There are alternatives to mortgages, and there is more than one provider in the market who can help you to purchase land and property. Explore the possibilities. Having said that, it can sometimes be difficult to obtain a mortgage in an Islamic bank, which can have difficult procedures and requirements. If this is the case, there can be exceptions, within reason. Yes, you do need to have a roof above your head, but if you need two bedrooms you don't need to find a mortgage for a five bedroom house.
The European fatwa council issued a fatwa on this before the Islamic Bank of Britain started providing house finance: if you have no alternative, then you are allowed to get a mortgage as a condition of necessity, but it's important to discuss this with a qualified person in this area i.e. a scholar.