Say you wanted to sell your flat. You'd want to consider how the broader market was moving, what neighbouring flats had fetched recently, who the likely buyers might be - oh, and how big your own place was. That seems pretty basic. And given how central a place real estate occupies in the minds of many Hong Kong residents, you'd think it would be for the government as well. Alas, no. When it decided to put the former marine police headquarters in Tsim Sha Tsui out to tender - a historically important building on prime land in one of the most expensive parts of Hong Kong - it failed to survey it accurately. And so a building that was estimated to have 4,300 square metres of floor space turned out, after a proper assessment, to have almost a third more space. Cheung Kong (Holdings) subsidiary Flying Snow won the tender with a HK$352.8 million bid. With so much funding at stake, it surely made its own estimate of the area involved. But it isn't a bidder's job to inform the government of inaccuracies, and after it won the tender and took over the site, it made the government aware of the mistake. Cheung Kong doesn't need to answer for this error; the government does. It's now academic whether the site would have fetched more if the actual area of 5,610 square metres was in the tender document; it certainly would have allowed the public - and stock analysts - to better compare the deal to other prices in the vicinity. And while we can't roll back the clock, we can certainly put in a full effort to find out how this happened so that a repeat can be prevented. The Audit Commission has opened a file on the error and has contacted the Lands Department for information. That's a start, but the public deserves a full study and report on the transaction. Land is the government's biggest revenue earner - we need to make sure we have the mechanisms in place to get the best deal possible every time we do a deal. And that doesn't simply mean the highest price. As the community has clearly signalled, we're increasingly concerned about the quality of our environment and the preservation of our heritage. Indeed, the ultimate redevelopment of the site - now called 1881 Heritage - has drawn much criticism for the creation of another glitzy shopping mall selling high-priced goods, with much less evidence of heritage preservation, conservation and open access. Historically, the 129-year-old buildings were significant to Hong Kong's evolution as a trade centre, having at one time been a signalling post, battery and a place for mariners to stay. Before redevelopment, the tree-studded hill on which they were built was an oasis in the heart of one of our busiest tourist and shopping districts. What was created should have been mindful of these elements and ensured they were preserved for the enjoyment of all. Instead, most of the 193 trees were cut down or moved. The main building and a stable were converted into an exclusive hotel and bars and restaurants, restricting their access to visitors. A new structure built to appear as if it was part of the original complex was put up to house a row of shops. Fountains were built and marble flooring laid. Only the observation tower was retained for all-comers to look over. So price isn't everything. But whatever it is we as a community want from any land sale, we need to be sure that we've done all our due diligence so we know exactly what we're asking for - and what we're selling.