The sunroom has large windows facing south to let the low winter sun inside, but to keep the high summer sun outside. The winter sun warms the earthen floor and plasters, known as thermal mass. When the sunroom french doors are open into the main room, the warmth spreads to the entire house. The house has no central heating. At night, the french doors are closed to insulate the main house. In the far side of the sunroom is an aviary for my cockatiels--I found the first one when I was walking in the desert and could not get used to keeping him in a small cage. The ceiling is covered with reed fencing, found in the garden department at any Home Depot.