It is not often that public opinion has a decisive impact on development in this city. But that is the case in revised plans for a HK$2.4 billion extension of the University of Hong Kong campus. After a public outcry, a historic waterworks on the development site that was marked for demolition is now to be preserved. As we report today on Page 4, it took a lot of engineering design and creative thinking. By going the extra yard, university chiefs have shown that they were actually listening to what people had to say. That sets a positive example for which we can be grateful. After all, if heritage and history are not valued in a seat of learning, where can we expect them to be respected? That is not an idle question. As we also report today, nearly 10 per cent of 607 historic buildings listed by the Antiquities Advisory Board since it was set up in 1980 have been knocked down. Unlike declared monuments, nearly 500 listed historic buildings remain unprotected from demolition. That is not to say that they are all worth preserving without regard for a sensible balance between development and preservation. But as things stand, public opinion may be all that stands between them and the wrecker's hammer. The list helps by identifying the buildings, which means that public pressure can be applied if it becomes known that one of them is in jeopardy. But otherwise there is little point in having a list if they face demolition anyway. The controversial demolition of the Star Ferry pier and the fight to save Queen's Pier highlighted the need for an effective system for protecting heritage. The newly formed Development Bureau has been given responsibility for formulating a new policy. A senior government source says it understands the need for tools to enforce it. This would probably mean having to give a body like the Antiquities and Monuments Office more teeth. Difficult issues arise when heritage properties are in private hands, not least the rights of the owners and the cost of buying them out. Now that heritage preservation has touched a sensitive public nerve, they should not be left unaddressed much longer.