Almost every cost associated with green building is higher. I can't even think of anything in green building that's cheaper up front - that's a struggle. But so many of those costs have efficiency statistics compared to conventional building that are no-brainers. Insulation is a great example. With green building, insulation costs more, but it pays for itself in a year or two in the form of much lower energy bills. High efficiency water heaters start paying for themselves as soon as you turn them on. Many times they're paid for in a year or two. Heating systems, windows, roofing and ventilation systems are all examples of high upfront costs that are great investments later on just because of how much energy and money they save. Green builders make their systems airtight, so you don't lose heat or let in too much heat. So all those things combine to make high upfront costs that start to pay for themselves the moment you start using them in your home. Non-toxic paints, though, do not pay for themselves in any really measurable way. Low volatile organic compound (VOC) paints and adhesives reduce the outgassing of toxic chemicals into your house, but that doesn't necessarily pay for itself in a tangible way. Using VOCs really addresses health concerns. They might save you on doctor bills or health insurance, but that's tough to measure. And if you got cancer ten years from now, it would be pretty hard to prove that the outgassing of your carpet glues was what caused your illness. But the high upfront costs of green building overall really can pay for themselves in tangible ways within a few years.
