Building energy models were created to assess how well a building design uses energy and to find ways to save energy and money. A new method was developed to make a building energy model based on the physics of how energy moves in buildings. The model's performance was tested by looking at how it responds to changes. The model showed how much energy the HVAC and lighting systems used each day, week, and month. This method can help designers see how well a system works before making changes, making it easier and cheaper to fix problems and make things more stable.