Hong Kong does have a 'new heritage conservation policy' for private sites that started in 2007.
Intended only as a beginning, the three-tier grading system has brought some success and has enabled officials to hand out HK$16 million to subsidise owners of 19 properties who were willing to repair their graded buildings.
But it's been less useful when owners want to give up their buildings for redevelopment. Officials have to negotiate with these owners case by case and offer economic incentives, given that a historic grading lacks statutory protection.
Unlike monument status, the system is only an administrative mechanism, an indicator of a building's architectural, historic and social merits. Officials treat grade-one sites as potential monuments and will offer a range of incentives, such as a land swap, to secure their preservation.
For grade-two and grade-three buildings, officials can try to work out with the owner a plan to selectively preserve the properties. But if the owner insists on his redevelopment rights and turns down the government's offer, officials are out of options.
The grade-one Ho Tung Gardens has dramatically shown that incentives such as land exchanges will not work if the owner is not interested.
Dr Lee Ho-yin, director of the University of Hong Kong's architectural conservation programme, says that in addition to the grading system, the government could also consider some sort of a tax, such as a small levy on property development or gambling activities.
At present, the Hong Kong Jockey Club is the second-biggest spender on heritage conservation after the government. It sets aside HK$1 billion a year for a range of charitable causes, including arts and heritage. Its biggest commitment is the HK$1.8 billion revitalisation of the Central Police Station.
But the club is controlled by powerful stewards who are known to have complicated interests with businesses and developers. It does not have to consult the public on how it allocates the charity money.
Lee says officials should take over the job from the club and set up an independent trust. It could be financed by a charity tax on betting revenues.
New York City takes another approach with its Landmarks Preservation Commission, set up in 1965 in response to citizens' growing concern that important physical elements of the city's history, most notably the old Pennsylvania Railroad Station, were being lost, even though those buildings could have been reused.
Robert Tierney, the commission's chairman, told an international heritage conference last month: 'I believe we have found the right balance between protecting our historic buildings and places, and the rights of property owners. In so doing, we protect the essence of New York City, but not at the expense of economic activity.'
The commission's 11 members, appointed by the mayor, are charged with designating individual landmarks, historic districts, interior landmarks and scenic landmarks.
Designation does not require owners' consent, but goes through a process that includes a possible public hearing and a vote by the commission members. Owners must get a permit from the commission before performing any work and maintain the building in a state of good repair.
Antiquities Advisory Board chairman Bernard Chan says introducing New York's system would mean a 'very radical' change for Hong Kong.
'The Basic Law protects private property rights. In Hong Kong, the issue is that people always tie in property ownership with redevelopment rights,' Chan says.
Given mixed public responses to a possible billion-dollar bill for Ho Tung Gardens, Chan says, a powerful statutory body such as New York's would be even harder to push forward than the competition or minimum wage laws, both of which met strong resistance from businesses.
'There should be a trust to continue the past few years' work and engage more community participation,' Chan says. 'But how far should it go? The community should start discussion now.'