Downstairs...

The basement... Bedroom 4 (the guest room) in the basement, currently housing the computer bits and bobs.
Washing machine and drier, not my domain really.
Scary looking heating system.
Family/play room...
Very clever air-exchanger - sort of climate control for a house, sucks stale air out of the place and replaces it with nice fresh stuff from outside!
Assorted cupboards and an extra bathroom also down here.