Vertical living is touted as the way of the future for older urban Australians – but there’s a danger apartments could turn into solar ovens during heatwaves. The Fifth Estate spoke to some experts to find out what needs to be done to ensure high-riseapartments are not a hazard, and how leaders in design and development are managing the risks.
With the trend for high-density retirement living gathering momentum, a University of Sydney researcher has sounded the alarm that apartments could be putting the lives of older people at risk during heatwave events.
Dr Leigh Wilson investigated whether Australian retirement living buildings have back-up power to keep the cooling and lifts going if the power goes out during a heatwave.
Her findings were that only five per cent of aged care facilities have back-up power, and that the majority of apartment buildings where older people reside either do not have backup power or are not sure if they do.
“People assume electricity will continue, that there will be access to airconditioning or a fan, and people haven’t thought about how to get out if the power goes down and lifts aren’t working,” she says.
“It highlights that people living in high-rise buildings don’t know they are at risk.”
Heatwaves are a killer
Severe heat events have been proven to increase mortality for people over 65, through worsening the impact of existing health
conditions such as cardiovascular problems in addition to the risk of death from heat stroke or dehydration.
During the 2003 heatwave in Europe, about 14,000 people were killed, and the majority were older people.
There is every reason to believe it could happen here in Australia, she says, particularly given the likelihood of increased frequency, intensity and duration of severe heat events due to climate change.
“This is real, so we need to build adaptation strategies into the way we lead our daily lives,” Wilson says.
“We need to look at construction policies, consider the provision of backup power generation, and ensure there are contingency plans for heatwaves and other extremes weather events such as fires.”
Wilson presented a paper on the topic, Heatwaves, high-rise and the ageing population: are we prepared?,at the Climate Adaptation 2018 conference held in Melbourne in May this year.
Speaking with The Fifth Estate after the conference, Wilson says she identified a gap in research on the impact of climate change on older people in terms of risks posed by their dwellings. Her PhD focused on the impact of climate change on older people.
In the case of the mass deaths in France, the mortality rate was exacerbated by the dense urban environment. People in high rises had dwellings with fixed windows that could not be opened sufficiently for natural airflow, with double-glazing holding in internal heat and those over 65 with mobility problems or disabilities unable to get out of the buildings when the lifts did not operate.
Older people in high-rise apartments rely on airconditioning and fans to keep cool, Wilson says. That means there needs to be back-up power in place to ensure they can stay on if the grid goes down during a heatwave, as has been seen to happen recently in Sydney, Melbourne and Adelaide.
The urban heat island effect also adds to the risks. Wilson says the combination of concrete and glass in the city means buildings radiate heat at night. The ambient temperature in the city at night can be up to five degrees warmer than the ambient temperature in a leafy, low-density area, she says.
“One of the biggest risk factors for heatwave illness is having a small difference between day and nighttime temperatures because the body doesn’t have a chance to cool down properly.”
When this happens for three or four days in a row, there is a spike in cardio and respiratory disease events, and more people become dehydrated.
Glazing trend increases risks
As well as asking about backup power provision, as part of Wilson’s research she asked about the types of apartments people were living in, and whether they got hot.
The trend for extensive glazing meant many apartments got hotter and relied more on mechanical cooling.
The next stage of her work on the issue will involve looking for developers and architects to speak with about building more sustainable and heatwave resilient buildings.
She has also worked with the City of Parramatta in Sydney on a study looking at the impact of heatwaves.
The council is concerned about the impacts of heat events on people from culturally diverse backgrounds, particularly those that wear a substantial amount of clothing even in extreme heat.
Strategies to overcome heat
Wilson says there are a number of strategies developers and architects can implement in addition to ensuring buildings have backup power. They include installing heat protective screens on glass to cut radiation coming into the apartment, making sure rooftops are light coloured and using louvres or vanes that can be adjusted on windows.
Growing greening on buildings and around buildings is also a good approach, as greening absorbs heat, she says.
Another measure is to develop cool, leafy and shaded common spaces where residents can take refuge from heat and also engage socially to reduce isolation.
However, Wilson says that when developers are operating in Sydney, Melbourne or Brisbane where land is expensive, there may be a reluctance to create these spaces, as common spaces reduce profit margins.
Social housing is a sector where common spaces are more frequently seen, she says.
This has a double benefit, as people in housing for low-socioeconomic groups tend to be more vulnerable to heat impacts generally due to disability, illness or other challenges.
Wilson said that Parramatta Council has found that many older people on low incomes will try and save on airconditioning expenses by going to shopping centres on hot days. The risk is, however, that after having a few hours in the cooler environment, when they exit the centre to return home the heat suddenly hits them. This leads to an increased risk of stroke, kidney disease and other potentially fatal conditions.
Wilson says as well as taking action around the resilience of buildings, there is a need to ensure apartment residents are educated about strategies to manage extreme heat within their homes such as using a wet face washer on the back of the neck, putting their feet in water and ensuring they drink extra water.
More broadly, it is vital to look at the infrastructure around vertical living. There may be a role for planning to require all buildings above two storeys to have back-up power generation, not only for specifically aged or retirement living buildings, but all buildings, given the increasing number of older people living in apartments generally.
“In terms of the policy settings we need to think about it now and do something about it now – rather than in five years time,” Wilson says.
“The evidence [of the risks] is out there. Each year is reported as the hottest year on record – that is true irrespective of if you believe in climate change or not.”
How a retirement living architect approaches climate resilience
Ken Blair, principal of Blair Architects, told The Fifth Estate the reliance on airconditioning was a trend that emerged in retirement living about 20 years ago. Prior to that, fans for cooling and heating were the standard.
When airconditioning was adopted it was from a risk management and amenity approach, and the systems tended to be a large number of individual reverse cycle units throughout a facility.
In terms of contemporary design, he says most architects working in the sector are implementing passive approaches such as living areas being north-facing for winter warmth. Cross ventilation is also a priority.
Back-up power to keep the cooling and other systems running in event of a blackout is being installed by some developments. A recent project the practice worked on in Camberwell installed a gas-fired generator to enable to facility to be grid-independent if required.
There are also “quite a few” installing solar PV panels. As aged care facilities operate with 24/7 power loads, he says panel installations generally have a 4-6-year payback.
Developments are also getting savvy to ways of reducing heat load through design elements such as vertical structures to shield the western sun.
Retractable louvres and externally-mounted blinds or awnings that keep sun off the glass are also valuable.
“We are starting to see that on some apartment developments,” he says.
The problem of heat gain from western sun is not confined to multi-storey buildings. Even if a building is a single storey it still has a problem with the western sun, Blair says.
Greening is also an element he says is important for aged care living and mental health facilities, for the biophilic benefits.
“It has a restorative effect on people.”
His practice’s designs look to incorporate trees in projects wherever possible, he says, especially on the western side as they work well for cooling and shade.
Other important design considerations are that spaces are pleasant places to be and have good views, as aged care is very much about creating an “internal living environment”.
Exposure to landscape and the use of natural materials are important. Balconies and greening in the form of planter boxes can be valuable, however Blair says there can be an issue regarding maintenance.
The practice does a substantial number of projects in regional areas such as Deniliquin and Cobram. He says people in inland areas are “more aware” of the issue of summer heat.
When the temperature doesn’t drop overnight, people take advantage of cross ventilation and other non-mechanical strategies.
Thermal mass from brick or concrete construction is often a problem, as it retains heat gained through the day. Blair says cross-ventilation has been a key strategy for reducing the impact.
How a developer and operator is dealing with climate resilience
Aged care provider HammondCare has got climate resilience firmly on the agenda, including considering the need for back up-power. Michael Cooney, HammondCare general manager property and capital works, told The Fifth Estateit was an “essential consideration”.
“Our residential care homes have back-up generators which automatically take over in the event of a power outage to restore lighting, and in many of our facilities they can also power the airconditioning.”
Last summer, for example, when Western Sydney saw temperatures hit 45°C and grid power failed, all of its residential homes could keep the airconditioning operating.
The impacts of extreme weather conditions are taken into consideration from early in the design process of its developments, he says.
“The orientation of a building is an important factor during site planning and concept design as it will have an impact on cooling and heating inside and out.”
Passive cooling features it looks to maximise during design include seasonal landscape shade, material selection, insulation, window treatments and natural ventilation. At its Miranda site, for example, the buildings feature high corridor ceilings with operable window louvers and plenty of natural ventilation.
Natural ventilation is also considered in terms of how people behave in the buildings.
“People can and will open their doors and windows just like they would at home,” Cooney says.
These strategies have been incorporated into its multi-storey home in Wahroonga, Sydney, and will also be implemented at its new multi-storey development in Darlinghurst that will cater for older people at risk of homelessness.
“The central light well with external terrace spaces is a great example of this,” he says.
The external landscape strategy for its developments include the selection and planting of deciduous trees, generous sized verandas and pergolas to create and utilise shade, as well as external window treatments.
“These design features provide a healthier environment for the resident – but the truth is this is just good design and shouldn’t only apply to aged care homes.”
The organisation also recognises the challenges in older buildings that don’t meet today’s design standards, he says. To mitigate these limitations, common spaces are provided that enable residents to escape extreme heat.
“These spaces provide airconditioned rooms in a relaxed social space and over time these older facilities are being upgraded in line with our modern design standards.”
There has also been substantial investment in renewable energy installations across both its new and existing buildings in recent years.
Cooney says the aim is for its residential homes to meet between 10 and 15 per cent of power needs through solar PV. It is also exploring options for reducing grid dependency further, but this will require changes to how renewable energy is harvested.
“Until battery technology advances further, the amount of renewable energy harvesting is limited,” he says.
“Over the next few years we will see battery technology improve and reduce in cost, and this is likely to be a game changer.”