 But now with wood still at a very high price for framing lumber, it's actually very cost effective to build insulated concrete form. And what that is, if you're not familiar with it, it's essentially building a house out of Lego blocks that are hollow. These are styrofoam type or expanded polystyrene foam blocks that are hollow in the middle. And after you build the wall and all the walls around the house, you fill it full of concrete.