B+B Construction faces a bill estimated at $500 million to secure piling work at the International Finance Centre (IFC) being built as part of the Hong Kong Central station property development. The 38-storey IFC is being built by the Central Waterfront consortium, a joint venture between Sun Hung Kai Properties and Henderson Land Development, which won the development rights from the Mass Transit Railway Corp. Lead tenant in the development is ING Barings which is leasing up to eight floors, or 142,000 square feet. About 35 per cent of the 784,000-sq ft building has been leased so far. The problems arose after tests revealed the piles either did not reach rock level or had not been drilled into the rock. The Buildings Department also refused to approve the piling, insisting remedial work be carried out. This involved pumping hundreds of tonnes of concrete below ground to secure the piles to the rock. One structural engineer said: 'It is a tactical decision where to put the piling. B+B Contractors appears to have taken a decision based on an engineering judgment, but the Buildings Department will not accept it. They wanted the piling down to full blown rock. 'Consequently, the Buildings Department either required repair work to be carried out or tests by the contractor to ensure the piles were able to take the full load of the IFC on top. 'But to carry out suitable tests would have required putting a 2,200-tonne weight on each pile. There is no way you could test the piles as they were.' He said remedial work would cost 'several hundred million dollars', although another specialist estimated repairs at $500 million. The prominent companies involved in the project stone-walled questions when approached by Sunday Money. B+B managing director Alex Au said: 'I can't make any comment.' Aoki Corp, the Japanese contractor building the main superstructure, referred all calls to the Central Waterfront consortium. Alan Cheung, Central Waterfront consortium project manager, said the remedial works had been carried out 'to the satisfaction of all relevant Government departments'. He refused to answer further questions, but believed similar difficulties had occurred at property developments at Kowloon and Olympic stations. Thomas Ho, the MTRC's property manager, also avoided answering direct questions about the piling difficulties. The Buildings Department confirmed an investigation by its development and legal and management divisions was under way. But a spokesman said it was unable to provide any further details while construction was proceeding.