It depends on the current market conditions and your financial goals. However, as a general rule of thumb, I'd suggest selling enough BTC to cover at least 20-30% of the total cost of the house. This would provide you with some buffer in case the price of Bitcoin drops significantly while you are in the process of buying the house. Additionally, having a diversified portfolio that includes both traditional assets and cryptocurrencies can help mitigate risks associated with volatility in any one asset class.

Won’t have to sell… houses will be priced in sats.