The regulatory framework for bio-based materials has just taken a major step forward. In a decision dated February 23, 2026, the Council of State confirmed the legality of the decree governing the "bio-based building" label, putting an end to a dispute initiated by manufacturers in the traditional insulation sector.
Beyond a simple legal debate, this decision secures the criteria for awarding the label and clarifies the place of bio-based insulation materials in projects with high environmental ambitions. For manufacturers, distributors, and insulation companies, the implications are strategic, commercial, and regulatory.
Concrete analysis of the issues and consequences of this decree for professionals in the insulation market.
1. Background: why was this decree contested?
The "bio-based building" label, provided for in the Building and Housing Code (Article D. 171-6), aims to promote buildings that incorporate a significant amount of materials that store biogenic carbon.
The decree of July 2, 2024 sets out the conditions for awarding the label and defines several levels (1, 2, and 3).
To achieve levels 2 and 3, the text requires that the bio-based products used fulfill several distinct technical functions, including, mandatorily, thermal insulation.
The National Union of Manufacturers of Manufactured Mineral Wool Insulation (SN-FILMM) challenged this decree. In particular, it considered that:
- the text indirectly favored bio-based insulation materials;
- the functional requirement was legally questionable;
- the principle of equality between products could be called into question.
2. The official decision of the Council of State
The Council of State rejected all of the arguments put forward by the union that brought the case.
He ruled that:
- the regulatory authority was competent to set specific technical criteria for a voluntary label;
- The requirement to use bio-based products that provide thermal insulation in order to achieve higher levels of the label is legal.
- no breach of the principle of equality has been identified;
- no obvious error of judgment was made by the ministers.
In short: the decree is validated in its entirety.
This is a final decision under French administrative law, as the Council of State is the highest court in the administrative system.
3. What this means for insulation professionals
3.1. The label remains voluntary
First key point: the "bio-based building" label is not a general regulatory requirement.
No legislation requires all buildings to use bio-based insulation. It is a voluntary measure.
However, in practice, a label can become a strategic criterion in calls for tenders, public procurement, or projects with high environmental ambitions.
3.2. Legal certainty for criteria favoring bio-based insulation materials
For manufacturers and companies specializing in bio-based insulation, the decision is transformative.
The Council of State confirms that:
- Higher levels of the label may require bio-based materials to fulfill the function of thermal insulation.
- This requirement is legally sound.
This means that project owners wishing to obtain levels 2 or 3 will have to incorporate bio-based insulation solutions into their design strategy.
For insulation companies, this may include:
- a commercial lever;
- a differentiating factor during the bidding phase;
- a key factor in specifications for design offices and architects.
3.3. Competition regulated but not excluded
The decision does not create a ban on non-bio-based insulation materials.
It simply validates the fact that a public environmental label can promote certain categories of products in line with its objectives (carbon storage, environmental impact, circularity).
In other words, the regulatory framework now clearly accepts that environmental criteria guide the design of certified buildings.
3.4. Regulatory stability in the short and medium term
By rejecting the appeal and confirming that there was no manifest error of assessment, the Council of State has conferred a high degree of legal stability on the current system.
Unless there are future regulatory changes by the government, the label criteria are now consolidated.
For professionals, this allows:
- to invest more confidently in the development of bio-based product ranges;
- adapt sales pitches;
- to develop a strategy around environmental labels.
4. Key points for industry players to watch out for
Even if the decision is favorable to bio-based products, several factors must be taken into account:
- the label remains voluntary: its impact will depend on demand from project owners;
- The specific technical criteria must be strictly adhered to (documentation, traceability, compliance with functional requirements).
- Future regulatory changes remain possible, depending on political developments.
It is therefore strategic for professionals to:
- monitor annual regulatory changes to the label;
- enhance the technical and regulatory robustness of their products;
- integrate these requirements into their marketing and sales tools.
The decision of the Council of State on February 23, 2026 legally validates the decree governing the "bio-based building" label and confirms the legality of the requirements relating to thermal insulation for upper floors.
For insulation professionals, particularly manufacturers and installers of bio-based insulation such as cellulose insulation, this is a strong signal:
- the regulatory framework authorizes and secures the use of bio-based insulation materials in buildings with high environmental ambitions;
- the criteria are now stabilized;
- The label can become a strategic lever in markets with high carbon requirements.
Against a backdrop of increasingly stringent low-carbon policies, this decision reinforces the legal and commercial legitimacy of bio-based insulation solutions.
