For some reason, mushrooms have spawned more than their fair share of puns. As a kid I learned that they’re all fun-guys, and that the only rooms you can’t enter in a house are mushrooms. The last one might not work these days, as entire buildings are now being made of fungus.
Given that mold inside our homes can make us ill, you wouldn’t think that being surrounded by the stuff would be a great idea. But just like so many other things in life, “it depends.” As a building material, fungus is cheap, ubiquitous, and a renewable resource. But that’s not the best part. By dry weight, walls made of fungus are stronger than concrete and have better insulation value than polyurethane foam. They are weather-proof, practically non-combustible, and oddly enough, resist getting moldy.