What is the ruling on real estate financing in which the commission is 15%, the repayment period is 10 years, and the condition for financing is mortgaging the property?

It is forbidden to borrow with usury if the borrower has to return more than the principal to the lender. There are permissible forms of real estate financing if they adhere to Sharia controls, including: financing through deferred sale (بيع آجل), financing through Murabaha for a term (مرابحة لأجل), financing through Istisna' (استصناع), and parallel Istisna' (استصناع موازي).