Usher Hall's glass extension opens after along overture

A CONTROVERSIAL extension to Edinburgh's main concert hall will finally open to the public this week – as it emerged that the cost of a 13-year revamp is set to top £40 million.

The public will get to see a host of new facilities at the Usher Hall on Thursday, after almost three years of construction work ended this month.

Bosses say they expect the glass-covered wing – which will boast a new caf-bar, box office, hospitality facilities, offices and workshop spaces – to help reinforce the venue's position as one of the world's leading concert halls.

However, managers admit that work on a flagship "culture quarter" outside the hall will continue until just weeks before the Edinburgh International Festival.

The final bill for the project – triggered by the collapse of part of the auditorium ceiling after a concert in April 1996 – will not be known until later this year, but will be at least 39.5m. Previous estimates suggested the total cost of the project would be 35m.

The latest costing does not include compensation payments made to organisations which have been unable to use the building, including the RSNO.

The eventual cost of the overhaul will be more than three times original estimates. The total price-tag is also 11m more than when it was supposedly "pegged" by council officials in 2006. But the project has been dogged by problems, mainly to do with the rock formations beneath the A-listed venue, which have seen it slip well over a year behind schedule.

In 2007, the council admitted it had been forced to find about 2m of savings for the project in order to bring it on budget.

At the time, it decided to take the culture quarter, which is currently estimated to be costing 3.95m, out of the project budget and finish it off once work on the main building was completed. Builders moved in to start those improvements – insisted on by the council as part of the planning permission for the revamp – back in October. They are not expected to be complete until at least June.

After the collapse of an early lottery bid to fund a 13m revamp of the building, an initial overhaul of the auditorium, which dates back to 1914, was completed in 2000. It took another six years to get the funding for a second phase, which has seen outdated backstage areas, and ageing toilet and bar facilities overhauled, along with the creation of the extension next to the Royal Lyceum Theatre.

An Usher Hall spokeswoman said: "The final phase to landscape and pedestrianise the area surrounding the hall is under way. The work will enhance the feel of the area as 'an arts quarter', creating a more attractive space."

A council spokeswoman said details of an official opening gala would be announced this week.