Cellulose is one of the oldest forms of insulating building materials.

It was used as early as 1809 with the construction of the Monticello which used a form of cellulose.

It became the United States primary form of insulation in the 1950’s, due primarily to rising costs of electric heating.

Modern cellulose, made from recycled newspaper, became exceedingly popular in the 1950’s due to the development of a fire retardant that can be used to reduce the risk of fire.

During the 70’s with the onset of the Oil Embargo, as heating fuel prices began to skyrocket and people became much more interested in energy efficiency; cellulose became even more popular.

Today scientists are experimenting with new types of substances known as phase change materials (PCM’s) which have further reduced the risk of fire and decreased the thermal conductivity which in turn increase the R value to better than R-4 per inch.