It could have been an exclusive venue where celebs and the glitterati could hob-nob far from the rabble. But any plans rock band U2 might have to party in private in their rooftop bar overlooking Dublin have been dashed.

The Republic's planning board, An Bord Pleanala, has granted planning permission for a controversial redevelopment of the Clarence Hotel on the Dublin quays, but included an unusual condition that the public must have access to the fabled 'sky bar' which is an intrinsic part of the plans.

Although the band had not sought to refuse permission to the public, it is the second time in recent months authorities have felt obliged to compel hostelries to open their doors to the public. In May, the High Court ruled that a members-only club on St Stephen's Green could operate a VIP system, but would not be allowed to refuse entry to the general public.

Yesterday's decision means that U2 members Bono and The Edge, along with property developer Paddy McKillen, can begin work on the €150m project to quadruple the size of the building and transform it into a nine-storey, 140-bedroom, five-star hotel, designed by architect Norman Foster.

"We are delighted that An Bord Pleanala has given us the green light for Norman Foster's design for The Clarence," the owners said in a statement yesterday. "It's great news for the team that has worked so hard on this project."

The project includes a huge glass atrium, accessible to the public, at the heart of the hotel, with a 'skycatcher' -- or oval glass roof -- allowing light to enter the building. The basement will be home to a swimming pool called 'Dubh Linn', with the 'sky bar' at the top of the building providing views across the city. No date has been set for construction to begin.

However, the project has caused outrage among conservationists and the Department of the Environment because it involves the virtual destruction of the Clarence Hotel, an art deco building dating from 1937; four Georgian buildings from the early 19th century; and Dollard House, which was built in 1886.

All are listed buildings, and only the facades along Wellington Quay will be preserved.

There were seven objectors, and legal action aimed at overturning the permission is likely.

Yesterday, An Taisce said the board had set a precedent which could see other listed buildings demolished to make way for new developments. This is only supposed to happen in 'exceptional circumstances' -- where a building was dangerous, for example -- and none had been demonstrated, it said.

"The proposal does open up a precedent on the quays," An Taisce heritage officer Ian Lumley said. "This undermines the architectural conservation area, and it could be the subject of legal proceedings. The board are venturing into very dangerous territory."

In overturning its inspector's recommendation to refuse permission, the board said the high quality of the revamped hotel and benefits to the area meant the project would be in accordance with proper planning and granted permission subject to 19 conditions.