Home owners often treat insulation as an afterthought but it is arguably the most important building component for boosting efficiency and savings. Yet owners try to go cheap. After all, how sexy is insulation? Insulation isn't cool like geo-thermal or solar systems. You're just stuffing it inside the walls and between the joists where nobody sees it. Who cares? Just put anything in there so at least there's something between the inside and outside, and save a buck while you're at it, right?