No, you don't have to be a Mustafarian lava mite - or whatever the hell the canonical name for those things is - to live in a house made from molten rock. By the time things come together, it has cooled down.
As of now this is only a concept, but it's basically akin to your everyday Jello mold in execution. Giant casting beds (that won't melt, somehow) in the shape of walls and a roof are dug in the path of an active volcano before it erupts. The lava fills them up, then eventually cools and solidifes. Dig those puppies up, and it's insta-houses all around!
"Lava as a material is naturally light and thermally insulating and has the potential to be a strong building block," said [Kieren] Jones, the guy who came up with this notion. With great optimism, he also adds, "The United Nations are currently able to predict with relative accuracy when each Decade Volcano is likely to erupt and determine the direction in which the lava will flow."
Nothing should go wrong with us trying to control natural disasters, right?