What factors influence our decision to stay or move?

Swiss homes – just like our cars, TVs and waistlines – have gotten considerably larger over the past four decades. Average floor area per capita increased from 34 m² in 1980 to 46 m² in 2019, and this figure looks set to keep growing.

What’s behind this growing appetite for space? How can we reverse this trend in order to make housing more environmentally sustainable? And, most important of all, how can we shrink the size of our homes without compromising on our standard of living? Claudine Karlen, Anna Pagani and Claudia Binder, from EPFL’s Laboratory on Human-Environment Relations in Urban Systems (HERUS), tackle these questions in a paper published in the Journal of Housing and the Built Environment. Their research touches on some thorny housing-related issues that have never been studied in this depth before.

Taking a more sustainable approach to this segment of the country’s housing market could make a huge difference over the coming decade

National Research Programme
Housing is the second-largest contributor to Swiss energy consumption and CO₂ emissions, just behind transportation. And if the current pace of growth continues, there’ll be no option but to keep building new homes on greenfield sites outside city centers. In 2017, the Swiss government launched a National Research Programme on resource efficiency, including in the housing industry. Professor Philippe Thalmann at EPFL’s Laboratory of Environmental and Urban Economics (LEURE) is currently supervising a PhD research into the factors that shape homeowners’ decisions to renovate, demolish or build new housing. Another PhD student at ETH Zurich is studying the environmental footprint of housing, looking in particular at construction materials and energy use. The HERUS scientists chose to focus on tenants knowing that their research could be a game-changer. “Some 60% of Swiss people rent their homes,” says Pagani, an architect and PhD student. “Taking a more sustainable approach to this segment of the country’s housing market could make a huge difference over the coming decade.”

Questionnaire and interviews
In the fall of 2019, the scientists sent out a questionnaire and organised group discussions with people renting from two cooperatives – Société Coopérative d’Habitation Lausanne (SCHL) and Allgemeine Baugenossenschaft Zürich (ABZ) – and from insurance company Swiss Mobiliar, representing a combined total of 10,000 dwellings. The survey received 968 responses. The tenants were asked what prompted them to move into their current home and what might trigger them to move again in the future.

Key housing functions
Around 40% of respondents moved to a larger dwelling even though their household size had decreased. When asked about a possible future move, just 25% of respondents indicated that they would be willing to downsize if their household shrunk. In 46% of cases, respondents said they wouldn’t be willing to move because they were attached to their current dwelling, while 30% said they already found their current home too small. Other reasons included good location and cheap rent (both 7%) and attachment to their current neighborhood and community. “We summarized these preferences into nine functions,” explains Pagani. “We found that several of them act as obstacles to reducing housing size: for instance, status symbol, which is our home as a reflection of our social status; permanence, which is our attachment to our current dwelling and neighborhood; privacy, which increases as our homes have more space per household member.”

Several possible answers
Persuading a retired couple to move out of a large city-center apartment is not an easy task. Nor is discouraging a neighbor from moving somewhere bigger just because they want a bit more space. The scientists suggest several possible answers, including introducing financial incentives to encourage people to move, ensuring an adequate supply of small city-center dwellings with good public-transportation links, and having apartments of different sizes in the same building so people can move without losing touch with friends and neighbors. They also recommend giving downsizers priority over other potential tenants.

“We should rethink our approach to privacy at the building-wide scale, such as by providing workshops and music rooms that tenants can rent

Workshops and music rooms to rent
Pagani advocates “rethinking our approach to privacy at the building-wide scale, such as by providing workshops and music rooms that tenants can rent.” She also calls for greater flexibility in the layout of buildings as a way to adapt to the evolution of the household and satisfy the need for permanence. And on the subject of the home as a status symbol, she points to the key role that the media, architects and designers can play in “creating a new ‘sustainable’ status symbol, for instance by championing smaller dwellings that offer a high standard of living.”

Computer model
The main output of Pagani’s PhD research is a new computer model, into which she incorporated the study’s findings. Cooperative owners and landlords can use the model to assess the impact of measures to reduce the environmental footprint of housing, while taking tenants’ preferences into account.