Older homes are usually well thought out in terms of natural cooling and heating. Being that many of these homes were built in an era where HVAC systems didn't

Older homes are usually well thought out in terms of natural cooling and heating. Being that many of these homes were built in an era where HVAC systems didn't exist, they can stay remarkably cool in the summer, and warm in the winter. They designed the homes to have proper airflow throughout the house (and underneath the house), and of course, shade from trees. So while their energy efficiency rating may be lower -- in how it can retain the heating or cooling put out by the HVAC, in practice, you don't use your AC or Heat as much as you would in a newer home (which for some reason new home builders seem hellbent on eliminating all trees, and placing the entire home in direct sunlight) My house was built in 1927, and it stays ~75-78 even on a hot summer day, and due to the much thicker materials used, doesn't bottom out past 60 in the winter.