Why are old houses so hot?
Why are old houses so hot? Many older homes have poor insulation, allowing heat to get into your air-conditioned home. Thermal insulation is most often used to keep a home warm during the winter, but it works for the summer months too.
Why are old houses poorly insulated?
Houses built a hundred and fifty years ago were built out of brick or stone, then had an air space, lath and plaster, often made with horse hair. It had a lousy U-value, or thermal transmittance, the amount of heat that goes through the wall.