Sustainable buildings “could become mainstream”. This was a comment made by Pritzker Architecture Prize Laureate Sir Norman Foster at the opening keynote of the Forum of Mayors on Oct 6, organised by the United Nations Economic Commission for Europe.
“We now have scientific evidence to prove that green buildings with natural ventilation are not only good for your health, but they enable you to perform better,” said Sir Norman.
While these are currently the exception, he predicts they will soon become the norm — and it is therefore important that the building industry gets on board with this.
One organisation that does a significant amount of research in sustainable buildings is the National University of Singapore’s School of Design and Environment (NUS SDE). In addition to studying solutions that make them environmentally friendly, the School has recently added a new focus: pandemic protection, in response to Covid-19.
Collectively, NUS SDE now has a comprehensive toolkit the building industry can employ to improve the standard of living of people — including their health and well-being — who occupy these buildings.
These include hybrid ventilation systems, sensor technology and passive design strategies that can be integrated into office towers, retail malls, residential blocks, hotels and civic buildings, just to name a few.
A new way of thinking
Before the toolkit gets updated though, a more fundamental rethink of building design is necessary. It involves a transformation — in and among all the stakeholders in the architecture, engineering and construction industry, including the end-user, to acknowledge the importance of and need for sustainable buildings, and embrace them.
Compared with other fields, the uptake of technologies to design, construct and operate buildings has been laggardly slow despite the continual advances across a broad spectrum in science and technology, says Dr Tham Kwok Wai, an associate professor in the Department of Building at the NUS SDE, and an expert in indoor air quality and thermal comfort.
“We sent men to the moon in 1969. Don’t you think that technology 50 years ago has actually improved to the point that we can achieve similar advances for our facilities?”
“There has been insufficient translation and adoption of innovations that would have made buildings safer, more pleasant and responsive to human needs. We must usher in a new set of environmental controls and paradigms that are commensurate with the other realms of life that have already moved so far ahead, such as healthcare and computer science,” he adds.
To this end, he advocates embracing a holistic way of thinking through the repertoire of strategies and technologies that are available, before synthesising and synergising them to achieve an overall better outcome.
“It’s like how a French chef has a wide collection of knives and has to use the right one to cut the different ingredients, at the appropriate time, and then skilfully blending them to bring out the best in the quality of his dishes,” explains Dr Tham.
“The same must be thought about when we rethink how we design buildings, and how we want to operate them.”
Tools for increasing well-being
Already, there are real-life examples that demonstrate the possibilities, such as the groundbreaking NUS SDE4 building.
It is the first certified Zero Energy building by the International Living Future Institute in South-east Asia, meaning 100 per cent of its energy needs on a net annual basis are supplied by on-site renewable energy, with no combustion allowed. It also has a hybrid cooling system that makes optimal use of air-conditioning.
The latter is new and particularly relevant as the planet warms. It maintains a higher internal air temperature of up to 27 deg C (which ensures less energy is spent to cool it) and uses the cooling effect of ceiling fans to achieve thermal comfort. The outdoor air is simply brought in, cooled slightly, and then fully released back outdoors without the conventional practice of recirculation that potentially retains and spreads indoor contaminants and germs.
“When you increase the air temperature, you want to also increase air velocity to maintain the same level of comfort,” says Mr Bertrand Lasternas, an associate director of energy management at NUS SDE.
“It offers 100 per cent fresh air and in constantly flushing the air out, including the pollutants and germs, we are creating a much more high quality indoor environment. The air is also treated with high efficiency filters to remove outdoor pollutants to achieve an indoor air quality commensurate with stringent requirements of the best of building standards such as the WELL Standard and the Singapore Green Mark Platinum scheme.”
Its hybrid nature is imbued by making all of SDE4’s windows and doors openable to maximise the air flow through the building when outdoor conditions are appropriate, thus allowing it to be naturally ventilated.
Another tool to consider when rethinking building design is sensor technology and analytics. While not new, its potential has not been well exploited.
Smart building owners and users are faced with a lot of data but do not know how to extract real value from this information overload.
“Before investing in any sensor technology, it is important that we think about how they can be used to understand, manage, and improve building performance,” says Dr Adrian Chong, who is an assistant professor in the Department of Building at the NUS SDE.
Sensors are synergistic with building design and controls, and buildings should be designed to provide the capability to react to the sensor readings. “Modularising building systems is one way to provide flexibility to adapt to varying conditions and robustness towards future uncertainties.”
For instance, occupancy at the workplace has become sporadic with the Covid-19 pandemic, and modular systems with occupancy sensing bring the added ability of optimising energy efficiency while meeting ventilation requirements.
Passive design strategies are another tool that can be systematically considered and integrated. This involves working with nature as much as possible and then supplementing a building with active energy systems.
Examples of such systems can be found in SDE4, such as a façade that is visually porous to allow light through while enhancing visibility of the outside. It also facilitates wind passing through to keep the internal spaces naturally ventilated and cool, while reasonably keeping the rain out.
While it is easy to get swept along by digital innovations, Dr Tham rightfully points out that technology is just one component of the toolkit. In order to fully rethink building design to make them sustainable, it is important to acknowledge the past.
“In rethinking design to shape a sustainable future, we need to know where we have come from, while recognising and responding to the present,” he explains. “More importantly, the design must embrace the future as a long-term commitment.”
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