PURPOSE
To seek that the Federal Government co-ordinate changes to current planning policies that create extensive urban heat islands with up to 12° higher temperatures compared to adjacent rural areas to policies that are properly climate resilient, with the planning processes in Canberra being used to illustrate the problem.
ACT Planning Creates Extensive Heat Islands
In its ACT Planning Strategy 2018, the ACT Government set a development target of 70% within the existing urban footprint, stating urban density needs to be balanced with a natural environment, green spaces and trees
However, as noted below, the ACT Planning process focuses on intensive high-rise development in the ACT at the expense of separate low-rise residential development creates extensive urban heat islands with higher temperatures compared to adjacent rural areas.
According to the US Environmental Protection Agency (EPA):
“The term “heat island” describes built up areas that are hotter than nearby rural areas. The annual mean air temperature of a city with 1 million people or more can be 1.8–5.4°F (1–3°C) warmer than its surroundings. In the evening, the difference can be as high as 22°F (12°C). Heat islands can affect communities by increasing summertime peak energy demand, air conditioning costs, air pollution and greenhouse gas emissions, heat-related illness and mortality, and water quality.”
Urban Heat Effect has become an international problem with Australia on of the countries singled out for mention in the 28 February 2022, the Intergovernmental Panel on Climate Change:
“From Australia to Africa, from mountains to the deep sea, the impacts of climate change are widespread and varied, affecting up to 3.6 billion people today who are considered to be living in climate hotspots across the globe. That’s nearly half the world’s population”.
The report stresses the need to reduce climate risks sustainably and achieve resilience - reduce human-induced greenhouse gas emissions drastically and transform our way of life fundamentally. This includes planning cities cooled by parks and ponds, greening not only city streets but building rooftops and walls.
ACT Planning Unduly Focused on Intensive Development
The ACT Government has also ignored the principles set out in the ACT Spatial Plan which incorporates key principles for making the ACT Climate resilient including its goal to provide Canberra’s urban footprint with the equivalent benefits of a 30% tree canopy cover and 30% permeable surface.
A prime example being turning projected office buildings in Gungahlin into flats and the intensive development along Northbourne Avenue in order to justify the high cost of light rail. The paper Transport for Canberra – http://www.cbchristensen.net/papers/2014/12/05/tunnel-vision-light-rail.html — is not
“just about creating a Frequent Network consisting of high density transport corridors … it is ultimately about re-engineering all of Canberra… “(T)he ACT Government’s new planning strategy … outlines an approach to creating a more compact and sustainable city by concentrating new development along transport corridors defined in the Frequent Network.”
At this point, we see that Transport for Canberra envisages a truly fundamental transformation of Canberra’s urban form in which “increased density will help support more efficient public transport as well as vibrant neighborhood centres”.
As referred to above, as well as ignoring ACT Community aspirations and planning principles, this intensive development ignores the IPCC report on heat islands. Such masses of concrete of high-density housing forces people to use air conditioners exuding hot air, producing a vicious cycle.
However, even the ACT new “roofscape” suburbs are also extensive urban heat islands, with large houses squeezed onto small blocks, roofs almost touching adjacent roofs and the rest covered in concrete driveways and little grass, usually synthetic often. Such new dysfunctional suburbs are not limited to the ACT but afflict all major Australian cities.
In Canberra they are taking on the form of a choking collar around the inner older suburbs. Unfortunately, there is no way to remedy the situation as there’s just no space for planting large trees, therefore no canopy cover to cool the area let alone support any wildlife.
The Queanbeyan Palerang Council has recently produced a Surface Heat Mapping Report Keeping it Cool - Vegetation and Heat Adaptation Strategy’ - Queanbeyan-Palerang (nsw.gov.au).
Sydney suburbs have already reached temperatures of over 50 degrees (Penrith: Temperatures hit over 50C last summer | news.com.au) with fatal consequences for some. Canberra's 2017 Report urgently needs updating to demonstrate the effect of such high-density developments.
Good Intensive Development is Achievable
Director of Canberra Town Planning, Kip Tanner is in favour of balanced high-rise development, noting the world’s most livable cities aren’t packed with people – but neither are they sprawling suburbs in search of a city.
Kip says that Canberra in the 1960s had a higher density than now.
“In 1966, when Canberra consisted only of the Inner North, Inner South and the first few suburbs of Woden, the population of Canberra was 96,000. By the 2001 census the population of this area had dwindled to just 74,000, generally attributed to a reduced number of people per dwelling. By 2011 the population of the same area had climbed back up to 83,000, but was still less than the 1960s. The population is returning with the development of smaller dwellings in the inner areas to cater for our smaller family units.”
He notes that:
Canberra currently has a population density of 173 people per sqm, considerably less than Sydney’s 400 or Melbourne’s 453, but more than Brisbane’s 145 or Darwin’s 44 per sqm.
Mumbai has 29,650 people squeezed into each square kilometre which is totally unacceptable.
More livable cities include Copenhagen with 816 people per square kilometre, Berlin at 984 and Paris at 2,723.
Dense development can create vibrant streets with busy shop fronts, parks and squares alive with people and activity, and an interesting and intriguing mix of building types.
He acknowledges that while density for density’s sake isn’t necessarily beneficial:
“However, if increasing density allows more people to live close to employment opportunities and services, but also provides amenity in terms of open space and community facilities, then it can result in great outcomes…on the other hand… “Families still need large and flexible homes, access to playgrounds and somewhere to play footy, but they don’t necessarily need a huge block of land. People downsizing still need space for visiting families and grandchildren, and they don’t necessarily want to live in a tiny apartment. Most people want to be able to walk to the local shops. What we really need are housing choices that cater for everyone’s needs.”
Elisabeth Judd, a Director at JUDD.studio, says that density in Canberra should be tailored to reflect and enhance the unique Canberra planning context.
“Density doesn’t have to be a dirty word and it can mean different things to different people. High density in Canberra would probably be considered medium to low density in Sydney or Hong Kong. What’s important is achieving the right building typologies in the right places to enhance our lifestyles, and to build a Canberra that will be right for right now and for future generations too.”
“Canberrans are discerning and proud of our city. Bigger buildings have a bigger impact, so new density needs to create great internal spaces and contribute to an exceptional streetscape. There’s a real opportunity too for new development to contribute to quality spaces between buildings and on-the-ground connections to make for a positive and sustainable lifestyle.”
“We should be setting an example in terms of offering diversity in Canberra. New development should create space not just for the wealthy but for people looking for more affordable living options and small or start-up businesses too”.
Pieter Van der Walt, also a director with Canberra Town Planning, says he was surprised by the city’s low-density when he arrived in 2003. “Canberra was more sleepy country town than world city,” he says, “But over the year, key pockets of density have delivered a “richer and more vibrant cityscape”.
“We are increasingly becoming a city with a diverse and layered population that wants more choices than low density, townhouse and simple apartment housing choices. Density provides the opportunity to re-imagine how we live, how we play and how we interact with the city.”
Pieter goes on to say that densification enhances sustainability, active and public transport opportunities, and more efficient use of land and resources and densification in key locations can help preserve low-density housing in other parts of Canberra.
He concludes:
“I think we live in an interesting time in the history of the city where we get an opportunity to be part of the character change from the historically low-density administrative centre to a vibrant, diverse and modern city.
We have a unique setting with unique landscape features that can be leveraged and re-imagined as a canvas to create the future Canberra for generations to come. It’s a big responsibility in terms of the future of this city but an exciting prospect all the same.”
ACT Solution to balance Intensive Development already exists
In other parts of the world where the effects of high-density housing have been studied for decades like Japan, the problem is alleviated with satellite towns. This should also be the answer for Canberra such as envisaged in the 1967 Y-Plan.
The 1967 Y-Plan provided for Canberra to grow through the creation of separate districts in the form of a ‘Y’ (see figure on following page).
The Canberra Spatial Plan departs from the Y-Plan in key areas by seeking to provide a more sustainable and compact city form. However, the ACT Government emphasised that The Canberra Spatial Plan “does not resile from the multicentred model of the Y-Plan, nor ‘undo’ it”.
Unfortunately, the ACT Planning process focuses on intensive high-rise development in the ACT at the expense of separate low-rise residential development creates extensive urban heat islands with higher temperatures compared to adjacent rural areas.
Making the ACT Climate Resilient
The ACT Government needs to abandon its light rail centric planning focus and return to principles set out in The ACT Spatial Plan which incorporates key principles for making the ACT Climate resilient.
Higher density residential development will be promoted within the existing urban area, providing easy access between home and places of work, education, community services and cultural activities. Primarily this increased development will occur in Civic, along Northbourne Avenue, Constitution Avenue, in Barton and Kingston and around the town centres with limited change to existing suburban areas. People will enjoy a choice of housing type and location.
It also needs to follow the following key precepts if its goal to provide Canberra’s urban footprint with the equivalent benefits of a 30% tree canopy cover and 30% permeable surface.
1. Light-coloured Concrete & White Roofs
Black and dull colors absorb huge amounts of solar heat, resulting in warmer surfaces, while light-colored concrete and white roofs reflect up to 50% more light and, in cutting down the ambient temperature, reduce overall air conditioning demands, as well as the urban health island effect.
2. Green Roofs & Vegetation Cover
Green roofing - planting vegetation on roofs – lessens the impacts of urban heat islands because plants are excellent insulators during summer, decreasing the overall urban heat island effect. They also cool the surrounding environments, reducing air conditioning demands and costs.
Plants absorb carbon dioxide improving fresh air quality in green roofing, open space planting, street trees and curbside planting.
3. Planting Trees in Cities
Tree planting within and around cities effectively reflects solar radiation while decreasing the urban heat island effect. Trees absorb carbon dioxide, release oxygen and fresh air, and provide a cooling effect. Deciduous trees are best suited for urban areas because they provide a cooling effect in summer and don’t block warmth during winter.
4. Green Parking Spaces
Green parking spaces utilize strategies to limit the impacts of urban heat island effect. The largest feature of the parking lot is its paved area so, by changing this surface to be more permeable to water the parking lot will drain better. Some surface options are open joint pavers, porous pavers/asphalt or a turf grid cushion against the elevation of pavement temperatures reducing the impact of lessens the impacts of urban heat islands as well as preventing pollution in stormwater runoff. With this in place, the danger posed to aquatic systems is reduced.
5. Education and Sensitization of Heat Reduction Policies and Rules
The ACT Government needs to ensure that education and outreach programs are put in place to ensure that the community is aware of the economic and social benefits of all environmental policies such as such as planting trees and eco-roofing. These, together with other initiatives already in place such as the uses of renewable energy, and clean car rule standards will impressively regulate the anthropogenic inducers of urban heat island effect.
With fewer emissions, the level of greenhouse gases in the atmosphere can be reduced, thus decreasing the effects of climate change and global warming.
Albert Oberdorf
Canberra July 2022