You can easily build a Styrofoam igloo. How you would do this is with Styrofoam, glue, and a hacksaw or fine-toothed saw. With the saw you will need to cut several large blocks out of the Styrofoam. From these blocks, you should cut several blocks. Each should be slightly smaller than the other so that they can be stacked to make a dome shape. It will take about 4 to 5 layers in order to build the igloo.