The National Development and Reform Commission has recently issued a circular saying no building higher than 500 meters will be given clearance. There are very few such tall buildings in the world, and a majority of them are in China.

There are many reasons why China has so many super-tall building－surmounting technological challenges being one of them. China's booming economic development may have facilitated the construction of such buildings, but they do help attract heavy investment. For example, super-tall buildings become landmarks of a city, prompting many decision-makers to allow their construction.

Also, the construction of such super-tall buildings boosts the development of the construction industry, while giving enterprises an opportunity to derive economic benefits. However, super-tall buildings also face numerous design and technological challenges. First, the space is not always used efficiently, while their operation and maintenance costs keep mounting. After all, super-tall buildings require various higher-standard auxiliary systems, such as elevators, escalators and air conditioning.

There is also the need for a special floor where people can seek refuge during emergencies such as a fire, which is a huge drain on resources. Also, the daily energy and resource requirements of super-tall buildings are far higher than for ordinary buildings, running counter to the current concept of energy and resource conservation.

The construction of super-tall buildings also poses other challenges. Once a super-tall building goes up in an area, it puts increasing pressure on the traffic, facilities and services around them, not to mention firefighting, evacuation and rescue plans.

In many cases, super-tall buildings have to rely on internal automatic firefighting facilities to extinguish fires, otherwise everyone has to move to the refuge floor and wait till help arrives from outside. The construction of such super-tall buildings is often a long drawn-out process and can encounter economic challenges and uncertainties.

In a nutshell, a lot of scientific and prudent decision-making must precede the construction of a super-tall building, as a host of economic, technological, safety and other factors have to be taken into consideration.