window seat Strawbale construction: 3 times the insulation value of a conventional wall; 3 times more fire proof than a conventional home (yes, you read that right!); lessens pollution by using a waste material that normally contributes significantly to the pollution cycle; ideal building system for the owner builder; incredibly sound proof; able to withstand natural disasters
The cheapest way to insulate a building such as a house is when it's under construction and walls and ceilings are open. The cheapest material will depend on how much insulation is needed and where it is installed; exterior walls and attics, for instance, require different types of insulation. The best way to compare costs is with R-value, or heat resistance per square foot.