We tend to think of buildings as permanent. There is even an English phrase, “As safe as houses,” which is presupposed on their ability to withstand damage and protect their contents. But is this justified? The building next to the one I’m sitting in has just been demolished, and across the road there is a new office building which opened this year next to another demolition site. Within the block there are another three buildings that were completed within the last 5 years, all on the sites of large buildings built in the last 50 years. There is a reason why there is so much redevelopment here. A new MTR station will open later this year and the area is changing from light industrial to commercial. Similar changes are taking place in many areas across Hong Kong.
Elsewhere in the world, we can see structures that were built much earlier. In England, the Tower of London and Lincoln Cathedral have stood for over 900 years. The Great Wall of China started construction about 2,200 years ago, although much of the wall that stands today dates from the Ming era, 6 centuries ago. The Great Pyramid of Giza is about 4,560 years old and was the tallest structure for over 3,800 years, until Lincoln Cathedral surpassed it. The Pyramid of Djoser is 4,650 years old and also was the world’s tallest structure when it was built. The oldest three stones at Avebury in Britain were erected about 5,000 years ago and the other stone circles there were erected in the following 6 centuries.
The first impression is that ancient peoples built things to last, while modern buildings are ephemeral. This is misleading. The tomb of the minor king Mausolus was considered as one of the Seven Wonders of the (Western) World, but today it only exists as the origin of our word for a large tomb: mausoleum. In fact, of the Seven, the only Wonder that still stands is the Great Pyramid of Giza. Even that has suffered damage; the fine, smooth outer covering of white limestone has disappeared over the centuries, and was probably used to build Cairo. Stonehenge and Avebury have also been used as unofficial quarries. Ordinary structures like homes, workshops, and livestock shelters seldom survive at all. Most were built of materials that decay: wood, thatch, or bamboo. Archaeologists go to extraordinary lengths to piece together how our ancestors lived and worked from the buried fragments that remain.
It is distressing to search the Internet for “building collapse” because it reveals many modern instances of building disasters. In 1995 the Sampoong Department Store, Korea collapsed, killing 502 people. The account of the disaster reveals how that, during construction, the owner tried to increase profitability and fired construction companies that warned the changes were dangerous. Negligent construction has also been blamed for the collapse of a block of flats in Tainan, Taiwan during an earthquake in February 2016 that left 115 people dead. Do these incidents show that modern construction is inferior to ancient methods? At least three of the Seven Wonders were destroyed by earthquakes, and innumerable ordinary structures have fallen to earthquakes, fires and floods. Nowadays, modern engineering knowledge makes it possible to build safe, lasting buildings, and building codes impose standards that should keep us safe. The failures are few compared to the numbers of buildings, but we need our building inspectors to stay vigilant.
So will today’s most impressive structures, such as the Abraj Al-Bait Towers, the kilometer-high Kingdom Tower, both in Saudi Arabia, or the Burj Khalifa in the United Arab Emirates last as long as the pyramids? It seems doubtful that these exquisitely engineered pinnacles could have the staying power of the massive pile of rock that is a pyramid, but there may be hope. The Tower of London and Lincoln Cathedral are both in very good condition, despite being 900 years old and this is because they have been continuously in use, and therefore continuously maintained and modified over that long period. If these modern skyscrapers remain useful and relevant to our descendants, then they will be maintained.
What of the construction in my neighborhood? One of the old factory buildings has been refurbished into a “work-life balance themed complex with 18 floors of offices and 4 floors of retail shops.” It has survived, at least a little longer, by becoming something else.
However, the modern structures that I guess will survive the longest were designed to be used once and then abandoned. The Apollo Lunar Lander Descent Stages have the advantage of resting on the airless moon, where there is little tectonic activity. They will not suffer corrosion or erosion and, barring an unlucky meteorite strike, they will be there for a very long time.