A record-breaking summer heatwave, urban densification along the Northbourne corridor, concerns over rising energy prices and housing equity, and a vision for a carbon-neutral Canberra.
The common denominator in the above? The need for sustainable living space that increases comfort and affordability for Canberrans.
The ACT is expected to grow faster than Australia as a whole. Our population will likely be about 500,000 in 10 years, and 600,000 by 2045 or earlier. More people means more demand for housing, infrastructure and transport services. How and where this living space is provided will have long-lasting effects on the city and its citizens.
Just how long-lasting? The Green Building Council of Australia estimates that more than half of the homes standing in 2050 will have been built after 2019; the rest will be the homes we now live in. All of this housing, new and existing, needs to be suitable not only for the Canberra of 2020 but the Canberra of 2050.
Given the ACT is committed to achieving net-zero emissions by 2045 – with interim targets along the way for 2020, 2025, 2030 and 2040 – we must improve our housing's energy use and efficiency as we develop and refurbish this building stock. We must also ensure that building standards are suitable for a hotter, more extreme climate, so as to provide us with comfortable living.
Improved energy efficiency is a win-win solution for new housing stock, and the cheapest way to provide comfort, savings and emission reductions. Unfortunately, studies by the CSIRO and Curtin University researchers show that Australian building standards and new residences are woefully behind those of many other developed countries in providing thermally well-insulated and airtight homes.
Australia's energy ministers, through COAG, are expected to work on improving energy-efficiency standards for the 2022 national construction code. But every year of delay locks in increased energy costs, carbon emissions and unnecessary discomfort.
The ACT could lead the way by setting a bar now that is higher than current national building standards, thereby locking in comfort, affordability and sustainability of Canberran homes for decades to come. We also have an urgent need to monitor frequently whether standards are implemented, given the massive development activity under way in this city.
But it isn't just individual buildings that need careful attention; equally important is their relationship to one another and the spaces around them. Increasing Canberra's population density can reduce infrastructure costs and travel distances. But unless it is properly considered it can also lead to the loss of cool, green, recreational space and an increase in the urban heat-island effect.
Urban areas are often a "hot island" in the middle of cooler surrounds because urban buildings and paving absorb the sun's heat and release it slowly during the night. This makes both day and nighttime temperatures hotter in a city than they would otherwise be, exacerbating heatwaves caused by climate change. This is detrimental to human, animal and vegetation health.
A recent CSIRO report shows that built-up areas in Canberra are, on average, 8 degrees warmer on summer nights than surrounding rural areas. The most-affected areas are those with large expanses of paving and rooftops, and few trees – an unfortunate feature of Canberra's newest housing developments and the increasingly high-density living and working spaces near the city's centre.
A guideline for any new development, urban renewal or revised plan should be that the urban heat-island effect is reduced, not increased. In areas of higher population density, this means more green space, not less. This improves amenity and livability, too: more people in a smaller area require more green space in their immediate surrounds.
Canberrans increasingly rent rather than own a property. Equity in housing outcomes is essential to a healthy, diverse city. Renters deserve the same energy efficiency and climate comfort as home owners. Tenants live in the space and pay the energy bills, but have little incentive to install energy-efficient features for a property in which they have no equity. Studies have shown that rental properties have substantially lower energy-efficiency ratings than properties offered for sale.
One way to level this playing field would be to require that all rental properties in the ACT disclose recent, detailed, independent, energy-efficiency-rating assessments upon advertisement and in the lease. These could be accompanied by a government-approved estimate of the effect of the rating on energy costs. In this way, Canberrans who rent could make the same kind of informed decisions now available to property buyers, and landlords would have an incentive to improve their properties' liveability, efficiency and value.
The common goal across all these initiatives would be to maintain and improve Canberra's status as a liveable, sustainable and equitable community, which benefits us all.
Penny D. Sackett, a former Australian chief scientist, is an honorary professor at the Australian National Univeristy. She is also deputy chairwoman of the ACT Climate Change Council, an independent statutory body that advises the ACT government on climate change. This is the fourth in a series of articles exploring how Canberra can transition to carbon neutrality.