This is dRMM’s model of the sliding house - a rather better version than my primitive version shown previously on these pages.
Position 1 is shown left - the one we would use most of the time. The main house is covered, the terrace beyond the house (shown with a swimming pool) is open and there is a glasshouse standing about not doing very much at all beyond that. In this position we might use the glasshouse to shelter less hardy plants (such as citrus trees). The entrance to the house would be on the side shown here but most of the windows are to the other side overlooking the rest of the plot. The outer envelope is the weatherproof and waterproof section so it has all the window glass and the door (which therefore move as the envelope moves).
The red block is the (immobile) guest annex and the other block is the (also immobile) garage and workshop.