The EcoTerra solar house was analyzed to see how much energy it uses and how it can be more efficient. The house has a special roof that collects both heat and electricity from the sun. The heat is used to warm water, heat the floors, and dry clothes. The researchers looked at all the data collected since the house was built to figure out how to make it even better. They found ways to improve the control system and make the house use even less energy. The study shows that with the right changes, houses like EcoTerra can reach net-zero energy use.