If you buy a house directly with Bitcoin, you will still need to pay taxes. You will need to report your Bitcoins to the IRS or whatever your country has, because you can't hide a house.. they will find you have a house sooner or later. So before you think about it, consider the % of Bitcoin that will go to taxes first, because maybe you don't have enough to buy it.
My idea now is to buy a house the usual way : with some fiat I have aside for a (big) down-payment, and a big fat 25 years mortgage. Then pay off the mortgage every month with fiat made thanks to bitcoin. Inconspicuous, no large transfer of money. Allows to hold onto my BTC which I expect to go up a lot in the future, much more so than the house.