Growing up a had a friend that grew up in a supper insulated house (it was blown insulation for walls). They had electric heat. They built a greenhouse on the

Growing up a had a friend that grew up in a supper insulated house (it was blown insulation for walls). They had electric heat. They built a greenhouse on the side of the house that provided a lot of the heat in the winter. Because the trees where leafy it was shaded in the summer and they used fans to move the heat it worked out well. They sold the house and it was torn down, but it was An interesting structure.