Who Really Renovates? Survey Reveals Stark Divide in Europe’s Home Energy Upgrades

Europe’s climate ambitions rest heavily on the assumption that millions of homeowners will renovate their properties, insulate their walls, and swap oil boilers for heat pumps over the coming decades. Yet a new study of more than 1,600 households straddling the Swiss-French border reveals that renovation activity is anything but evenly spread. Instead, it clusters in predictable pockets of the population, leaving some of the worst-performing homes largely untouched. The research, published in the Journal of Industrial Ecology, offers one of the most detailed portraits yet of how real households, rather than idealised building typologies, actually reshape the places they live in.

The study, led by Ankita Singhvi of the École Polytechnique Fédérale de Lausanne together with colleagues at Delft University of Technology, draws on survey data collected between June and December 2023 from owner-occupiers in the Lémanic region, a cross-border area spanning western Switzerland and eastern France around Lake Geneva. Of 11,154 people invited to participate, 5,534 responded, a remarkably high response rate of 49.6 percent. After filtering for owner-occupiers who completed all relevant questions, the final dataset comprised 1,603 households. Respondents reported renovations carried out over the preceding fifteen years, covering thermal envelope work such as façade, roof and basement insulation and window replacement, as well as heating system upgrades, air-conditioning installations and photovoltaic panels.

What sets the study apart is its analytical framing. Rather than segmenting the building stock by construction period or building type, as most building stock models do, the researchers used a clustering algorithm called Partitioning Around Medoids, applied to a Gower distance matrix suitable for mixed numerical and categorical data. This allowed them to group households by the intersection of who lives in a dwelling and what that dwelling is like. The analysis identified six distinct household-dwelling groups, ranging from single-person households in ageing urban apartments with oil heating to affluent families in newly constructed, heat-pump-heated apartments rated A or B for energy performance.

The headline finding is stark: annualised energy-efficient renovation rates, defined as at least two qualifying interventions such as envelope improvements, heating upgrades or solar installations within a time period, ranged from 0.4 to 2.8 percent of the dwelling stock per year across the six groups. The sample average of 1.9 percent per year sits close to Swiss and European policy targets of 2 to 3 percent, but that average conceals enormous variation. Intervention rates for individual building components differed by up to a factor of seven between groups. Couples in large detached suburban houses and settled families in rural and suburban detached homes, both high-income groups, renovated at nearly double the sample average, while single-person households in older apartments and elderly long-term residents of mid-sized dwellings lagged far behind, despite living in some of the least efficient buildings.

The drivers behind these decisions tell an equally revealing story. Households that renovated rarely did so for abstract climate reasons. Instead, roughly 38 percent of the two most active groups cited high energy costs they had directly experienced, while others pointed to component defects, pending maintenance, or preparations before moving in. Subsidies and tax incentives motivated 27 percent of elderly long-term residents, and expert recommendations mattered most for single-person households and elderly couples. The researchers interpret these patterns through the theory of planned behaviour, which holds that action depends not only on intention but on perceived ability to act, and their data suggest that experienced discomfort and cost, rather than anticipated energy savings, are what push owners to pick up the drill.

Perhaps the most policy-relevant discovery concerns households who see no problem to solve. Among those living in dwellings rated A to C for energy performance, 75 percent considered their home’s energy performance adequate and saw no reason to renovate. More strikingly, 42 percent of occupants of D- or E-rated dwellings, homes that are formally energy inefficient, also perceived their performance as sufficient. In these cases, the authors argue, financial incentives alone are unlikely to shift behaviour, because the households perceive no problem worth solving. This gap between thermal comfort as experienced by residents and decarbonisation as demanded by climate targets represents a blind spot for subsidy-based renovation policy.

Organisational barriers emerged as another decisive constraint. Among single-person households in mid-sized apartments, 40 percent cited the difficulty of collective decision-making with neighbours as a barrier to renovation, a challenge inherent to owner-occupied multi-family buildings where façade insulation or central heating replacement requires coordination across multiple units. The authors suggest that where low renovation activity stems from coordination problems rather than individual disinterest, household-targeted financial support will fall short, and dedicated renovation coaches who can guide the social organisation of multi-family buildings may be more effective.

The study also captures a technology transition unfolding in real time. Photovoltaic installations showed the most dramatic acceleration of any intervention: the sample-average rate of 1.7 percent per year over fifteen years masks a surge to 6.9 percent in the most recent year alone. Families in newly constructed apartments installed solar panels at 3.1 percent per year, nearly double the average, and across all groups, intentions to install PV exceed intentions for envelope or heating upgrades. Air-conditioning followed a similar upward trajectory, particularly among suburban couples and new-build residents, despite regulatory disincentives in both countries. The authors caution that this enthusiasm is misaligned with climate priorities: replacing fossil-fuel heating delivers far greater emission reductions than adding solar panels, and PV adoption has been linked to a ‘solar rebound’ in which households become less conscious of their electricity use and consume more. Rising cooling demand, meanwhile, is growing faster than any other energy service in buildings.

Projecting stated intentions forward, the researchers estimate that by 2035, 55 percent of the surveyed dwelling stock will have undergone at least one thermal envelope renovation since 2008, 41 percent a heating system replacement, 52 percent a PV installation, and 13 percent an air-conditioning installation. But the lowest cumulative activity is projected precisely for the groups whose buildings need it most: single-person households in older apartments, elderly long-term residents, and, for different reasons, families whose new homes already perform well. The authors are careful to note that intentions do not always translate into action, a well-documented intention-behaviour gap in sustainability research, and a follow-up panel survey conducted in 2025 will allow them to compare stated plans against actual renovations.

For policymakers, the message is that renovation support cannot be one-size-fits-all. Because intentions are unevenly distributed across the stock, the authors argue there is a clear opportunity to target monitoring and assistance at household-dwelling groups with both low energy performance and low renovation intentions, tailoring instruments to whether the binding constraint is money, coordination, information, or simply the perception that nothing needs fixing. For modellers, the study demonstrates that segmenting buildings by construction period alone misses much of the behavioural heterogeneity that determines whether Europe’s renovation targets are met. The building stock, the research suggests, does not evolve according to the service lives of components but according to the lives, budgets and beliefs of the people inside them, and climate policy will only succeed when it engages with that human dimension.

Subject of Research: Actor-driven energy renovation dynamics in the French and Swiss owner-occupied residential building stock

Article Title: From the household up: renovation dynamics in the French and Swiss owner-occupied residential building stock

Article References: Singhvi, A., Sirenko, M., Athanassiadis, A., & Binder, C. R. (2026). From the household up: renovation dynamics in the French and Swiss owner-occupied residential building stock. Journal of Industrial Ecology, 30(4), 2101-2117. https://doi.org/10.1007/s44498-026-00142-9

Image Credits: AI Generated

DOI: 10.1007/s44498-026-00142-9

Keywords: building stock, energy-efficient renovation, owner-occupiers, household survey, thermal envelope, photovoltaics, heat pumps, cluster analysis, industrial ecology, energy policy, Switzerland, France