The footprint is about 500 sq ft. Bathroom, kitchen and main room on insulated slab. There is about 150 sq ft of loft space. The only HVAC is a small supplemental 'suitcase' unit by Panasonic. Last time I checked in with the owner, they had not had to turn it on. The walls and roof have ridiculous R values. Laundry is a stackable in the bathroom.