thermal envelope

The thermal envelope is the boundary around a building that controls heat flow, including walls, roof, windows, and doors. Its purpose is to keep indoor warmth in during winter and outside heat out during summer, improving energy efficiency and comfort. A well-designed thermal envelope minimizes the need for heating and cooling by reducing unwanted heat transfer, helping save energy and reduce costs. In essence, it's the "insulation shield" that maintains a stable indoor climate by acting as a barrier between the interior and exterior environments.