Money transfers can be done in any way you want. In government institutions, when the sale is made officially, it is asked whether a money agreement has been made. If both parties agree to pay in bitcoin, it's okay. The transaction can be made at the current value of the current bitcoin. The seller of the house can instantly change the amount he wants to any currency he wants.
the biggest problem with this is undoubtedly the volatility of bitcoin. if a person takes 1 BTC = 50,000$ and buys a house that costs 50,000$, the buyer accepts to receive 1 BTC and months later the 1 BTC is worth 25,000$ then this home seller will be at a 50% loss, and the guy who bought a house will have made the best deal of his life, especially if he is a guy who bought bitcoin for the price of 10,000$, honestly this cryptocurrency market is for the smart ones, there will always be people who lost a lot of money if they accept bitcoin as a method of payment. payment in times when the price is too high