The study looked at how changing the angle of south-facing windows on a building in Shanghai can affect its energy use. By using a computer program called Ecotect, researchers modeled a building to see how adjusting the window angle could help save energy. They found that choosing the right slope angle for these windows could lead to lower energy consumption. This means that simply changing how the windows are installed could help save energy in buildings, especially in a place like Shanghai where summers are hot and winters are cold.