IS MY COTTAGE ENERGY EFFICIENT & INSULATED ? A full insulation package is included for the floor, the walls and the ceiling. This also includes a solid double moisture and air vapor barrier in the floors, ceiling and walls. We pride ourselves in using only premium quality energy efficient materials.Our windows and doors are all double pane, insulated with Low E glass. Each cottage is carefully sealed and caulked during the assembly process and the smaller size of the structure, plus the tight and careful construction, ensure that the cottage is very energy efficient. all of our units also come with dual heater/ AC split units 12,000 BTU