Design tools that are flexible enough to simulate homes that contain custom designs that harness energy from renewable energy sources, particularly solar energy are rare and usually in the form of black-box software. This thesis presents the simulation of the thermal behavior of a completely self-sufficient 75m 2 home by developing a custom simulation program that incorporates mathematical models of most of the significant energy subsystems of the home. Mathematical models use thermal networks to model heat flow and heat storage. Simulations are performed using transient one-dimensional heat flow models. Simulation and design of a photovoltaic-thermal system is focused on due to the lack of design tools that are able to simulate this emerging technology. Simulations and experiments reveal that an overall yearly solar energy utilization efficiency of approximately between 30%-40% can be achieved by capturing the heat from the solar panels. Simulations also show that with the proper use of thermal storage and motorized shading, the heating load on a typical cold winter night that follows a cold, sunny winter day is only 3 kWh. On a hot, sunny summer day simulations reveal that only 4.5 kWh of cooling is required with the proper use of thermal storage and motorized shading controlled based on room temperature and solar gains. A case study of the 2005 Solar Decathlon Home is presented including preliminary results which are used to verify the software models presented in the thesis