The building envelope is the physical barrier between the interior and exterior of a building. It includes walls, roofs, windows, doors, and façades, and plays a critical role in energy efficiency, weather resistance, and occupant comfort.

Façade engineering ensures that the external face of a building is not only visually striking but also safe, durable, and sustainable. Through structural analysis, thermal modelling, and material selection, façades are designed to withstand environmental loads while minimising energy use.

Typical façade materials include glass, aluminium, stone, precast concrete, terracotta, and high-performance cladding systems. The choice of material affects aesthetics, performance, cost, and long-term maintenance.

A well-designed façade controls heat gain, heat loss, and solar shading. By integrating insulation, high-performance glazing, and passive design strategies, buildings can significantly reduce energy demand while improving occupant comfort.