The Western Australian Government can save billions of dollars in infrastructure costs through a focus on sustainable infill development in Perth, a new report has shown.

The #designperth study, a collaboration between Greens Senator Scott Ludlam, the Property Council of Australia, CODA Architecture and Urban Design, and Curtin University Sustainability Policy Institute, shows the government saves $94.5 million for every 1000 infill lots developed compared with the costs of developing new greenfield sites.

Building on the 2013 Transforming Perth study, it analyses the cost to government and individual households of both kinds of development. The data showed that the cost to government to provide infrastructure including roads, water, communications, power, health, education and emergency services in greenfield sites was $150,390 a lot, compared with $55,830 in infill sites.

WA Greens Senator Rachel Siewert said that if the city increased its infill target from the current 47 per cent to 60 per cent, by 2050 $23 billion could be saved – enough to pay for the Perth Light Rail network 12 times over.

The analysis also shows that greenfields developments result in an additional $6600 a year on average in costs for Perth households due to extra travel costs, and cost the broader economy $1400 a lot per year in environmental, health and productivity costs.

The authors examine the roadblocks that currently exist, including lack of long-term certainty and planning for infrastructure delivery, and a focus on short-term gain rather than a whole-of-life assessment of costs that incorporates the value of good design.

Some of the state and local government planning rules, including mandatory parking provisions, are also highlighted as problematic.

The report also examines some of the design elements required to deliver liveable, sustainable and connected infill communities.

A “design charrette” process was carried out with eight of Perth’s leading architecture and urban design firms involving eight identified infill sites. The report outlines the possibilities for three of those sites – on Ranford Road, Great Eastern Highway and Wanneroo Road.

The case study designs and planning produced by CODA, Cox Architecture and Donaldson + Warn include provision of public open space, reducing car dependency, activating the ground plane, greening and integrating commercial and social elements.

CODA Architecture and Urban Design director Kieran Wong said clever design was important not only for the occupants or users, but for the wider community.

“This report outlines a vision for Perth that utilises design thinking and expertise to leverage greater outcomes for communities on key infill sites across the metropolitan region,” he said.

It imagined “a more vibrant people oriented delivery of density”.

“This is not simply measured in number of people per hectare, but in quality and access to social and public amenity and infrastructure.”

Ms Siewert said the designers’ work showed that designing new developments as “precincts” created 352 per cent more local jobs and commercial floor space, 187 per cent more public open space, 739 per cent increase in public transport use, and significantly more housing diversity.

“Households also benefit from 60 per cent less energy and 70 per cent less water in well-designed medium density housing, saving them up to $1200 in power and water bills a year, which significantly improves the quality of life for low income earners,” Ms Siewert said.

The Property Council’s Western Australia executive director Lino Iacomella said growing strong and prosperous communities in Perth required “creative and diverse design principles for buildings and places”.

“#designperth is a powerful demonstration that in a rapidly expanding city like Perth we can achieve more growth through greater housing diversity, including infill development,” Mr Iacomella said.

One of the report’s authors, CUSP’s Professor Peter Newman, said the report underlined why Perth needed to increase its proportion of infill to remain a competitive, liveable and sustainable city.

“Every state government in Australia wants more urban regeneration including WA but we are lacking ways to make it happen better. This report sets out some great examples and some obvious policy support that is needed,” he said.

Australian Greens leader Richard Di Natale said it made economic and environmental sense for Perth to be planned in a new way that embraced a connected and sustainable vision.

“This report imagines a city where we leave our cars behind, travel on public transport to the doctor or the shops and results in reduced air pollution, which is better for our health and the environment,” he said.

“It’s a holistic approach that saves millions of taxpayer’s dollars and mitigates 4.4 tonnes of carbon pollution per house per year. What a wonderful vision every Australian city could embrace.”

The authors conclude with a number of recommendations, including that the state government re-establish a Sustainability Policy Unit within the Department of Premier and Cabinet, “with its first task to revise the abandoned State Sustainability Strategy with a more strategic approach that prioritises transformative actions that lead to sustainable outcomes in decision making processes”.

Other recommendations include the introduction of a State Planning Policy for Design Quality, reforms to the Strata Titles Act, establishment of an Urban Renewal Commission, finalising the Perth Public Transport Plan, establishing an Independent State Infrastructure Body, and providing incentives for developers that meet requirements around sustainability, design quality and provision of affordable and diverse housing.