Local builder Construction Resources, has built a home that has been independently rated at 350% above the Energy Star standards for energy efficiency. And no it hasn't been done with any fancy new technology, or at least not much. Basically it's just a solidly build home that has been sealed tight and insulated well with the addition of a solar hot water system. Of course, it has a sealed crawl space. Sealing it tight (and this house rated 178% better than Energy Star in the Blower Door test) is all about the details. They've caulked everything including the cabinetry and sub floor.
The walls which are simply framed with 2x6s are insulated for an R21 with fiberglass batts, but the attic has a whopping R-62 from cellulose. And another little detail, there's an R49 hatch cover for the attic stairs, where you'd otherwise have a great big heat loss. Tech Shield sheathing also does a great deal to hold back the heat in the attic.
So, according to the independent raters at Southern Energy Management, the home which is about 2500 square feet will cost about $25 per month for heating and cooling over the year.
Construction Resources' Tom O'Dwyer has shown that attention to detail, good building practices and most of all just caring can do a lot to make homes super energy efficient.