Santamouris heat stress extreme heat events
Cityscape illustration by Dante Terzigni

As extreme heat comes our way and threatens to impact on our buildings, it’s time to acknowledge that the quality Australia’s urban fabric is not on a par with other parts of the world.

“The cost of buildings is very high in Australia, so there is enormous opportunity to increase quality without increasing cost,” Professor Santamouris says.

But it still needs an “active state” to drive better regulations.

He says it is very important we borrow from the international experience and translate it into our policies.

Developers and builders should take action now to ensure properties are safe during extreme heat events, according to urban heat expert Mat Santamouris.

As professor of high performance architecture at UNSW he says the role of developers in addressing the growing impact of extreme heat in areas such as Western Sydney is a “key question”.

Two things that can be done

There are two ways the property sector can respond to the quality of buildings in terms of responding to climate change and urban heat.

The first is to leave it to the market in the hope it will self-regulate.

The second is for states to impose stricter conditions on builders regarding thermal performance.

Professor Santamouris says this approach has worked for Europe, China, Japan and Singapore.

Almost six years ago the EU instituted a policy that all buildings be close to net zero by 2019 or 2020.

Mat Santamouris, UNSW

“Industry said it would increase the cost of building, but because of the strict requirements, immediately the market responded.”

The result, according to Professor Santamouris, was the delivery of buildings that provide a better quality environment and have improved microclimates.

The measure also addressed the issue of growing energy consumption. Since standards were raised, the rate of consumption growth has taken a downwards trajectory.

“The new energy consumption measures worked very well.”

This is a lesson Australia should heed.

Australia needs to raise standards

“Standards have to be more strict,” Professor Santamouris says.

The quality of buildings in Australia “does not correspond” with the standards achieved elsewhere in the world, which means there is “a tremendous opportunity for improvement”.

“The cost of buildings is very high in Australia, so there is enormous opportunity to increase quality without increasing cost,” Professor Santamouris says.

But it still needs an “active state” to drive better regulations.

He says it is very important we borrow from the international experience and translate it into our policies.

Western Sydney on the front foot

Western Sydney councils are already engaging with the challenge.

Research led by Professor Santamouris in conjunction with the CRC for Low Carbon Living for Sydney Water in 2017, the Cooling Western Sydney study, looked at eight sites across the west, including Penrith, Canterbury, Liverpool, Bankstown, Fairfield, Campbelltown, Hawkesbury and Parramatta.

It examined temperatures and corresponding mortality and morbidity data between 2014 and 2017, and examined a range of interventions to reduce urban heat and its impacts on people in the area.

Planting trees was not the only measure proposed. Others included the use of water technology such as water curtains, pools, evaporative wind towers and fountains, along with increasing the solar reflectance of roofs, building facades and pavements.

The study showed that implementing the suite of measures could reduce the peak ambient temperature in the region by 2.5°C and reduce peak energy demand by almost five per cent.

Heat-related deaths could also be almost halved from a cumulative rate of 14 people per 100,000 people to 7.5 per 100,000.

He says there has been great interest in his findings, and that the Greater Sydney Commission and City of Parramatta have asked him to continue the research.

The ongoing study is also being carried out with Infrastructure NSW.

Progress elsewhere is slow

Wider change is not happening at such a rapid pace.

“To change something takes time,” Professor Santamouris says.

There have been some gains, such as new policies around Western Sydney parkland, and an attempt to influence the design of the new Western Sydney Airport to increase climate change adaptation and ensure more liveable conditions in the area.

But the need for policymakers to take up the mitigation and adaptation challenge is only going to increase.

“By 2050 we may have a serious problem,” Professor Santamouris says.

Currently temperatures of between 45°C and 48°C have been recorded in the west during peak heat events – temperatures could “easily exceed” 50°C.

“There is an urgency,” he says.

Increased energy consumption driven by demand for cooling also means there will be a need to adapt the power system.

Under current policy and market settings, new power stations could be built that are only switched on a few times a year to meet extreme heat peak demand.

“There would be a tremendous impact on the economy,” Professor Santamouris says.

“The administration has to understand the problem and its real dimensions.”

Currently we have authorities who are “always surprised” when extreme heat events occur.

“Once [state and local governments] understand, then they can make proper design policies.”

What we do know is the “whole system” will be affected by heat events – the energy system, the economic system and the health system.

Professor Santamouris points out that studies have shown that where there is investment in the types of microclimate interventions that reduce heat impacts, 35 per cent of the profits return to the health system.

It is necessary for everyone to “be proactive”.

  • “We know the problem. We can expect the problem. Now we need much better policy.”

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  1. We are talking the same language, so how do we make it happen. We need to tell a better story.
    The Australian Institue of Refrigeration Air Conditioning and Heating advocates for low-emission HVAC systems, which means:
    • The envelope of the building or container, its thermal performance and the air-sealing characteristics must all be optimised to ensure that the minimum amount of climate control energy is required.
    • Systems are accurately sized to meet documented realistic operating requirements, and are installed, controlled, commissioned, monitored, operated and fine-tuned to ensure optimised energy and water consumption rates.
    • Systems are designed to have a reduced environmental impact, measured over the entire life-cycle of the system.
    • Low-energy high-productivity systems that utilise energy recovery where practical, either within the system or within the building or facility.
    • Low-GWP working fluids and tight system construction standards, minimising leaks and maintaining an optimum refrigerant charge.
    • Real-time monitoring of electrical, water and refrigerant inputs and outputs, system self-diagnostics and alarms, free-running systems and free-running buildings or processes when outdoor conditions allow.
    • Optimising ventilation, thermal comfort and indoor environment quality outcomes in buildings, with controls that are adaptive to external climate conditions and internal occupant needs.
    Low-emission HVAC costs more to procure than the industry standard, but costs much less to operate and generates better long-term outcomes for businesses, owners, and environment.

  2. In a climate that is drying and has a shortage of water, surely it is foolish to consider using pools and water walls as cooling options when other non energy consumptive options are available