Technology bears fruit, mostly
February 2017

Much has already been written about the rise in high-rise, by which I mean our apparently insatiable desire not only for more towers but for taller towers as well. But the numbers never cease to amaze me. In 2000, there were 215 office towers worldwide above 200 m high, but only three residential towers were as high. Today, just 17 years later, there are 255 residential towers above that height across our planet with, according to a recent article in the Guardian Weekend magazine, a further 184 under construction. The article goes on: “The Jeddah Tower in Saudi Arabia, due to be completed in 2020, will be the first to break 1,000 m. Its highest apartments will be on the 156th floor”. Let’s hope the lifts are reliable, as that is one walk you don’t want to take with your weekly shop.

Having said that, it is advances in lift technology that go some way to explaining the trend for taller towers, as they help to make high-rise living and working practicable. By using high strength to weight ratio carbon fibre ropes in place of steel ropes, lift shafts of several hundred meters are now possible. Advances in motor and control technology mean that travelling at more than 20 mph in a lift is not unusual these days, and zipping up and down at more than 40 mph is possible. To control movement at the top of a tower, sophisticated dampening systems are deployed, limiting any swaying motion in the breeze (if you were not already feeling queasy after the lift ride anyway) and potentially preventing the tower from falling over in a storm.

Of course, advances in facade technology are also important enablers for such super-skyscrapers. For example, while unitised facades have been around for more than 50 years, their modern incarnation is transforming installation and operational costs. Pre-assembled units are now delivered to site and installed to the principles of Just-in-Time, minimising any wastage of time and resources. Where necessary, the units can be stored inside the building and then transported to the installation site via a fixed track and assembled by highly qualified teams. It is also increasingly important to ensure that ease of maintenance of the facade is built in as standard, for obvious reasons. We are seeing greater use of double-skin facades, with ventilated cavities and integrated motorised shading systems. Such interactive facades can react automatically to external conditions and occupant comfort requirements, maximising daylighting and views while reducing the risk of overheating in summer and increasing solar gains in winter, as well as providing fresh air and cooling through natural ventilation. Critical to the continued success of such increasingly complex facade systems that optimise function and efficiency is to ensure that they are also easily managed by end-users.

The Guardian article mentioned above carried interviews with a selection of people living in high rises. The amazing views and natural light shows feature prominently, as one might expect. For one family, living on floor 74 means that they have no need for broadcast traffic reports when setting out on the school run. Just a glance out of the window is all they need to work out the best route to school. I couldn’t help finding it somehow rather poignant though that, for one resident living in a penthouse suite boasting an olive grove of 30 healthy trees, as bees don’t fly that high there is no pollination, so there are never any olives.