While the density of urban development intensifies to accommodate the influx of people living and working in our cities, the demand for urban green space also grows.

Increasingly, we’re giving up our bucolic lifestyles and sprawling private gardens to live and prosper in urban centres, yet the desire to unwind in soothing green surrounds remains. Regrettably, in the process of creating these concrete powerhouses – squeezing the multitude of needs into a finite amount of space – we underestimated the ability of plants and green infrastructure to sustain so many of the environmental, social and economic functions that enable places to thrive.

Given the complexity of the environmental challenges we now face – locally, nationally and globally – our approach to urban development must continue to evolve to better support, and leverage, the essential natural processes that are so vital to a sustainable future. We need to continue to develop fresh perspectives and take a more holistic approach to the urban landscape – to revive and reconnect our green space and systems.

As a design response, well-integrated green infrastructure is key to restoring this city balance, and green roofs are one area of focus with the ability to defy the existing spatial limitations and deliver abundant benefits.

Burnley Living Roofs
[Photography by Peter Bennetts]

Urban roof top sanctuaries with expansive views are just the beginning of the big-picture payoff. It is also widely accepted that green roofs can cool the urban environment and reduce energy consumption, improve air and water quality, and mitigate flooding, while increasing and connecting urban habitat to support biodiversity; all of which contribute to healthier urban ecosystems. Collectively, this makes a solid case for expanding their place in the urban environment.

Though green roofs are far from a new concept, they’ve been slow to take hold in many developed cities. Any flight over an urban area will reveal an expanse of tin roofs, cooling stacks and plant overruns amongst concrete and tiles. One would be forgiven for thinking that the idea of green roofs is reserved for elite apartments and select infrastructure, but this need not be the case.

A major impediment to the wider implementation of green inner city and industrial roofscapes has been a lack of scientific data to evaluate their applicability across a range of climates, but this is rapidly changing. The broadening scope of leading academic research in green infrastructure technology and urban horticulture is now delivering the evidence to support the efficiency of green roofs in a wider variety of contexts. Contemporary green roof projects, such as the University of Melbourne’s Burnley Living Roofs combine pioneering horticultural research with leading landscape architectural design and specialised construction expertise. Collaborations like these can produce truly innovative green roof solutions that reach far beyond the obvious aesthetic and restorative aspirations to deliver exceptionally habitable, diverse and productive rooftop spaces.

Increasingly, major cities around the world are recognising the value of green roofs as a viable strategy for climate change adaptation and are encouraging their widespread implementation to help meet green targets. Singapore, for example, established the Building and Construction Authority’s (BCA) Green Building Master plan in 2006 to guide and incentivise both old and new developments to ‘go green’. Ten years on, the impact is highly visible throughout the city – with abundant green walls, roofs, significant sky gardens and elevated recreation zones.

In 2015, France passed a law that requires all new commercial buildings to be partially covered with either plant material or solar panels; and there are numerous other countries and/or cities following suit – targeting the ‘fifth elevation’ of our buildings as a key area for addressing energy and pollution challenges through green infrastructure. Such changes in our approach to the built environment, supported by government targets, policy, law and convincing research data will ultimately help create more sustainable, liveable and beautiful cities for our future.

As designers, the physical evidence and research data are now readily available to push for living architecture and get the development sceptics on board. Though research analytics aside, it’s our new urban communities that are demanding more. Many projects around the globe, through community uplift, engagement and market expectation, are making use of city roofs for everything from urban farming and community agriculture, to playgrounds, schoolyards and outdoor learning environments, to purely restorative open garden space for residents, visitors and workers alike – all as an alternative to the traditional ground-level offering.

New York’s Brooklyn Grange for example, is a rooftop urban farm, a community green space, an education centre and social enterprise in one – offering a year-round calendar of community-based activities. Ranging from bee keeping and yoga classes, to weddings, cocktail parties, lunches and youth activities to the production of 22,500 kg of home grown produce per annum for the local community and participating local restaurants.

Brooklyn Grange

The Harbour Family and Children’s Centre is located on the rooftop of the largest supermarket in the Melbourne Docklands. Providing spaces for 150 children from infant to five years, the centre aims to establish a benchmark in showcasing Lady Gowrie’s vision for outdoor play as a fundamental aspect of early childhood development.

The courtyard is a diverse and tactile series of nature-based play spaces that provide a backdrop for the facility’s learning programs. Incorporating sandpits, digging and water play zone, kitchen garden and a flexible-use softfall areas, the gardens vary in theme to showcase the diversity of the natural world. This unique learning environment, above the streets of Melbourne, is an important addition to community infrastructure within a fast-growing high-density commercial and residential precinct.

With evidence in hand and increasing community expectations, it is encouraging to see the shift of policy makers now working together with the landscape architectural design community – embracing opportunities to contribute on a ‘higher plane’ and support the collective health of urban communities through elevated green space and expanded green infrastructure for all.