I am not sure if this works, you want to borrow Fiat money against Bitcoins. Will you over the bank bitcoins as collateral or the apartment you are buying? If the property is the collateral it might work, because I don't think the bank would accept bitcoins at the moment, the price dropped to much this year. Taking out a loan to buy a property is a good idea if you can afford it. I am assuming you are planning on living in the property yourself, or do you want to rent it out? If you live in it yourself then you need to make sure you have a steady income each months to cover the expenses and the interest payments on the loan. Another factor is that we have very high inflation right now, all the new loans will be much more expensive. And if the loan needs to be refinanced in the future you need to expect much higher payments.