Admittedly a tad late in the season for this, but for us still sweltering through temps over 30oC, it is a welcome diversion. Igloos, aside from being white, are obviously very green. No forests are plundered or no open cut mines or quarries required to provide the raw materials. And after its useful life, the shelter simply reverts to water. But it does take a modicum of skill to construct an igloo. As Tipster Rick U. points out in his Instructable picture show, Quinzees are much more freeform. Just shovel a heap of snow into a big pile, let it freeze solid and dig a hole into the centre of the mound. Presto. Shelter from the storm. And much warmer than outside air temperatures. Rick made his on a lake and had a blue hued wall, with a solar lit green floor, arranged by directing light from the lake up into the Quinzee. Alas they don’t work everywhere. Down here in Australia, for example, our snow is generally too heavy for effective Quinzee construction. But Igloos and Quinzees do show that zero impact habitation is possible. ::Quinzee Instructable.