I wish I could increase the insulation capabilities of my house. My house is literally stucco on the outside, a paper vapor barrier, and then it's the studs and drywall of my walls. I have no sheathing in between my studs and drywall, so I have massive air flow. I would literally have to rip down all my walls and add a layer of sheathing in order to stop air flow and add insulation, and would cost ~$50,000. Better to just turn on my furnace during the winter months and spend $300/month for 4 months a year.