External wall insulation is the process of adding insulating materials to the outside of a building’s walls, usually with a protective layer of render or cladding. This technique forms an unbroken insulation layer surrounding the structure, which greatly decreases heat loss and enhances energy efficiency. External wall insulation helps to reduce heating and cooling costs by maintaining a more stable internal temperature of the building. Moreover, it improves the look of the structure and offers defense against the elements, reducing the risk of problems like moisture and damage to the building’s framework. This method not just enhances comfort and cuts energy costs but also prolongs the life of the walls in the building.