It will be a little more than that. First of all a 22 million dollar building is zoned commercial obviously, and you will never find a 4% for a commercial mortgage. It will be more like 7 or 8 percent. Also, its amortization wont be 30 years, but more like 10-15. With just the principle payment on a 15 year mortgage at 7% you are looking at a 170k payment per month. Thats with 20% down WITHOUT taxes. Private investors, or Hard money lenders require AT LEAST 30% down, probably more for this size. Im guessing monthly payments would be upwards of 250k with everything included. Thats a lot of dough.