Western Australia is trying to cut urban sprawl. Infill housing is the answer

The Kings Park gardens, Perth. Image: Getty.

With state governments across Australia acknowledging the need to limit urban sprawl, fill the gaps within existing metropolitan areas and build higher-density housing on selected sites, many opportunities have opened up. Demonstration projects are key to ensuring quality outcomes – and government has a leading role to play.

The Western Australian target for urban infill is at the lower end compared to other states. In August 2010, the Department of Planning and the Western Australian Planning Commission released Directions 2031 and Beyond, a report that proposed a more consolidated Perth, with an infill target of 47 per cent of new housing.

In 2015, the same two government agencies released the draft document, Perth and Peel@3.5 million, which again nominated the 47 per cent infill target. However, the authors acknowledged that urban infill rates had reached only 28 per cent in 2014. This means that, to reach the 47 per cent goal, the required increase in infill has moved from 50 per cent to 68 per cent more than the actual infill numbers in the five years between the two reports.

Filling the housing gap

This is a substantial change, and one that will require significant shifts from “business-as-usual” approaches to housing delivery along with community acceptance of higher residential densities. Government can assist with these shifts and, in doing so, help to fill a conspicuous gap in the content of the reports.

This gap is the absence of anything more than the briefest of references to the nature of the housing that will provide the increased infill and density. There is no real discussion of housing types and design, methods of construction and delivery, or forms of ownership that may encourage a greater take-up of such housing.

Higher residential density and infill continue to face a level of community resistance. Some of this is justified, in that much of the completed suburban infill is of a poor quality and too fragmented to deliver the positive changes and level of amenity that higher density can bring.

A quick Google Maps scan across the middle suburbs of Perth shows the dominant form of suburban infill in the city. It is a compressed suburbia. Large houses are squeezed together onto sites, shrinking usable private outdoor space to leftover space, reducing access to sun and cross-ventilation, and diminishing existing tree canopy. Driveways, car courts and double garage doors engage with the street.

Standard industry infill strategies in middle-ring or greyfield suburbs. Image: Faculty of Art, Design & Architecture, Monash University/author provided.

How do we improve infill?

Looking at this prompts the question: how do we improve the standard? Researchers at Swinburne and Monash universities in Melbourne and at the Australian Urban Design Research Centre (AUDRC) at the University of Western Australia have proposed solutions.

The Monash project, Infill Opportunities: Design Research Report, prepared for the Office of the Victorian Government Architect, explores how considered design strategies can contribute to better-quality infill redevelopment in the middle-ring suburbs. The strategies include:

  • going above a single storey, with the height shifted away from site boundaries to reduce overlooking and shadow-casting of neighbours;

  • allocating usable private courtyards to each unit;

  • providing good solar access, cross-ventilation and outlook; and

  • developing a car-parking strategy that can change over time.

In addition, the idea is for the units to have a degree of inbuilt flexibility so they can adapt to changing household circumstances. While this work remains diagrammatic, it nevertheless demonstrates that, with a clear focus on how design can enable amenity to be optimised, suburban infill can provide attractive housing options.

There are infill projects being built in Perth that demonstrate what is possible when real design intelligence is at play. For example, LandCorp’s stage 1 development of Knutsford, 1.5km from the centre of Fremantle, provides a mix of well-considered housing types. These feature good indoor-outdoor relationships and clever spatial strategies to enable a high degree of internal flexibility.

This housing is being offered to the market at very reasonable prices. In stage 1, 23 units were completed, with 33 being built in stage 2, all designed by Spaceagency.

The streetscape of stage 1 at Knutsford, designed by Spaceagency, is free of driveways, with access at the rear. Image: Robert Frith/author provided.

We need more good examples like this, with a greater diversity of housing types. The potential that is implicit in higher-density housing – the opportunities for social engagement, sharing of facilities, fewer cars, richer urban potential, better public space and urban realm – needs to be made explicit.

Time to revisit the display village

For more than 50 years, display villages have been used to promote and sell detached project housing. These displays have enabled buyers to see what they are buying and to understand the potential of the broader setting of the house.

The quality of design helped stage 1 of Knutsford to sell within months. Image: Robert Frith/author provided.

Historically, display villages promoted, through built example, the houses that eventually formed suburbia. In the same way, a display village for higher-density housing units could promote options that are not currently on offer in the housing market.

Potential buyers would be able to experience and understand the qualities of the housing on display. A higher-density display village would demonstrate how, with intelligent design, these units can be spacious, adaptable and work effectively with outdoor space.

For Perth, such a display village would provide a valuable means for industry to innovate with housing types and forms of construction. A government imprimatur and the willingness to underwrite the first projects should ensure this outcome.

The village would offer design diversity in terms of type and form, construction innovation including modular and prefabrication techniques, use of new materials, and the ability to test new strategies for utilities and waste.

It would showcase design for low energy use on a precinct scale and for reduced car dependency. It would take advantage of Perth’s climate and allow a fluid relationship between indoors and outdoors, creating a sense of space, light and air.


Infill can add value to suburbs

Government and industry would plan and promote the project. Government would provide the land and industry would build the housing. The display housing would be open to the public for a period of time, then sold to individual buyers.

Affordability remains a major obstacle to broader acceptance of higher-density housing. This is because selling prices per square metre are considerably more than those of a detached new house on the suburban fringes. The display village could explore alternative forms of land and house delivery and ownership.

Higher-density housing isn’t necessarily a threat to the traditional Australian notion of suburbia. It need not be seen as a denigration of the values that recognise suburbia as having a particular quality that helps establish the idea of an Australian way of life based on the detached house and its backyard. There is a vast existing stock to ensure those values will remain in place.

The development of well-designed, high-performing and higher-density infill housing will, in fact, protect existing suburbs from the poorer-quality infill that is occurring, while allowing the benefits of an enhanced public realm to be shared.

The WA government has a major challenge in meeting its infill targets. It can help meet this challenge by initiating a government-assisted display village of quality higher-density housing. It would be the first state government in Australia to do so.The Conversation

Geoffrey London is professor of architecture at the University of Western Australia.

This article was originally published on The Conversation. Read the original article.

 
 
 
 

How bad is the air pollution on the average subway network?

The New York Subway. Image: Getty.

Four more major Indian cities will soon have their own metro lines, the country’s government has announced. On the other side of the Himalayas, Shanghai is building its 14th subway line, set to open in 2020, adding 38.5 km and 32 stations to the world’s largest subway network. And New Yorkers can finally enjoy their Second Avenue Subway line after waiting for almost 100 years for it to arrive.

In Europe alone, commuters in more than 60 cities use rail subways. Internationally, more than 120m people commute by them every day. We count around 4.8m riders per day in London, 5.3m in Paris, 6.8m in Tokyo, 9.7m in Moscow and 10m in Beijing.

Subways are vital for commuting in crowded cities, something that will become more and more important over time – according to a United Nations 2014 report, half of the world’s population is now urban. They can also play a part in reducing outdoor air pollution in large metropolises by helping to reduce motor-vehicle use.

Large amounts of breathable particles (particulate matter, or PM) and nitrogen dioxide (NO2), produced in part by industrial emissions and road traffic, are responsible for shortening the lifespans of city dwellers. Public transportation systems such as subways have thus seemed like a solution to reduce air pollution in the urban environment.

But what is the air like that we breathe underground, on the rail platforms and inside trains?

Mixed air quality

Over the last decade, several pioneering studies have monitored subway air quality across a range of cities in Europe, Asia and the Americas. The database is incomplete, but is growing and is already valuable.

Subway, Tokyo, 2016. Image: Mildiou/Flickr/creative commons.

For example, comparing air quality on subway, bus, tram and walking journeys from the same origin to the same destination in Barcelona, revealed that subway air had higher levels of air pollution than in trams or walking in the street, but slightly lower than those in buses. Similar lower values for subway environments compared to other public transport modes have been demonstrated by studies in Hong Kong, Mexico City, Istanbul and Santiago de Chile.

Of wheels and brakes

Such differences have been attributed to different wheel materials and braking mechanisms, as well as to variations in ventilation and air conditioning systems, but may also relate to differences in measurement campaign protocols and choice of sampling sites.

Second Avenue Subway in the making, New York, 2013. Image: MTA Capital Construction/Rehema Trimiew/Wikimedia Commons.

Key factors influencing subway air pollution will include station depth, date of construction, type of ventilation (natural/air conditioning), types of brakes (electromagnetic or conventional brake pads) and wheels (rubber or steel) used on the trains, train frequency and more recently the presence or absence of platform screen-door systems.

In particular, much subway particulate matter is sourced from moving train parts such as wheels and brake pads, as well as from the steel rails and power-supply materials, making the particles dominantly iron-containing.


To date, there is no clear epidemiological indication of abnormal health effects on underground workers and commuters. New York subway workers have been exposed to such air without significant observed impacts on their health, and no increased risk of lung cancer was found among subway train drivers in the Stockholm subway system.

But a note of caution is struck by the observations of scholars who found that employees working on the platforms of Stockholm underground, where PM concentrations were greatest, tended to have higher levels of risk markers for cardiovascular disease than ticket sellers and train drivers.

The dominantly ferrous particles are mixed with particles from a range of other sources, including rock ballast from the track, biological aerosols (such as bacteria and viruses), and air from the outdoors, and driven through the tunnel system on turbulent air currents generated by the trains themselves and ventilation systems.

Comparing platforms

The most extensive measurement programme on subway platforms to date has been carried out in the Barcelona subway system, where 30 stations with differing designs were studied under the frame of IMPROVE LIFE project with additional support from the AXA Research Fund.

It reveals substantial variations in particle-matter concentrations. The stations with just a single tunnel with one rail track separated from the platform by glass barrier systems showed on average half the concentration of such particles in comparison with conventional stations, which have no barrier between the platform and tracks. The use of air-conditioning has been shown to produce lower particle-matter concentrations inside carriages.

In trains where it is possible to open the windows, such as in Athens, concentrations can be shown generally to increase inside the train when passing through tunnels and more specifically when the train enters the tunnel at high speed.

According to their construction material, you may breath different kind of particles on various platforms worldwide. Image: London Tube/Wikimedia Commons.

Monitoring stations

Although there are no existing legal controls on air quality in the subway environment, research should be moving towards realistic methods of mitigating particle pollution. Our experience in the Barcelona subway system, with its considerable range of different station designs and operating ventilation systems, is that each platform has its own specific atmospheric micro environment.

To design solutions, one will need to take into account local conditions of each station. Only then can researchers assess the influences of pollution generated from moving train parts.

The ConversationSuch research is still growing and will increase as subway operating companies are now more aware about how cleaner air leads directly to better health for city commuters.

Fulvio Amato is a tenured scientist at the Spanish National Research CouncilTeresa Moreno is a tenured scientist at the Institute of Environmental Assessment and Water Research (IDAEA), Spanish Scientific Research Council CSIC.

This article was originally published on The Conversation. Read the original article.