The full cost of a PhD Award normally consists of tuition fees, stipend,
and additional programme costs which for overseas studentships are
currently (for the 2014/2015 Session):

Tuition Fees: £16,550 x 3 = £49,650
Stipend (EPSRC Minimum Rate): £13,726 x3 = £41,178
Additional Programme Costs: £1,000 x 3 = £3,000

Total average studentship for an overseas student = £93,828

However -- it should be noted that tuition fees are subject to annual
review and increase by the University which may increase during the
lifetime of the studentship. Any increases are payable to the University
and minimum stipend increases by EPSRC would be due to the student.

We expect the accommodation and subsistence to come from the stipend
(which is a reasonable rate for students to survive in the UK), so do
not have specific costings for accommodation and subsistence and only
the items above are included in studentship offers.  The International
Office web page provides estimated living costs which is here in case
its helpful:
http://www.ed.ac.uk/studying/international/finance/cost-of-living