Our Research
Engineered Spaces for Trees in Paved Areas
Urban trees and tree canopy cover are increasingly recognised as essential components of the cities and neighbourhoods where more than 90% of Australia’s forecast population of 35 million will live by 2050.
International research and practice, to date, has responded to the challenge of sustaining multi-functional, large, long-lived trees within compact forms of development, amongst paved plazas and alongside roads and streets.
A range of techniques have been advanced that are capable of delivering adequate quality and quantity of space for tree root growth while maintaining pavement functionality, including: structural soil; soil filled load-bearing cells; suspended slab pavement along with permeable pavements.
Applications of these engineered surface and subsurface tree spaces in Australian cities has occurred over the last 20 years. However, their use has been limited, rarely monitored and is often perceived by developers, infrastructure authorities and local governments as a high cost, high-risk approach.
Yet these same stakeholders are increasingly attentive to the opportunities that green infrastructure components offer to community health and well-being, tourism, business vitality, property value improvement, place making, buffering urban microclimate, managing local stormwater, air quality improvement, and so much more.
This national study proposes a range of monitored, long-term trials in Australian cities to advance best practices and build knowledge sharing. Complementary qualitative research is also proposed to explore the barriers to implementation and to collate the learnings from existing installations of surface and subsurface tree spaces.
TREENET, as a reputable, independent non-profit organisation dedicated to improving the urban forest, sees facilitating this special research project as critical to building home-grown evidence to support those designing our cities for trees.

In seeking to refine the scope and methodology of the ‘National Trials Project’, develop cost estimates and source funding opportunities, TREENET is engaging with key stakeholder groups in order to progress best practice in designing and maintaining engineered spaces for tree growth in paved areas in Australian cities.
Interest continues to be sought from research organisations, industry associations, product manufacturers/distributors, product user groups (eg. local government, landscape architects, urban designers, construction companies) and potential trial site stakeholders.
Check out the following resources which have been extracted from TREENET’s significant collection of academic papers and case studies:
Meeting the challenge of managing tree roots & infrastructure
Trees in Hard Landscapes – Trees & Design Action Group (TDAG)
Examples of existing experiences can be explored via the Case Studies Portal.
The influence of urban canyon microclimate and contrasting photoperiod on the physiological response of street trees and the potential benefits of water sensitive urban design
Street trees play an important role in helping cities to adapt to multiple environmental perturbations resulting from urbanization, such as changes to the urban water cycle…
Impacts of enhanced storm water infiltration on urban Melia azedarach functioning in dry season
In the face of ongoing climate change and rising human populations, the health of urban green spaces and management of natural resources have become increasingly important…
Catchment Hydrology – Before & After WSUD Treatments
Hussain’s Masters degree research included detailed analysis of a stormwater sub-catchment in Hawthorn, a southern suburb of the city of Adelaide in South Australia. The analysis determined the catchment characteristics which influence stormwater discharge from the 17 hectare catchment, which was retrofitted with over 180 TREENET Inlets in two stages over a two year period…
Irrigated greenspace – improving the liveability of towns and suburbs
During the 2019/20 irrigation season, SA Water undertook a trial, using smart hardware and software technology to ensure that open space irrigation is both efficient and effective…
Collaborative Approach to Green Engineering
TREENET supports research and knowledge sharing to better integrate trees into cities. Since it began in 1997, TREENET has collaborated with industry, government, research and educational institutions to progress Australian urban forestry. The understanding that trees are fundamental assets which support healthy and resilient communities is now more widespread due to TREENET, to similarly focused agencies worldwide and to global awareness and concern regarding climate change and urbanisation…
Engineered Spaces for Tree Growth in Paved Urban Areas – TREENET National Trials Project Update
As part of the Project goals to encourage the uptake of innovative engineered spaces for growing healthy, longlived trees in paved urban areas, TREENET now offers…
WSUD – Research to Applied
Harsha Sapdhare, PhD Student, University of South Australia Tim Johnson, City of Mitcham David Lawry OAM, Space Down Under Abstract TREENET’s focus from its inception
Trees and permeable paving: future symbionts
Tim Johnson City Of Mitcham & University Of South Australia Introduction In 2009 the City of Mitcham retrofitted twelve permeable pavement sections and tree planting
Council Verges as the Next Wetland – The City of Salisbury and TREENET Working Together
This paper details water sensitive urban design (WSUD) in practice in the City of Salisbury including the TREENET inlet system…
Trees as essential infrastructure: Engineering and design considerations
Simon Beecham School of Natural and Built Environments and Centre for Water Management and Reuse University of South Australia [email protected] Abstract One of the guiding
Best practice design and implementation of urban tree planting – Victoria Avenue Pedestrian Mall upgrade, Chatswood NSW
Arterra Design is a professional consultancy specialising in landscape architecture, site planning, consulting arboriculture and water sensitive urban design. Our mission is to design, communicate and construct memorable places that are creative, elegant, functional and enduring…
Permeable Pavements and their Influence on Tree Growth of Melaleuca quinquenervia – A Summary
Population centres are changing from rural to urbanised areas, with increasing development to create supportive infrastructure…
Using Water Sensitive Urban Design to Green Our Streets
Robin Allison, Director DesignFlow Water sensitive urban design (WSUD) is a means of using water to mimic natural process of retaining, filtering and infiltrating stormwater
An investigation of the potential to use street trees and designed soils to treat urban stormwater
In recent times, a greater emphasis has been placed on the environmental aspects of urban stormwater management. An experiment has been designed to investigate the potential of using street tree and tree soil systems to treat stormwater…