What is the best residential roof assembly for the U.S. Desert Southwest, with respect to cost, energy efficiency and embodied energy concerns

The climate is continually changing for the worse as there are poor decisions being made in the rapidly constructed built environment. In an effort to reduce the impact on the built environment, the typical residential roof assemblies that are currently being used in the U.S. desert southwest are not the best for the environment. Through research and simulations, this paper compares several residential roof assemblies to the standard code compliant construction and provides cost breakdowns of simple payback and cost of save energy for each of the simulated systems. A case study was also designed for the U.S. Department of Energy, Race to Zero Student Design Competition using the information of this paper. The case study verified that the results work for the climate and demonstrate that low energy use residential buildings in the U.S. Desert Southwest are possible. The results of this paper will allow designers to work toward the goal of creating net-zero energy housing.