This post is about research recently featured in The Age that promotes an alternative approach to urban development in Melbourne.  This post also appears on Georgia Garrard’s research blog.

The case for an alternative

Current approaches to urban development in Melbourne focus on low-density urban sprawl and high-density high-rise. In middle-ring suburbs, opportunistic, ad hoc infill is occurring, often with marginal dwelling yields and high impact on amenity. The negative impacts of these types of development on communities are well established. Urban sprawl is associated with high transport and household energy costs, susceptibility to household financial stress, large infrastructure costs, high impact on the natural environment, low walkability, poor access to open space and conflicts with food production. High-density high-rise environments exacerbate the urban heat island effect and are typified by low walkability and inactive streetscapes, and residents experience social isolation and a disconnectedness from nature as a result of poor access to open space. Finally, ad hoc, low yield infill results in changes to neighbourhood character, and the loss of backyards, amenity and biodiversity recreational benefits associated with private open space.

What did we do?

We developed designs and visualisations of an alternative model of sustainable mid-rise development to create healthier, connected communities. We also aimed to create an environment that would re-enchant urban residents with nature and provide the multitude of co-benefits that come with experiences in nature. While the case study presented is Fishermans Bend, this model could potentially be applied to a range of infill sites identified in inner Melbourne and established middle-ring suburbs as well as priority greenfield areas. The design is based on two key principles:

Urban design and building types

Our building types are based on successfully implemented designs from Europe.  Urban design features include:

– Building heights 4-7 storeys to improve accessibility and connectedness to nature and streets.

– Active streetscapes to improve safety and strengthen community (Bain et al. 2012)

– Diversity of building typologies to ensure dwellings for a range of urban residents.

– Incorporating Melbourne’s unique city block and laneway features;

– High quality living spaces, average apartment size 100 m²

Working with nature

Nature in cities has significant benefits to human residents, including improved human health and wellbeing, workplace productivity and childhood cognitive development. Nature also provides numerous co-benefits including cooling, flood mitigation, air and water purification and improved habitat for iconic and threatened species.

In working with nature, we employed a protocol for biodiversity sensitive urban design, which aims to create suburbs that are a net benefit to native species and ecosystems through the provision of essential habitat and food resources. We focused on five native species including birds (brolga & spotted pardalote), a butterfly (dainty swallowtail), a frog (growling grass frog) and a micro-bat (striped free-tailed bat). These species were chosen for their charismatic characteristics (eg. Brolgas are large, spectacular water birds), potential co-benefits (eg. Bats and frogs are insectivorous and therefore help control pests like mosquitos, and butterflies provide residents with restorative psychological benefits), and feasibility of their ecological requirements (eg. Spotted pardalote are already resident in nearby Westgate Park). In addition, the wetlands required by some species provide additional water purification and flood mitigation services in a flood-prone landscape like Fishermans Bend.

Biodiversity sensitive urban design proceeds in 5 steps: 1 Identify and map ecological values (including ecosystems, species, landscape context, historical values); 2 Define ecological objectives (eg. maintain threatened species, restore ecosystem quality, opportunities for re-wilding); 3 Identify development objectives (population size, infrastructure requirements, etc.); 4 Identify actions and resources required to achieve ecological objectives (including habitat and food requirements for target species); 5 Identify urban design that accommodates ecological and development development objectives from steps 2 and 3.

Outcomes

The sustainable mid-rise model achieves housing densities that are comparable to those identified for brownfield development sites in Plan Melbourne.  However, when compared to the proposed high-rise development for Fishermans Bend, the sustainable mid-rise model will provide better urban design and human health and well-bieng outcomes, including better access to open space and improved streetscapes, a reduction in the urban heat island effect, a reduction in household energy use, and improved workplace productivity and childhood cognitive development.

Density    We achieved net housing densities of between 200 and 310 dwellings per hectare, assuming average apartment size is 100m². This is comparable to densities required for many brownfield development sites, as identified in Plan Melbourne.

Activated streetscapes    In contrast to the standard tower & podium model, building frontages are residential, mixed with office spaces and commercial use on the ground floor. High diversity of street types, including laneways and vegetated boulevards, provide improved connectivity.

Open space    100% dwellings are within 2 minutes walk of at least one green open space. Open space is a mix of large shared areas and smaller semi-private courtyards.

Cooling    Vegetated landscapes are up to 4 degrees cooler on the basis of City of Melbourne urban greening temperature modelling.

Household energy use   Operational energy use of midrise apartments is up to 45% lower per dwelling than that of high-rise apartments.

Childhood cognitive development   Numerous recent studies have connected the provision of biodiverse green open space to significant improvements in childhood cognitive development.

Workplace productivity   Evidence demonstrates that integrating nature with workplace design reduces stress and increases productivity. For example, a recent study showed 6% increase in productivity of employees who have a view of nature compared to those who have no view.

Policy implications

To move towards the sustainable mid-rise model presented here, we need:

• better strategic identification of appropriate development sites;
• a tweaked policy environment including some alterations to current zoning to allow residential and mix-use development in sites currently zoned commercial and industrial;
• a shift in the built-form/design typology of current practice. This could be achieved through changes to precinct plans, planning schemes and design guidelines; and
• Better integration of planning and biodiversity. Changes to the planning scheme that mandate urban greening are required, as are policies that explicitly link urban greening with biodiversity.

This blog presents initial findings of research funded by The Myer Foundation. Entitled ‘Reimaging the Suburb’, this work seeks to identify alternative urban forms for Melbourne that protect biodiversity, while creating liveable, healthy, connected communities. Please don’t hesitate to contact us with for further information.

Georgia Garrard georgia.garrard@rmit.edu.au  Sarah Bekessy sarah.bekessy@rmit.edu.au

Acknowledgements  This blog post represents the work of many individuals.  Simon van Wijnen did the urban design and video fly-through. Graphic representations fo individual scenes were produced in consultation with Mauro Baracco, Catherine Horwill, Jonathan Ware (RMIT School of Architecture and Design).