What is the primary purpose of insulation in walls?

The primary purpose of insulation in walls is to decrease energy consumption. Insulation acts as a barrier to heat flow, helping to maintain a consistent indoor temperature by keeping heated air inside during the winter and blocking out excessive heat during the summer. This thermal resistance reduces the need for heating and cooling systems to work harder, thereby leading to lower energy costs. By effectively managing the flow of heat, proper insulation can significantly improve a building's energy efficiency and contribute to overall comfort within the space.

Although insulation can have secondary benefits, such as enhancing acoustics by reducing sound transmission through walls, improving fire resistance (in the case of certain fire-rated insulation materials), and indirectly supporting structural integrity through the prevention of moisture buildup that can lead to structural damage, its primary function centers on thermal performance and energy conservation.