All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.
Mortgage given by usury-based banks is a prohibited transaction that is based on giving a loan for a usurious interest. By virtue of this mortgage, the bank mortgages the house for which the borrower takes the loan until the debt plus the usurious interest are repaid. In case the indebted person is unable to pay off the debt on time, the bank has the right to sell the estate to get its money.
In the 2nd conference on the works of banks held by the Islamic Research Academy, Muslim scholars unanimously issued the following Fatwa:
“Interest on all kinds of loans is prohibited usury whether the loan is used for consumption or production. Usury in these loans is prohibited, regardless whether it is much or little. Giving usurious loans is a prohibited act that is not allowed, either under need or necessity. In the same way, taking usurious loans is also prohibited and it is still a major sin unless there is a necessity to do so. In truth, the responsibility of evaluating necessity lies totally on the shoulder of the person.” [This Fatwa is quoted form the Islamic Fiqh Academy journal]
As such, you are not allowed to take a mortgage, even if the percentage of the usurious interest is very little, as long as you are able to have a house – even through renting and with no unbearable hardship.
For more benefit on the ruling on mortgage, please refer to Fatwa 81377.
Allah knows best.