Construction work is now expected to start later this year with students scheduled to move in on a phased basis over three years from September 2014.
Under plans drawn up by the University of Edinburgh, accommodation for 1,180 postgraduate students will be developed across two sites on either side of Holyrood Road in Edinburgh.
When Balfour Beatty was selected as preferred bidder last year, it was described as a £110m contract. It is now valued at £92m.
Balfour Beatty has a 50-year concession to look after the building, as well as responsibility for designing and building it. Investors were invited to purchase bonds to part-fund the development earlier this month.
The university was advised by law firm Pinsent Masons whose partner Stuart Barr said: "The demand for bonds linked to the project – and the A2 rating applied by Moody's – serve as further evidence that Scotland is seen as a safe haven for investment, and that infrastructure projects remain popular due to the steady returns generated. University accommodation is an asset class which continues to perform well in a market where the pipeline for PPP over the last few years has been relatively sparse."