What are the challenges of sustainably developing the suburbs?

© O. Wavre / LAST / 2016 EPFL

© O. Wavre / LAST / 2016 EPFL

EPFL researchers have identified a number of factors that play a key role in the sustainable development of outer urban areas. They used West Lausanne as a case study, and they have just published their findings in a new book.

The book SuburbanPolarity presents the results of a series of teaching and research initiatives by EPFL’s Laboratory of Architecture and Sustainable Technologies (LAST), which is headed by Emmanuel Rey. These initiatives include nine projects carried out by students who participated in the Suburban Landscape (2014–2015) and Suburban Polarity (2015–2016) workshops. Nearly 75 architecture students were involved in some way, from the overall urban project all the way down to construction details. Working with a team of teachers and other experts, their goal was to analyze, explore and experiment with the difficulties inherent in creating new and sustainable suburban polarities. They used the fast-growing West Lausanne region as their case study. Interview with Emmanuel Rey.

Based on your findings, in what ways does West Lausanne hold strategic growth potential? Why was it chosen as the case study?

Despite the many negative associations with urban sprawl, a consensus has gradually emerged around the need to promote strategies aimed at densifying already urbanized areas. This issue goes beyond the city center alone to include large suburban outskirts, such as West Lausanne in the Lausanne-Morges conurbation. In these heterogeneous areas, which are not fully urban or rural, sites with existing or future public transport nearby are of particular strategic interest. They offer potential new polarities that are at once dense, mixed and interlinked by sustainable transport. The students whose initiatives are discussed in Suburban Polarity focused on a site that enabled them to explore the many challenges raised by this type of suburban transformation taking place close to public transport. The site in question is located in Crissier. It covers an area of around 25 hectares and comprises various types of spaces – including an old industrial site left over from the Renens brick, tile and pottery works. It also has a strategic advantage in that it is very close to a stop on a public bus line that will run between Bussigny and Lutry, passing through Place St-François in the center of Lausanne. This line, which is slated to enter service sometime between 2025 and 2030, will rely on buses with a high level of service (BHLS).

What sort of development ideas does the book propose?

The different approaches set out in the book reflect divergent opinions regarding the size the buildings should have, ranging from a large number of fragmentary structures or staggered blocks of buildings to one open block or new takes on the utopian megastructures that were the fashion in the 1960s and 1970s. The visions developed also reveal different attitudes towards the site’s slope. While some prefer a terraced approach, which would mean grading the structures, others highlight a contrast between horizontally oriented buildings and the site's natural incline. The student projects tend to follow one of three stances, which line up with three different architectural attitudes towards creating a suburban polarity. The visions are grouped accordingly in the book: those organized around a central point, those that define the outer contours of the new neighborhood and those that are based on creating a dense network of unbuilt space. The book also presents a comparative evaluation of the nine visions using a multi-criteria methodology called NEBIUS (Neighborhood-scale Evaluation to Benchmark the Integration of Urban Sustainability), which was developed by the Laboratory of Architecture and Sustainable Technologies.

What sorts of errors must architects avoid when it comes to this type of urban development?

When creating suburban polarity, the emphasis must be on developing high quality spaces in terms of both the buildings and the landscaping. In addition, special attention must be paid to the project’s compatibility with the site, its connections with neighboring sectors – especially through green transport – and the creation of new public and semi-public spaces. And to avoid the bedroom community feel, these new neighborhoods should offer a mix of functions and activities. For the conurbation as a whole, it is important to avoid the temptation of trying to compete with the real center of town and, in terms of sustainability, not to encourage the extensive use of individual motorized transport. That said, making room for some specialized services and local merchants in the neighborhood and accommodating some services and craftsmen can help achieve the right balance. It’s also worth mentioning the high level of demand in suburban areas for spaces devoted to small and medium-sized manufacturing and craft firms that do not create any sort of nuisances in the neighborhood.

The book also looks at the architect’s role in this type of urban development. Based on your findings, what place will architects have, what challenges will they face, and what sort of freedom will they enjoy in the coming years?

Given the trend of urban densification, and with the recent changes to Swiss legislation regarding land-use planning, architects will be called on to reconcile density and quality of life in the built environment. For new urban development projects, architects will have to translate the interests of various sectors into coherent spatial visions. At the same time, they will face a multitude of qualitative challenges, involving urban morphology, the relationship between built and landscaped spaces, the continuity of public spaces, the creation of inventive forms of housing, energy efficiency, and managing the requirements of high environmental quality. These sites, because they are neither city centers nor rural suburbs, present a number of very specific challenges for architectural design, which must address the contrast between highly heterogeneous landscapes and rethink the relationship between urban, farming and undeveloped land. These polarities will require a strong architectural identity if they are to help structure the landscape of the greater urban area and come up with new features associated with a high standard of living. In view of these many challenges, architectural design will require innovative and exploratory solutions – combining invention, hybridization and transposition – in order to make the most of local resources and incorporate concepts that are now considered essential, such as sustainable resource management, quality of use and urban intensity.


Reference

Suburban Polarity, Emmanuel Rey (ed.), preface by André de Herde, with contributions from Marilyne Andersen, Pierre Feddersen, Frédéric Frank, Vincent Kaufmann, Sophie Lufkin, Giuseppe Peronato, Parag Rastogi, Emmanuel Rey and Arnaud Thuillard, Presses Polytechniques et Universitaires Romandes, December 2017.