Supertall Building Construction Moving East and Bringing New Challenges, says Allianz
With the latest generation of high-rise buildings reaching new heights of over 600 meters, the supertall construction boom is bringing new challenges as new projects are built higher, faster and with increasing complexity, says insurance giant Allianz.
As the (re)insurer of a number of the tallest buildings around the world, including the next building to hold the title of “world’s tallest”, the one-kilometer high Kingdom Tower development in Jeddah, engineering insurer Allianz Global Corporate & Specialty (AGCS) analysed the challenges of assessing and managing such exceptional risks in its latest Supertall Buildings Risk Bulletin.
The growth of the world’s tallest buildings continues to accelerate in the 21st century as demonstrated by Dubai’s 828m-high Burj Khalifa, towering more than 300 meters over the previous highest building, Taiwan’s Taipei 101 (509 meters).
As soon as 2019, these will in turn be dwarfed by Kingdom Tower which will be the first one-kilometre tall building, ensuring the size of the tallest building in the world will have doubled in just 10 years.
By 2020, the average total height of the tallest 20 buildings in the world is expected to be close to 600 meters, comparable to almost two Eiffel Towers, made possible by a combination of new technologies, innovative building materials and creative design elements.
Construction shifts east
Alongside the continuous race for record heights, a strong geographical construction shift east is taking place. While throughout the 20th century the US skyscraper dominance was undisputed, the vast majority of construction projects today are in China, South East Asia and the Middle East.
Dubai alone is already home to 20 percent of the world’s tallest 50 buildings, while China boasts 30 of the tallest 100 buildings across 15 cities. Indeed, this month China announced initial plans for its own one-kilometre tall building, the Phoenix Towers.
Ahmet Batmaz, Global Head of Engineering Risk Consulting at AGCS, said: “The eastward trend is set to stay, driven by rapid economic and demographic growth, urbanization, strong investor appetite for flagship real estate assets and lower labour costs than in the traditional Western markets.”
Elevators biggest obstacle to first mile-high building
Concepts for the first mile-high (1.6-kilometre) building already exist. However, they are unlikely to materialise for at least another 20 years– largely due to the fact that elevator technology is lagging behind building technology. Current technology limits elevator travel in today’s supertall and megatall buildings to around 600 meters, mainly due to challenges with braking and cabling, although this is expected to change in future.
Other limiting factors include the availability of building materials to potentially replace steel and concrete, but also safety measures for occupants and surrounding areas, damping systems to reduce the negative impact from wind or seismic activity, as well as financing such mega projects.
“The foundations of a supertall or megatall building need to be strong enough to even withstand an earthquake or other natural catastrophe activity,” said Clive Trencher, Senior Risk Consultant at AGCS.
“In the initial building phase particularly, consideration also has to be given to potential exposures such as flash flooding, as there will be large excavations that could get filled with water.
“Significant technical issues to overcome include pumping and placing concrete at extreme heights, maintaining verticality as the building height increases, fire risk and even water and sewage disposal.”
Insuring billion-dollar buildings
Ground-breaking projects bring uniquely challenging risks for insurers, as well as for architects and contractors, which is why AGCS engineering risk experts underline that no two tall building projects are alike. These constructions are inherently highly-complex, as they can involve up to 10,000 workers and over 100 subcontractors each. Data availability and accuracy can be an additional challenge, principally in newly-developed economies.
All project phases – whether building construction or civil engineering – can be insured. Due to the extraordinary size and value of today’s largest buildings easily exceeding the US$1 billion mark, insurance for the complete project is generally granted by a consortium of (re-) insurers. In the case of the Kingdom Tower, AGCS is the leading reinsurer of this building which has an insured value of US$1.5 billion.
But beyond all risk building and construction protection, insurers such as AGCS also provide after construction coverage, known as Inherent Defects Insurance (IDI), to protect policyholders against damages arising from defects in design, materials or workmanship.
“Insurance plays a vital role in evaluating and managing the complex risks of these extraordinary projects. Claims and risk consulting services are particularly important on a construction site with close evaluation of past claims often essential in preventing future claims,” said Ahmet Batmaz, Global Head of Engineering Risk Consultants at AGCS.
Research reveals 164% rise in searches for loft conversions
Market research conducted by building supply specialist Insulation4Less has revealed that searches for ‘Loft Conversions’ rose by a staggering 164% between May and June of this year, while searches for ‘Loft Conversion Ideas’ jumped by 186% as people spend more time on home renovations this summer.
The company also found that the most popular use for a loft conversion is for an additional bedroom, while an extra bathroom was the second-highest search term. Walk-in wardrobes came in third, beating out a home office in fourth while converting a loft into a home cinema round off the top five.
According to a recent study, a loft conversion can add roughly 20% to the value of a property. With the average UK house price standing at £267,000 in January 2021, this represents an average increase in value of more than £53,400.
Johnpaul Manning, Managing Director of Insulation4Less, said: “If the last year has taught us anything, it's that having space is essential to our mental health and wellbeing, so it's no surprise that people are taking the time to focus on home improvements to help them make the most of their home.
As one of the most under-utilised areas in any property, loft conversions represent a great opportunity to maximise the use of space that not only improves quality of life but also has the capacity to add value to the home”, he said.
Manning added that it's important to remember that a loft conversion isn't just your average DIY project, and should never be done on the spur of the moment. “A significant amount of planning needs to happen to make it a reality, and an understanding that life can be disrupted while the build is taking place.
“While it's definitely a worthwhile project, I'd recommend that anyone considering a loft conversion should do some in-depth research to really understand what's needed to make it a reality”, Manning said.
Is Your Loft Suitable For a Conversion?
While loft conversions do look amazing and add an extra element to a property, not all homes may be suitable. Insulation4Less says that this is due to a variety of factors.
“It's important to make sure that your roof is structurally sound enough to handle a conversion”, the company said. Although there are different types of roof structures, they mostly fall into two distinct categories: a traditional roof, and a trussed roof.
A traditional roof: was typically found in pre-1960s houses. Rafters on traditional roofs run along its edges, leaving a good amount of free space. However, they might still need new or extra support. Trussed roofs, on the other hand, have ‘W’ shaped rafters that support the roof and the floor structure. Even though truss roofs may appear to be harder to convert, it’s not impossible; the ‘W’ shaped rafters can be replaced with an ‘A’ shape structure which creates a hollow space. While this can add additional costs, it could be a worthy investment, so take this into consideration during your planning process.
“Another thing to consider is the roof's height and pitch, and how that will impact the amount of space you’ll have. You’ll need a minimum height of 2.2m to ensure proper clearance. While you might be happy to settle for something a little shorter on paper, make sure your happy with the height you have and the effect it could have on the enjoyment of the space”, Insulation4Less advises.
The company recommends doing research before going to an architect or contractor. “Ultimately, look for other conversions on your street or in similar properties, and if you feel comfortable, ask if you can have a look and discuss how their project came together - you’ll find a wealth of information that could really help your own project in the future”.
Information credit: Insulation4Less.