<prompt> Human: Hi PF!In the near future I will be in the market to purchase my first home. My younger sister is interesting in purchasing one together with me, though she doesnt currently have as much liquid funds as I do. As such, I am happy to put down the money for the deposit on the mortgage, and then we would split the mortgage payments 50:50. The main question that has been of great discussion is, say the property is sold in 20 years time, how would the funds for the sale be split? Do the calculations needs to take in to account the time value of money? Or say I pay a deposit of 10, this would mean I would own 55 10 45 once the loan is paid off?  <response>: You should not buy real estate with someone you are not married to. 