Igloo means house in the Eskimo or Inuit language. In the Inuit societies it has come to mean a snow house and it has come to be known in the rest of the world. A snow house is where Inuit used to live in the winter years, at least those who did not build sod and stone houses. Inuit today no longer live in igloos. They live in central heated wooden houses.
Inuit still build igloos though, especially the hunters. Igloos are still used but mostly in hunting expeditions. They are very handy because snow is abundant and other building material like trees are not in the arctic territories of the Inuit.
Location as in real estate is very important, especially for long term stay overs. Igloos used in hunting, the location is less important but there are a few things to consider. The snow bank where the igloo will be built is important. It was to be of consistent snow, non layered and of good depth.
Non layered because the layers can break during handling. A good depth because the snow blocks must be of consistent quality. Consistent in quality because snow takes on characteristics like fine powder, powder, lightly packed, packed, dense, and crystallized. Of these characteristics 'packed' is the most desirable.
Location can be very important. The igloo should have a good snowbank. The location is preferable on a lee of a hill, but not a lee hill due to the threat of an avalanche. It should also be relatively exposed as a strong blizzard can move lots of snow. A strong blizzard may even cover over an igloo structure making the access of oxygen difficult. People have been known to asphyxiate in their igloos while asleep when their igloo have been covered under a snowbank.
Once a favorable snowbank has been identified, a cut is made into the ground. Most igloo builders make two cuts into the ground, just to open the building area. The third cut can be the first block. Cut rectangular snow blocks about 10-12 inches wide by 2 feet deep and 3 feet 6 inches long. All blocks should be uniform. Depending on the size of your igloo, you should need about 30 to 50 blocks.
Once you have cut the blocks, determine the diameter of your igloo. 10 to 12 feet in diameter is a good size to practice with and it can accommodate you and friend easily. Mark your diameter parameters by staking a wood or pole into the ground and tie a rope around the pole. Determine the radius you will work with. Five feet for a 10 foot diameter for instance. Tie the other end of the rope to a sharp object and you are ready to mark the ground for your parameter.
Place you blocks side by side, so that one supports the other. Make your snow blocks incline slightly. The blocks should not be at a 90 degree angle but about 80 or less degrees. Put loose snow under the blocks to support the blocks. Also fill in the gaps between the two supporting blocks with loose snow. The blocks should be firm with no movement at all. Continue along the marked parameter until you have a full circle.
Once you have achieved a full circle, then you have to grade the first snow wall. If you are left handed person make your grade go down toward your right. Make it an easy and even grade. If you are right handed person, make your grade go down toward the left. When you start building up again, you will be working toward the hand you favor for cutting. Your grade should end at the base of the snow wall and you should have a 90 degrees up to the last snow block. Take a new snow block and place it at where you cutting stopped and right at the 90 degree. This is your supporting snow block.
Each snow block will be build succeeding the one you just had placed. Fill each gap between the snow blocks with loose snow and pack them hard. No snow block should be left loose. Continue and your dome will begin to form. Incline further in as you get higher up. When you reach the ceiling, your snow blocks will have to be cut to measure. You will do this by eye until you finally place the king block and the you have an igloo.
First time igloo builders tend to build tall. Seasoned builders built nice round domes not too high.
Inuit used to life in such structures in minus 3 Celsius comfort. They were so used to it, they could relax as though they were on the beach at Miami. Shirtless and happy but don't try this. If you are not acclimatized to such conditions, you could suffer hypothermia.