Some useful tips based on experience

Ceiling
High ceiling is the best, it gives the house a wide feeling.

Living room
Big window preferable low, but really big one, for view and fresh air.

Toilets
Bathtub - if any, to be jacuzzi shaped, instead of the long one.
Sink - High enough so that you don't have to bend too much when taking wudhu,better still , have a wudhu taking area!
Cupboards - Just one underneath sink will do. Maybe one tall one near a wall mirror for guests stuff, like handtowels, creams, whatever ...

Kitchen
Big! Space! Centre table for work and entertaining, and in a hurry breakfasts. Wide kitchen with easy to clean cabinets.

Rooms
Hotel kind. Something resort like, not too flashy, more woody things. No cupboards in room. Just bed and maybe a nice ming-dynasty like tv rack.

One room for wardrobe only! Yippeeeeeeeeeeee