No one, not even the Buildings Department, is certain how many illegal additions or alterations have been made to buildings in Hong Kong. Some estimates put the figure at 800,000, others considerably more. Whatever the number, the government is struggling to carry out inspections and enforce guidelines and rules, as a recent Audit Commission report made clear. At the least, a review of the system is necessary to ensure that our city is a safe place in which to live and work.

The auditors found the department had fallen far behind in issuing removal orders and ensuring that the clearances were promptly carried out. As of last October, there were 68,134 outstanding orders, 21 per cent of which had not been acted on for between six and 10 years and 1 per cent for up to 30 years. Large-scale inspections were also found to be far behind schedule. These are worrying revelations for a city so densely packed, where high-rise living and the threat of severe tropical storms require that the highest safety standards be maintained.

We have found the consequences of letting standards decline to our detriment on too many occasions. Fatal fires have been traced to illegal structures and blocked emergency exits, while a city-wide inspection of buildings 50 years and older was ordered in 2010 after a five-storey tenement in To Kwa Wan collapsed, killing four people. But the problem cannot easily be resolved. Given the circumstances, strict enforcement may not be practical or even possible. Regular changes to building safety laws that are more than half a century old have made determining what is and is not legal a complicated matter - sometimes, even professionals are not sure. The demand for low-cost housing and budget tourist accommodation has created further challenges through the profusion of subdivided flats. Enforced removal could be costly and disruptive.