What is the most common type of insulation material used in buildings?

The most common type of insulation material used in buildings is fiberglass insulation. This type of insulation is made of tiny glass fibers and is used in both residential and commercial buildings. Fiberglass insulation is relatively inexpensive, easy to install, and provides excellent thermal insulation. It can be used in a variety of applications including walls, attics, and floors.

Other common types of insulation materials used in buildings include mineral wool, cellulose, and spray foam insulation. Mineral wool is made from natural rock or recycled slag and is often used in commercial buildings. Cellulose insulation is made from recycled paper and is used in walls and attics. Spray foam insulation is a newer type of insulation that is sprayed into walls and attics. It provides excellent thermal insulation and can also act as an air barrier, helping to reduce energy costs.