Attic Insulation

Blown-in fiberglass or cellulose attic insulation costs $1,500-$3,500 for a typical house and pays for itself in energy savings within 2-4 years. At resale, it returns 100%+ because buyers (and their inspectors) check insulation levels, and a home energy audit showing R-49 attic insulation makes the house sellable in any market. It's invisible, unglamorous, and the most cost-effective upgrade you can make. The EPA estimates proper insulation saves 15% on heating and cooling — $200-$600/year in most climates.