Tall buildings are getting greener

Urban density is a pressing, global issue, and cities around the world are striving to keep their areas green, sustainable and liveable to cater for their increasing populations. Done right – and smartly – high-rises can be a solution to the challenges, according to experts.

Deo Prasad, Director of the Centre for Sustainable Built Environments at the University of New South Wales in Australia, notes that urban sprawl is “a far worse option than high-rises”, because a lot of transport problems and their associated health and economic impacts can be avoided.

This is especially true when building considerations extend beyond buildings as standalone elements to encompass additional factors such as roads and other infrastructure requirements as well as the energy impact of transport.

However, high-rises as standalone buildings can also be made more sustainable and become part of the solution to the resource and climate crises. One way to achieve this is to use prefabricated components manufactured in a controlled, offsite environment – which not only cuts costs and improves health and safety for workers but also reduces noise and minimises the impact of construction on the local area by, e.g., lowering air pollution and CO2 emissions.

The advantages of prefabrication become even more apparent with high-rises, as the labour and transport reductions realised are even larger than with low-rises. Another way is to minimise energy demand by using smart solutions like double skin facades, which improve insulation and minimise solar gain while still maximising natural light – or by incorporating onsite energy generation into the building design, as Ramboll has done with wind turbines on one of the Middle East’s most iconic towers, the Bahrain World Trade Centre.

It is also possible to build a literally green high-rise – whose greenery benefits both environmental sustainability and human liveability. To cater for Singapore’s ageing population, Ramboll’s landscape architects partnered with WOHA Architects to design and build Kampung Admiralty (pictured), Singapore’s flagship ”vertical village” – the first public development that integrates housing with public facilities for both young and old on a compact 2.2-acre site.

As several scientific studies have shown, having green areas close to home – or even just looking at plants – can offer psychological benefits, reduce stress and improve concentration.

"We developed a diverse and dynamic planting palette to serve as an inviting public environment for active living, including community gardens that exhibit local fruit tree species once in abundance at kampungs, or villages, giving the old familiar memories from their past and reminding the young of their history", explains Tobias Baur, Project Director of Kampung Admirality and Director at Ramboll Singapore.

The lush greenery forms a contiguous horizontal canopy, capable of lowering surface and air temperatures by providing shade and dissipating urban heat island effects, which in turn saves the energy used on air-conditioning, among other things, keeping the building and its users naturally cool.

Water is also an aesthetic, therapeutic and sustainable element at Kampung Admiralty. Much of the rainfall runoff from the upper stratum and the two tower roofs is collected, filtered and recycled. A lot of the runoff ends up in an ecopond on level one, where a cleansing biotope recirculates and cleanses the eco-pond water.

This also helps to promote biodiversity and natural cooling effects – and as gravity helps the water to flow, the reduced need for pumping systems lowers energy consumption.

"The average annual rainfall in Singapore is 92 inches (2340mm). This means that over a million gallons of tap water can be conserved each year if the stormwater runoff is stored in the rainwater harvesting tank and reused for irrigation – approximately the average water consumption of 200 public housing, five-room flats in one month," stresses Tobias Baur.

Written by Michael Rothenborg