Fire regulations for bio-based construction: the sector in shock

Dated July 20, 2021, a document summarizes in 20 pages the “doctrine” of the Paris Police Prefecture in terms of protecting biosourced buildings against fire.

Caption: Fire test which allowed straw construction to approach the sector of Establishments open to the public

On July 17, the 10th International Wood Construction Forum ended in Paris, which had set itself the ambition of bringing the message of biosourced construction to the capital as a necessary development in the face of climate change.

In the aisles of the Forum, some delegates released their anger at the way in which the representatives of the Paris fire brigade questioned both the fire tests and the quality of the constructions, carried out by the Adivbois organization.

The Adivbois Fire Workshop was created five years ago to facilitate the development of fire regulations adapted to the new framework of mid-rise biosourced buildings that this organization is supposed to promote.

It brings together some of the greatest specialists in fire protection, and it has also opened its doors to firefighters, who, for convenience, are the Paris firefighters, directly attached, via the Prefecture of the Paris Police, at the Ministry of the Interior.

Is the trauma of the Notre-Dame cathedral fire involved in the writing of the doctrine by the Paris firefighters? ©JT

Work carried out by Adivbois to develop regulations

For five years, the workshop has been progressing painfully. However, some stakeholders, who experienced a similar situation during the 1970s with the introduction of regulations on high-rise steel construction, believe that in comparison, the rate of progress of work towards development of appropriate regulations is very fast.

But now the RE2020 arrives and recommends, in the face of global warming, the massive development of biosourced construction, therefore also that of medium height. As the start-up date for RE2020 has been set for early 2022, the government convened an inter-ministerial commission in February 2021 to bring together the points of view of the Ministry of the Environment, the Interior, housing and others.

In this way, the technical debate has also become a political debate between different government ministers. At the same time, the Atelier Incendie AdivBois continued to sit under the direction of François Consigny, always with the presence of representatives of the Paris fire brigade.

Inflamed speech for wood construction by the Minister of Agriculture on the occasion of the 10th International Wood Construction Forum, four days before the publication of the doctrine of the firefighters of the Paris Police Prefecture. ©JT

A 20-page brochure summarizes the fire safety doctrine

The Forum Bois de Paris was greeted by the Minister of Agriculture, Mr. Denormandie and by the Minister of Housing, Mrs. Wargon. The Minister of Agriculture communicated his faith in the development of bio-based construction.

The conference program, drawn up for the most part at the end of 2019, could not take into account the progress of the interministerial commission initiated at the beginning of 2021, and, in agreement with AdivBois, chose to reflect other centers of interest of this organization. promotion of wood.

Three days after the end of the Parisian demonstration, and eight days before the publication of the decree relating to the RE2020, the direction of Transport and the protection of the public of the Prefecture of Police of Paris, (and more precisely the sub- direction of public safety with the Paris fire brigade, the central laboratory of the Prefecture of Police and the service of security architects), have published a brochure of some twenty pages setting out their point of view on fire safety in biosourced buildings, which most construction players only become aware of when they return to school with a certain bewilderment.

The doctrine of firefighters establishes a general point of view

The document is not set up as a regulation but establishes a general point of view, a doctrine, which must prevail in the instruction of the files that the firefighters deal with. Everyone knows the power of firefighters who can, in France, suspend the delivery of a Building at the very last moment.

In addition, the firefighters of Paris constitute a kind of national reference, the Parisian doctrine is quickly applied elsewhere than in Paris and in the Petite Couronne, in practice. And as the firefighters depend on the Ministry of the Interior, therefore on the heart of the State, everyone is circumspect.

Exposed or enclosed wooden walls?

On the technical level, the current debate is complicated and moreover, the doctrine of the firefighters aims to simplify things. Simplifying them further, one of the stumbling blocks of the current situation is the possibility or not of building in height with interior or exterior walls visible in wood.

Biosourced tertiary construction willingly exploits these warm flat areas of structural materials such as CLT or BLC (glued laminated wood). Even in medium-rise housing such as Sensations in Strasbourg, or, initially, the Cartoucherie in Toulouse, this option was chosen.

Alas, in April 2018, a facade igniting test carried out by Efectis and partly financed by the owners of the Sensations building then under construction, made it clear that the exposed wooden walls could contribute to reviving a fire even after its root cause has been extinguished.

Douglas clothing enclosing the straw for the Bertelotte residence in Paris 15th. A precursor building? ©JT

Exposed wooden surfaces covered with plasterboard

Following the Efectis trial, and in a context strongly marked by the Grenfell tragedy in London, certain projects in progress, such as the Cartoucherie, were revised in order to cover the exposed wooden surfaces with plasterboard.

At the same time, a European study has been undertaken to establish to what extent these visible wooden surfaces can be preserved without compromising the safety of the building. In a short time, Great Britain launched a battery of tests which are not standardized, but which seem to be decisive in understanding the situation.

France intended to start similar trials this year, but supply problems pushed the start date to the end of September 2021.

A tense end to the year for biobased with the entry into force of RE2020

So that we find ourselves at the end of 2021 with the imminence of the entry into force of the RE2020 supposed to promote the biosourced approach, the expectation of the analysis of European and French tests and a doctrine of the Paris police headquarters, which one wonders if this is not simply a maximalist position in the context of negotiations by the interministerial commission.

It would seem that the sector does not intend to develop a counter-doctrine, but it stands united, from one meeting of the interministerial commission to the next. We also hear about letters, even legal proceedings with the administrative court.

In short, the response does not yet seem to be specified and moreover, we do not even know who are the supporters of this doctrine of firefighters, apart from the Prefecture of Police. Is the Ministry of the Interior really involved? The position of the mayor of Paris is apparently not clarified.

Hide this wood that I cannot see! Auditorium designed by Marie Schweitzer with Lifteam in Paris: according to the doctrine of firefighters, the regulatory distinction between the uses of buildings would become null and void.© JT

A complicated comeback for the wood industry

The actors of this soap opera are in shock because the publication of the doctrine of the firefighters occurred without consultation with the other members of the Fire Workshop of AdivBois. The market for timber construction studies is highly disrupted.

"The design offices are forced to develop solutions according to two possibilities, the possibility of the doctrine and that of the current regulations, which leads us to do the work twice", explains a wood design office.

Clients such as Paris Habitat, which has just inaugurated the Bertelotte residence (Paris 15th) with wooden walls insulated with straw, are struggling to share the praise and political extrapolations from all sides in relation to this complex, biosourced achievement. and using straw, which now becomes even more difficult to reproduce.

A "at the same time" that does not pass

The publication of the firefighters' doctrine undermines the government's ecological strategy at a time when ecology risks becoming the number one subject of the electoral campaign, given the catastrophic conclusions of the latest IPCC report.

So far, the summer skirmish has only been seen by insiders. But its range is such that the noise of the bullets will not be long in whistling on the political ground.

Source: batirama.com/Jonas Tophoven