In recent years there has been increased attention in the effect of attics on the energy use of a house. At the same time, interest has developed in adding increased insulation and low emittance surfaces to reduce the heat transer between the attic and the house. Ducts are often placed in attics and exchange heat and air (through leaks) with the attic environment.

Because of a lack of a reliable attic model, a project was initiated to develop an attic model that would accurately predict ceiling heat flows under both summer and winter conditions. The goal was to develop a model that could be interfaced with a building energy program.