It all depends on parental income if you are applying as a supported student. If you are applying independently with no support, the circs are slightly different. You may want to look on the Student Finance part of this site or the Student Finance England or Wales or Scotland or NI websites which have loads of info.
Every country of the UK is different in terms of student finance. Accommodation costs need weighing up very carefully, when you know the amount of Maintenance Loan and parental support you will get. Some London based universities for example are well out of the league of many poorer students. I have seen accommodation costs in London in excess of £10k p/a which is far more than the entire maintenance loan ...let alone taking into account, living costs, travel etc.
Loans and in certain areas like myself in Wales, grants, are paid three times a year in October, January and May so many Uni's offer 3 accommodation installments to coincide with Loan times.
It's not easy and accommodation costs are rising, but work out your parental annual income first and then look at where you stand with loans and what you can get. Some Uni's do scholarships and bursaries too. My older brother won a scholarship for History at Aberystwyth last year by sitting the entrance exams and this is worth an extra £1k p/a for him on top of his loan and grant so well worth looking into.
I must admit I am very glad I live in Wales...our student finance help in grants and tuition fee help too is a great relief, especially as my parents will have 2 of us at Uni next year.