There have actually been people who sold and bought houses for BTC and other crypto's.
I recall seeing one house in Italy being offered for Dash on some other forum, and someone apparently bought that less than a month ago.
On bitify and another bitcoin auction place I've seen houses for sale priced in BTC and another cryptocurrency, as well, one of those was in the US, the other house was either in Germany or Austria, I forgot which.

And seriously, as someone else already pointed out with an example of a gold ring... it doesn't matter which form of trade is agreed upon; fiat money, Adam West's worn socks from his last time in the Batman suit, six camels and a goat, a rare misprinted stamp on which Queen Elizabeth has a third boob... bottom line, as long as buyer and seller agree on the exchange of the house for -whatever trade item was offered/wanted in return- and all the paperwork involved is done, it's a valid deal.