The earliest form of insulation was during the Middle Ages, when the walls of homes were stuffed with mud and straw to keep out the cold.

In the mid-1970s, home improvement companies traded asbestos insulation for fiberglass insulation after finding out the harmful effects asbestos has on lungs.

Fiberglass was invented when a young researcher named Dale Kleist attempted to create a vacuum-tight seal between two pieces of glass and a high-pressure jet of air shot through and turned them into fibers.

Today, an un-insulated home can lose up to 60% of its energy through walls and the ceiling.

Insulation is measured using an “R-value,” which refers to its resistance to heat flow. The higher the R-value, the better it will insulate.