Insulation & Air Sealing
Low-e coatings screen infrared heat from moving through the glass, either inward, outward, or both
Simple upgrades to steps you take anyway can significantly boost the energy performance of a home
The first layer of foam is mostly an insulation layer; the outer layer is the air barrier and drainage plane. This video is about the first layer.
Everything* you need to know about adding insulation to the outside of old homes with cold bones