Developers want to transform the A-listed Calton Hill site into a £75 million luxury hotel, but their controversial vision was rejected by councillors last year by eight votes to seven.
After vowing they would not “give up at the first hurdle”, they lodged a last-ditch appeal in March, and on Wednesday next week the Scottish Government will begin its hearing into the controversial scheme.
An alternative proposal to convert the landmark – which dates back to 1829 – into a new home for St Mary’s Music School is expected to go before councillors in mid August.
Earlier this year, it emerged the hotel proposals were one of several city projects criticised by Unesco advisers. The world heritage body said it was “deeply worried” over the quality of new developments in the Capital.
Designed by Thomas Hamilton in the early 19th century, the neoclassical Royal High building has lain neglected for almost 50 years after the former boys’ school moved to Barnton.
Adam Wilkinson, director of Edinburgh World Heritage, branded the latest appeal “a waste of everyone’s time”.
He said: “Edinburgh council rejected the hotel application on a broad range of measures following a very thorough debate, both in public and on the floor of the development sub-committee.
“The development team must know that their chances of gaining consent through the appeal process are limited, especially when there is a financially viable and fully funded alternative scheme for the site, in the form of the music school proposals, that is sensitive to its history and heritage.
“It’s a waste of everyone’s time and money to put us through the inquiry process, which requires a great deal of preparation and hard work for all parties.”
But supporters of the hotel point to the extra jobs, investment and high-spending tourists it could attract to the city.
Scottish Government reporters Scott Ferrie and Dannie Onn will examine the appeal by Duddingston House Properties and the Urbanist Group.
A “pre-examination meeting” on July 20 will lay out the contentious issues – such as the scheme’s impact on Edinburgh’s built heritage – as well as the likely duration of the inquiry. Three weeks have already been earmarked by the reporters in which to hear representations, running from September 19 to October 3.
Procedures for how evidence will be heard will be decided next week, as well as the venue for the inquiry – and the need for any site inspections.
Duddingston House Properties and the Urbanist Group could not be reached for comment.