Geodesic domes had a brief surge of popularity in the 1950s, but they still aren’t a usual shape for a home. This is a pity, because they’re really exceptional for eco-friendly purposes. The Bear Creek Dome in North Branch, Minnesota has all the usual benefits of a geodesic dome, including increased strength while only using 40% of the lumber of a usual home, and natural heating and cooling. Bear creek dome ups the ante by incorporating 16 inches of insulation and triple-pane windows to prevent energy loss. Despite outside temperatures of over 90 degrees, inside the dome the owners enjoyed a balmy low 70s – without any air conditioning or power use. Their yearly heating costs are less than $900, despite the bitterly old Minnesota winters.