While the processing and analysis methods seem more efficient nowadays, this hasn’t always been the case in recent years, as the specialist confirms: “There have been location errors in the past, for instance, residential towers built in the middle of a motorway intersection... Or towers where the design didn’t let enough natural light in. In this case, the best thing to do is to renovate them or demolish them. For instance, the old AXA tower in La Défense (Paris) had these disadvantages and major renovation works were carried out to create bigger openings to let more natural light in.  The floors were also widened and the facades completely changed. The entirely renovated tower is now more functional and comfortable”.

Residential towers have to respect additional standards. Their height limit depends on the regulations of the town concerned. “Some towns have height ceilings included in their local planning regulations, like in Paris. Other towns don’t have height limits but there is a relatively controlled negotiation with the authorities”, the French researcher points out. The height will also have an impact on the rental price. “The higher up the apartment, the higher the price (because of the better light and view). But the town, neighbourhood and environment of the tower have a strong influence on this.  In a tower without a view, there will be less difference between the apartments on the upper and lower floors”.

The green tower syndrome

The idea of the sustainable city appears increasingly at the heart of many reflections and numerous avant-garde and futuristic projects. “And so much the better!”, Claire Saint-Pierre confirms. “It’s often these projects that help things progress the most. Today, some so-called ‘ecological towers’ are being built, such as the Shanghai tower.  The Bahrain World Trade Center Manama has already been built and can be considered an ecological tower. These buildings contain many elements of sustainable architecture: geothermal energy, architectural design to reduce the effects of the wind, the use of double-skin facades to regulate air flows, the use of vegetation on the floors, etc. As for vertical farms, they are still in the project stage and are related to the stakes of urban agriculture”. The idea of vertical farms came about in 1999, conceived by Dickson Despommiers, a professor in environmental science and microbiology. Convinced that they can solve food shortage problems, the researcher is their tireless defender. In his opinion, “by the year 2050, nearly 80 % of the earth’s population will reside in urban centers. About 20 % more land than is represented by the country of Brazil will be needed to grow enough food to feed them.”  

Size matters

There have been major advances in techniques and technologies in terms of tower construction. In engineering, thanks to the development of calculation and simulation tools, it is possible to build huge projects (towers, bridges, stadiums, etc.) and the risks of collapse are usually taken into account by the engineers, especially in seismic areas. “The quality and the precision in the calculations and construction are very important. If all the precautions are taken by the engineers, there aren’t many risks. The reason buildings usually collapse is because their structure is damaged, after a fire for instance. The problem of great height is, above all, the damage a collapse could cause to the surrounding area”.

Space saving isn’t necessarily the ultimate goal, even if it is often used as an argument for high-rise building projects. By nature, humans seek to go ever higher. The current record is held by Burj Khalifa: an outrageous 828 metres stretch skywards, above the city of Dubai in the United Arab Emirates. But humanity has no intention of stopping there... currently under construction is the Kingdom Tower in Jeddah (Saudi Arabia) which should be finished in 2018 and reach a height of 1001 metres!  “The very symbolic bar of one kilometre will undoubtedly be reached! Personally, I think these projects are completely insane and I prefer a walk in the mountains to reach such heights”, the young researcher concludes.