To celebrate National Tree Day, Sweltering Cities spoke to Barbara Schaffer, Principal Landscape Architect for GANSW (The Government Architect NSW), about designing liveable cities that ensure the health and wellbeing of communities. Barbara’s role involves guiding policy and advocacy to enable landscape architects to positively contribute to healthy, resilient and sustainable places.
As a landscape architect, what does the term sustainable cities mean to you?
There are a number of things that come to mind. The first thing is a respect and understanding for natural systems within our cities. So that our rivers and creeks, our national parks, our nature reserves, our existing green space are considered at the outset in the design of our cities.
Examples of green spaces (2022)
It means ensuring that anything we do from the outset takes those elements into consideration with a considered understanding and a respect for place. This includes our Indigenous history. We need to instill a deep respect for and Connection to Country. This involves consulting with Traditional Owners at the outset as well as ensuring that there is an adequate amount of green space, that there’s equity of access to green space, that there’s a sufficient amount of green cover and tree canopy to connect our natural systems with our planned and designed public spaces. Also, that water is used sustainably, that there’s a consideration for water sensitive urban design, so that stormwater is managed in a way that it doesn’t just pollute, but rather is used in a way that can be cleansed before it runs out into precious natural systems.
What are the elements that go into the design of a sustainable city?
Sustainable cities are not just about natural elements, but also the built elements. Sustainability for me is also about encouraging walkability, so that people can access cities and move around cities and are not so car dependent. Public transport, adequate shade at bus stops, adequate shade along our street networks, making sure that our streets can actually accommodate trees.
It’s not just one thing. It’s the relationship between the built environment and the natural environment, the urban design, all the parks and public spaces in between that enable people to congregate, and to encourage social cohesion, because that is also an incredibly important element of a sustainable city, that people can come together.
Is there a specific project that you’ve worked on that focused on increasing green space in a specific area?
I’ve been involved in a number of projects, but one of the key projects that I’ve been involved in within the New South Wales government was the Green Grid, which was a strategy to create an interconnected network of open space across metropolitan Sydney. So before we even began that project, we mapped all the existing green space with the then 52 councils across metropolitan Sydney, and then we did an audit of green space. One parameter we used was ‘everybody should be within 400 meters of an existing green space’, and so we were able to map where there were deficiencies in open space.
In that way, we were able to encourage councils to look at where they needed to increase green space. The idea is to create an interconnected network of open space; to connect our creeks and our rivers and our parks through our streets and infrastructure corridors.
The Green Grid project was taken up and included in the Greater Sydney Regional Plan, so it had a directive from the highest strategy planning level. Councils were required to include green grid strategies in their local strategic planning statements. So in that way, there is a link at the highest level of strategy down to local strategic planning statements and council’s local environment plans.
The principles associated with the green grid strategy are ensuring equity of access to open space, ensuring that we green our networks, so that there’s urban greening to address important issues like urban heat. I think that that strategy has had a far reaching impact.
What do we overlook about trees when it comes to designing sustainable cities?
That there are not enough trees. In the West and in other parts of Melbourne, when new suburbs are designed, there isn’t enough space on the pavements for trees.
Aerial image of Werribee, Victoria showing low levels of tree cover (2021)
I think that what we need to do is retrofit, and most importantly you need data for this. I think that in Melbourne there’s actually good data, and with the sort of GIS data (note: GIS is a software that creates and maps data) that we have today, you can map heat, and canopy cover, and you can see the areas where there is deficient canopy. Where it’s hottest often relates to where there is not enough canopy, and these are the areas that we need to target. We need to target our most disadvantaged areas, and our decisions need to be evidence based.
When it comes to trees, designing liveable cities is about ensuring that there’s sufficient space and that trees aren’t spaced too far apart. This is so we can enjoy the shade and beauty. We also need to take into account geology and rainfall, to ensure the right trees are in the right place.
How can we heat proof our cities to create more liveable suburbs?
It’s a systems approach. I don’t think that it’s a silver bullet using one thing. Urban canopy is essential. Not only do trees provide shade, but they provide evapotranspiration as well as creating beautiful places. Trees are critical, but I think it’s also about looking at white roofs, for example. In a lot of new developments, they’re using black roofs, which attract heat. I think it’s also about water sensitive urban design, and how we use water in the landscape. For example, fountains, bubblers and misting sprays.
Aerial image of Caddens, NSW, showing rows of houses with black roofs (2023). Getting rid of dark roofs in Sydney could lower the city’s temperature by 2.4°C
Reducing heat in our cities is a multivalent approach. It’s not just one thing. It’s about looking at a range of strategies collectively, including looking at housing. What you find is that
The lowest socioeconomic groups have the lowest amount of green cover, the least access to parks, and the built form is done in a way that is the least sustainable in terms of insulation.
It is very much about adopting a systems approach. The Green Grid is about understanding the city as a system, understanding the hydrology, the ecology and the recreational aspects. And when we are addressing urban heat, we need to look at it from a number of vantage points if we are serious about addressing heat in our cities.
When it comes to green space, we need to ensure that there is sufficient canopy within it. We’ve set a target of 40% canopy cover over metropolitan Sydney, with different targets for a range of development typologies, commercial, residential, industrial.
There’s a fabulous document which has been produced by the NSW Department of Planning which is called the Greener Neighborhoods Guide which detailed targets for urban Canopy.
It’s not one size fits all. Each response has to be a place based response.
We’re heading into an El Niño and this summer is set to be a scorcher. What should be the top priorities of governments to prepare for the heat?
What we need to be focusing on is heat and health.
Coming out of COVID, we understand the health benefits of public open space. Health and heat needs to be at the forefront of all our planning considerations.
Climate change is a real issue for landscape architects. What we’re looking at really is climate and biodiversity. We’re looking at ensuring that there’s dedicated green infrastructure. It’s about creating healthy communities, liveable cities, to contribute to people’s physical and mental well being.
Creating interconnected networks of open space, as was done in the Green Grid, and setting canopy targets will contribute to creating more sustainable and resilient communities.
Green infrastructure is an interconnected network of open space that includes our parks, our rivers, our streets, that support sustainable communities, and includes waterways, bushland, tree canopy, parks, open spaces, that are strategically planned and designed, and manage to support a good quality of life in the urban environment.
On a local level, what advice do you have for local communities who want to create more heat resilient neighbourhoods on a local scale?
I think tree planting and bringing our verges to life by removing grass monocultures and planting diverse flowering native plants and lobbying your councils. A lot of councils do have tree planting and verge garden initiatives. In my area, I’m running an environmental collective called TreeRites, which enables the general public to plant tiny forests, to celebrate and commemorate rites of passage. One of the initiatives that I’m trying to get up is for every kindergarten child, as part of their rite of passage through school, will plant a tiny forest in a local park within five minutes walk of their school. This will become known as the children’s forest.
How are you celebrating National Tree Day?
For School’s Tree Day, as part of an environmental collective that I initiated called TreeRites, we’re working with 75 children from two preschools, who will be planting a tiny forest to celebrate their transition from preschool to kindergarten. They will be planting 300 locally sourced Indigenous plants. The intention is to enable these children to develop an understanding of nature, a love of nature, and in that process learn about the importance of trees and habitat. We are planting hope! This project has been funded by Planet Ark in alignment with Schools Tree Day.