The Myth of U-Value

For over forty years the public has believed that insulation behaves similarly to piling blankets on a bed, ie. if you double the thickness of insulation you double the energy savings. Unfortunately this is not true, but this widespread myth has led to well meaning legislators introducing building codes with increased wall thicknesses and higher building costs in the mistaken belief that lower U, K or lambda value in Europe (or higher R value in North America) is all that is required to solve the energy crisis.