well in this regard, especially for people with arthritis or poor muscle tone). The obvious things like door opening widths, corridor planning and accessible bathrooms are of course vital and these are addressed quite well in Part M of the Building Regulations. New fire regs out this year dictate that a 950mm door will be the norm (overall dimension including frame) so this should be incorporated into drawings now. With regard to plumbing and services I'd suggest that things like main water stop cock should be located and of a type suitable for easy operation- this is important in an emergency. Likewise I think that taps should ideally be fitted with thermostatic balancing vlaves to prevent scalding. Level entry bath or shower rooms are a must or better still a "wet room". Durable and low maintenance finishes are a must. Hope this gives you some ideas.