The right insulation will keep your home comfy and your energy costs low. Here’s how to calculate how much you need and what kind to buy. Adding insulation can be a low-cost way to cut energy bills.

Q: Help! My home feels cold in the winter and too hot in the summer, and I think I need to add insulation. But how much insulation do I need? A: According to the Insulation Institute, around 90 ...