CSTB Research Day: More than 700 stakeholders gathered for the 2026 edition, dedicated to the renovation of the building stock

All the presentations, discussions, and roundtables are available today in replay.

Park renovation: major and complex challenges

More than a need, the renovation of the housing stock is a priority, in response to multiple societal and environmental challenges: adaptation to climate change, comfort, health, decarbonization, resource conservation, access to housing for all, living well together...

These complex issues are the focus of much expectation and call for a profound transformation of works, practices, and frameworks of thought. Research plays an important role in this transformation.

Renovating and transforming: the contributions of research

Launching the Research Day, Julien Hans, Director of Research and Innovation at CSTB, reminded everyone that to achieve the essential massification of renovation, "solutions exist and are being developed, the knowledge is there, and there is no shortage of innovations."

However, the pace needs to be accelerated. In this regard, he specifies, research is a key tool: "applied, persistent research, fundamentally rooted in the field and connected to all stakeholders."

This dynamic is already underway. The event on June 2nd provided an opportunity to share progress, also exploring levers to accelerate the park's transition.

Several major themes for the sector were thus highlighted:

• Park-wide data, knowledge and renovation strategies
• Adaptation to climate change and summer comfort
• Indoor environmental quality and health
• Resources, materials and construction innovations (bio-based, geo-based...)
• Actual building performance and guaranteed results
• Occupant safety: fire, structural and natural risks
• Transformations of sectors, skills and economic models

Presentations and roundtables punctuated the day. For example:

• Informing park-wide renovation strategies
• Measuring the actual performance of buildings
• Making renovation more reliable and enhancing quality
• Decision support and multi-criteria approach in renovation
• The contribution of bio-based materials
• Existing building stock: structural risks and fire safety
• Supporting innovation for renovation
• Structural changes in the renovation market to sustainably address the challenges of performance and evolution of the existing building stock

Beyond Research: A Necessary Collective Dynamic

To conclude this day of discussions and expertise, Etienne Crépon, President of the CSTB, whose term is coming to an end, stressed the importance of collective and multidisciplinary action to effectively address the challenges and priorities of renovating and transforming the building stock:

"What will make the difference is not an isolated innovation, but the progressive convergence of multiple contributions. And in this convergence, everyone has a place. A useful place. A necessary place. It is this ability to act together, assuming everyone's share, that will allow us to meet the challenges before us."

Watch the replay of Research Day 2026