My first house was in the midwest, built around 1920, and had plaster walls with no insulation. It was only around 1400 sqft, but we did have (natgas) heating b

My first house was in the midwest, built around 1920, and had plaster walls with no insulation. It was only around 1400 sqft, but we did have (natgas) heating bills in that range ($600-$700/mo December through February).