The building envelope refers to the physical barrier between the interior and exterior of a structure. It includes elements such as walls, roofs, windows, and doors, which work together to protect the building from weather elements like rain, wind, and temperature changes. A well-designed building envelope enhances energy efficiency and comfort for occupants. In addition to providing protection, the building envelope plays a crucial role in controlling air and moisture flow. Proper insulation and sealing help maintain indoor air quality and reduce energy costs. Overall, the building envelope is essential for the durability and performance of any structure.