Driving Sustainable Construction Forward: What the New Saint-Gobain Action Paper Means for Leca
The construction sector is at the heart of today’s biggest challenges: climate change, resource scarcity, urbanisation and social well-being. To stay within planetary boundaries while continuing to build and renew our cities, the way we design, build and renovate must change – fast.
As part of the Saint-Gobain Group, Leca International fully supports this transition. That’s why we’re pleased to highlight the 2025 Action Paper from Saint-Gobain’s Sustainable Construction Observatory, a new publication that sets out a practical roadmap to accelerate sustainable construction worldwide.
In this article, we summarise the key messages of the Action Paper and reflect on how Leca® lightweight aggregate (Leca® LWA) and our solutions can help turn these ideas into reality.
A collective roadmap for sustainable construction
The Sustainable Construction Observatory was launched in 2023 to bring together stakeholders across the construction value chain: industry, public authorities, finance, NGOs, academia and citizens. Its mission is simple but ambitious: accelerate the transformation toward sustainable construction at global scale.
The 2025 Action Paper is the result of:
An initial analysis by the Observatory team
Contributions from 12 international experts in buildings, cities and climate
A large digital consultation with over 200 participants in 36 countries
A high-level workshop during Climate Week NYC 2025 where 35 leaders co-designed priority actions
Out of this collaborative process, six “transformative issues” and 13 priority actions were identified. Together, they form a concrete roadmap to scale sustainable construction and drive systemic change.
Six transformative issues shaping tomorrow’s built environment
The Action Paper doesn’t try to cover everything. Instead, it focuses on six levers that can unlock major impact across the sector:
1. Build a common, comprehensive definition of sustainable construction
The concept of “sustainable construction” is now widely used – in policies, strategies and project briefs. Yet the Observatory’s 2025 Barometer shows that, although 67% of stakeholders say they’re familiar with the term, there is still no clear, shared understanding of what it includes.
Without a common language, it’s difficult to compare projects, set targets or align incentives. The Action Paper calls for a holistic definition that balances:
Environmental performance
Social and health outcomes
Economic value and long-term viability
2. Strengthen collaboration across the value chain
Construction is inherently collaborative – but today, the value chain remains fragmented. From material producers and designers to contractors, investors, regulators and users, too many decisions are still made in silos.
The Paper underlines the need for new forms of partnership and governance, where stakeholders:
Share data and knowledge
Co-develop solutions and standards
Align on common objectives for climate, resilience and social impact
3. Integrate adaptation and resilience, not just mitigation
The transition has long focused on energy efficiency and carbon reduction. While essential, these are only part of the answer. In a world of more frequent heatwaves, floods and extreme weather, buildings and infrastructure must also withstand shocks, protect people and adapt over time.
Resilience and adaptation need to be embedded in:
Design criteria and planning
Choice of materials and systems
Regulations, finance and insurance frameworks
4. Address the specific needs of emerging economies
By 2050, cities are expected to host 2.5 billion additional people, mostly in emerging economies. Countries like India and Nigeria will see particularly rapid urban growth.
The Action Paper highlights that these regions face strong constraints (cost, access to finance, regulatory capacity) but also huge potential: decisions taken today will lock in building performance for decades. Structured, context-specific approaches are needed to:
Support affordable, low-carbon housing and infrastructure
Leverage local materials and skills
Build resilience to climate risks from day one
5. Demonstrate the economic profitability of sustainable construction
Globally, more than one in three stakeholders believes that making sustainable products and solutions more competitive is the single most important action to speed up the transition.
Sustainable construction is still often seen as:
More complex
More expensive
Harder to scale
The Paper calls for better demonstration of the full economic value – reduced operational costs, longer service life, lower maintenance, better health and productivity, and improved resilience.
6. Shift perceptions: from compliance to desirability
Finally, sustainable construction is too often perceived as a constraint – a regulatory burden or technical challenge. To accelerate adoption, we need to change the story:
From “something we must do”
To “something that improves lives, comfort and safety”
This means communicating more about tangible benefits for people, communities and cities – not only about emissions or regulations.
How Leca contributes to this transformation
As a Saint-Gobain company and a long-standing supplier of expanded clay lightweight aggregate, Leca International is directly engaged in many of the themes highlighted in the Action Paper.
Here are some of the ways Leca® solutions support this roadmap:
A material aligned with a holistic view of sustainability
Leca® LWA is a durable, reusable, and versatile lightweight aggregate that improves the environmental, social and economic performance of buildings and infrastructure throughout their life cycle.
Environmental: lower bulk density can reduce material use and transport loads; good thermal performance supports energy efficiency; long service life reduces replacement needs.
Social: better comfort, noise and moisture management contribute to healthier, more resilient living environments.
Economic: lighter structures, faster installation and long durability can lower total cost over the asset’s lifetime.
This fits well with the Action Paper’s call for integrated definitions and metrics that go beyond a purely operational energy lens.
Enabling resilient and adaptive designs
Resilience is one of the central issues of the Action Paper – and it’s an area where expanded clay brings clear advantages. Leca® solutions are used in applications such as:
Geotechnical works where low weight reduces settlement and improves stability
Flood protection, drainage and stormwater management, helping manage intense rainfall and protect critical infrastructure
Thermal and frost insulation in foundations and infrastructure, supporting performance in changing climate conditions
These applications show how materials can contribute not only to mitigation, but also to adaptation and risk reduction.
Supporting emerging markets with practical, scalable solutions
Because Leca® LWA is simple, robust and easy to handle, it can be a valuable solution in fast-growing markets where there is pressure to build quickly while improving quality and resilience.
Its versatility – from housing to infrastructure and water management – allows local stakeholders to use a single, well-known material across many applications, simplifying logistics and training.
Demonstrating long-term value
The misconception that sustainable construction always costs more is a major barrier identified in the Action Paper. Leca projects across Europe consistently show that:
Reducing weight can cut structural requirements and foundation costs
Fast installation and simple handling lower labour time on site
Long-lasting performance reduces maintenance and replacement needs
By documenting and sharing these outcomes, Leca helps demonstrate the economic case for sustainable, resilient solutions.
Making sustainable construction desirable
Finally, the Paper calls for a narrative shift: sustainable construction should be seen as an opportunity to build better places to live and work. Through our case studies, BUILD magazine and local projects, we aim to show how Leca® solutions contribute to:
More comfortable homes
Safer and more reliable infrastructure
Smarter, nature-based water management
In other words: resilient, efficient and attractive environments that people are proud to inhabit.
What’s next?
The 2025 Action Paper from Saint-Gobain’s Sustainable Construction Observatory is both a call to action and a toolbox for all actors in the built environment. It offers:
A shared framework for talking about sustainable construction
Six priority issues that can unlock systemic change
13 concrete actions to guide strategies and projects worldwide
At Leca International, we are committed to playing our part – by innovating in our products and processes, partnering across the value chain, and proving every day that sustainable construction is not only possible, but desirable and profitable.
👉 You can learn more and download the full Action Paper HERE
If you’d like to explore how Leca® solutions can support your next sustainable construction project – from housing and infrastructure to water management – our teams across Europe are ready to help.
