we've got one and love it
ours was..
ground floor - integral garage, stupidly long hall, small utility room with loo, downstairs room that never really had a purpose other than storing junk
middle floor - lounge, kitchen, bathroom
top floor - three bedrooms
then we re-modelled and now it's...
ground floor - not quite so big integral garage, not quite so long hall, cloakroom (posh name for downstairs loo and sink!) and fabulous kitchen which is huge, has an enourmous table in it and has an extra bit hidden round the corner to act as a utility room (was part of the garage)
middle floor - lounge, study (will have all pcs, homework space etc, currently room full of junk ), bathroom
top floor - three bedrooms
ypou get used to the stairs