Today, passive solar design is the most commercially mature of all the solar technologies. It can provide up to 70% of a building's energy needs by using sensible design and solar orientation. The cottage uses passive solar energy as a primary space heating resource. The cottage employs the four principles of the natural solar cycle, radiation, retention, storage and circulation. The interior is designed to be only one room deep and therefore directly connected to the sunspace. Top up space heating is via a wood burning stove in the living room.