Officials still face hurdles before they can press ahead with the Government Hill redevelopment and release the site on a 50-year lease.
The government's plan will have to be vetted by the Town Planning Board. Major opponents of the scheme are also waiting for a board meeting to discuss their counter-proposal.
The Government Hill Concern Group, an alliance of 21 conservation and green groups, submitted a proposal in February to rezone the hill into a 'heritage precinct', keeping it as a site for 'government, institutions and community uses'.
The board, for unknown reasons, has deferred a meeting on the application. Katty Law Ngar-ning, a spokeswoman for the group, said the board had received 6,000 public submissions supporting her plan. She said she had been told the board would meet this year on the subject.
The group is also appealing to the Antiquities Advisory Board, urging it to consider giving a historic grading to a building on the hill designed in the 1950s and called the West Wing.
'The government-appointed consultant did say the West Wing had heritage value, although of a lower one than the Main Wing and the East Wing,' Law said. 'Officials have ignored this point and the board has every duty to discuss the rating.'
The government will have to submit for the board's approval a master layout plan for the redevelopment, and a landscape proposal on preserving nine listed old and valuable trees around the site.
Despite the revisions, an office tower in the plan remains at 32 storeys, the same as in the original scheme. The underground luxury mall originally proposed is being replaced by facilities - the trading hall of Hong Kong Exchanges and Clearing, for example - non-governmental organisations, and some shops and restaurants.
The reduction of underground space was also agreed to minimise the impact on disused wartime air-raid tunnel networks. It means the gross floor area will be trimmed by 4 per cent, from 42,000 to 40,300 square metres.
The tower foyer will be reduced to enlarge the public open space by 11 per cent, to 6,800 square metres.
The parking space will be reduced to avoid worsening traffic congestion in the central business district.
A public park at the site will be designed by the developer winning the bid and will be handed back to the Leisure and Cultural Services Department to manage. Development minister Carrie Lam Cheng Yuet-ngor said this was done to address concerns that the public space would be privatised.
To improve property management, a 'non-alienation clause' will be added to the land lease, allowing the developer to sell the site only as a whole, not broken into parts for sale to different parties.
Shih Wing-ching, founder of Centaline Holdings, said the non-alienation clause would be acceptable because most high-quality commercial towers in Central were already owned by a single developer.