If it is an official government-sponsored student loan your repayments are deducted before you receive your monthly wages, so it is the amount AFTER you have made your payments that is taken into account when the lenders decide how much mortgage to offer you. I got a mortgage at age 24 with about £7K still outstanding in student loans because I was earning enough to cover the payments on the property I wanted, so it is possible but I was obviously limited in what size property i could afford.