That's excellent!!
I used to make them when I was young - but I used a different method:
Roll some f*ckoff big snowballs all together (usually about 4) and fill in the gaps with loose snow which is then compacted. Thus you now have a 'snow hill'. Then smply dig out the inner of the igloo with trowels/spade etc. and hollow it out to the required size.
Used to take ages but was a great laugh. Also, the removed snow can be made into snowballs for the inevitable fight with friends/siblings from your newly built 'den'.
Hope the snow is still there tomnight so I can get out with the eldest and have a laugh.

