Worldwide, there is a growing emphasis on delivering buildings that won’t just survive routine wear and tear but will also be able to handle extremes—heatwaves, power outages, and flash flooding. Jobsite consulted some leading Australian experts to find out what makes for a resilient building and how project teams can add the right elements to deliver them.
Paul Stoller, Co-Chair of the Australian Institute of Refrigeration, Air Conditioning and Heating’s (AIRAH) Special Technical Group on building resilience and Managing Director of Atelier Ten’s Australian studios, tells Jobsite there are both short-term and long-term aspects to resilience.
In the short-term, it is about ensuring a building can offer a safe shelter through events of a short, sharp and extreme nature, such as a power outage, social unrest, severe storm, or flash flooding.
In the longer-term view, it is the ability of a building to adapt to changing circumstances like climate change or shifts in economic and social circumstances.
The most important thing about resilience is that there is more to it than just adding a specific widget or a single design change, Stoller explains.
Push for Safety
Resilience is created through designer, builder and facilities managers sitting down in the early stages and thinking about what could go wrong or change, and how to enable responses through design, construction and operation.
“It is a risk-management process,” says Stoller.
Stoller says thinking about how safe a building will be to maintain, for example, during temperature extremes, is also important. A good builder should be “committed to safe building operations,” he says. That means it needs to be inspectable, serviceable and maintainable safely, even during a crisis.
Builders should “push hard” for safety, he says. “Good builders help everyone lift their game.”
Redundancy is Key
Another key principle of resilience is redundancy—the extra capacity in terms of energy, water or thermal comfort—that can be utilised during a disruption or extreme event.
The key is achieving a “good balance” between appropriate redundancy that will carry the building through multiple failures and the capacity required for normal operation.
An example of a contemporary building that has taken an intentional resilient design approach is the buildings at Barangaroo, Stoller says. Elements of the resiliency include shading on the façades, locating the public plaza above potential flood levels, and the use of “harbour cooling” for the precinct cooling system. The use of water from the harbour for cooling makes it easier to maintain operations on peak heat days, Stoller says.
Looking to Older Buildings
There are also older Sydney buildings that can serve as examples of resilience—the sandstone buildings constructed in the 1800s on Macquarie Street, Kent Street and Castlereagh Street in Sydney.
“They are productive, healthy buildings that are still socially relevant,” Stoller says.
The size of the windows ensures the interiors have sufficient natural light even if the power goes out, and the stone construction means they can to some extent “self-regulate” for temperature.
The high ceilings also allow for multiple uses of the spaces.
“They are big, simple robust buildings and a good fit for almost anything. They were designed for a time before we had the services we now rely on.”
Nicki Parker, Brisbane Sustainability Manager for leading engineering consultancy Norman Disney & Young, tells Jobsite that passive design is “absolutely critical” for resilience.
It needs to be a balanced approach, however. She notes that the current trend for highly glazed façades to bring in natural daylight at the same time provokes excessive heat gain. A more rationalised approach would include appropriately sized windows to reduce that heat gain while still harvesting the daylight.
In the southern states, being able to seal up a building to keep heat out is important, meaning blower door testing can be valuable, Parker says. However, in the tropics, it can be more beneficial to allow air to move between inside and outside.
Builders, therefore, need to “understand the local conditions,” Parker says.
Another consideration is ensuring the plant is installed above any potential flood risk, and taking into account sea level rise. It is also important to consider what is located around the plant.
Green Roof for Cooling
When placed on the rooftop, details like the rooftop’s colour can have an impact on its resilience, she explains. A dark roof absorbs heat—pushing the local temperature up to 60 or 70 degrees—and not all mechanical equipment is designed to function at such extremes.
“You should go for the lightest roof colour you can get,” Parker advises. “Or have equipment surrounded by a green roof, which has a mild cooling effect and absorbs less heat than concrete.”
A green roof has another bonus. I’s cooling effect could also be used to slightly cool air before it is taken into the building ventilation system.
Power supply is also a key consideration. Ideally, all buildings should have a back-up power system. Parker says it is likely battery storage will increasingly play a role in emergency power, as batteries can be easily retrofitted, making them “an easy quick fix.”
Water is another key issue to consider. High-rise buildings often do not have a water supply to all parts of the building if the pumps are driven by mains power that has been disrupted.
Parker says teams need to plan for water, deciding beforehand how clean, safe water can be provided to occupants in event of an emergency.
What a Builder Should Ask
Parker outlines five key things a builder should ask when creating a framework for resilience:
Is the building at risk from climate-based hazards?
What are the expectations of the owner during and after an extreme event?
What are the operational limits of key plant and systems, including energy and water?
How would the building operate with no mains power?
Are power supplies including back-up power exposed to the elements?
The value-add of thinking about resilience is that resilient buildings often perform better than standard buildings during normal operation, Parker says. It also doesn’t need to run up any extra costs if the project team “thinks about it early enough” in the process.