A Sharia mortgage has a different risk profile for the borrower. You don't own the property up front, and have an option, not an obligation, to transact at a later date, and stamp duty only gets paid once since the law was changed for this in 2003. You may be paying for the ablity to walk away if things get bad. This is why they are more expensive. On a commercial venture the expenses may be taxable, and the speculator buys an investment with no down side. Quite a bit of my understanding of the mechanics above is likely to be wrong! But they do have a different risk profile, and like any mortgage product and variation, one day a bank will offer a loss leader too good to turn down. Can anyone correct my possibly incorrect analysis of these products or add more detail?