"Off-site construction, a major asset in the service of decarbonization" (Pascal Chazal)

4039 France - Last modified by the author on 10/02/2023 - 11:51

Pascal Chazal, director of Hors-site magazine and president of Campus Hors-site, the first school specializing in off-site construction, is also CEO of Patch Conseil, an off-site construction consulting firm. It highlights the advantages of this construction system, already well established abroad, which is tending to develop in France.

Aluminum, concrete, wood etc. what are the most suitable materials for off-site construction?

Off-site construction is not about materials but about process! It is possible to work off-site with all the materials, however the materials of the dry sector are often preferred, because the drying time and the weight of the concrete are obstacles to industrialization.

Between 2D and 3D what is the current trend? The benefits of each method?

2D is for the moment widely preferred because it does not change habits too much, construction actors for years have been integrating 2D concrete elements into their projects, more recently wooden elements, facades for example. 3D offers a very strong potential for improvement and is developing all over the world at exponential speed, but to succeed, habits must be changed, for factories to be able to produce efficiently, the design must be adapted, that purchasing processes are changing, it's a real paradigm shift.

Does RE2020 promote off-site construction? Does it make a real difference in the calculation of carbon emissions?

Yes, RE2020 will push very hard towards off-site construction, the need to reduce the carbon impact will push players to use less concrete and turn to recyclable, renewable and biosourced materials. Steel and wood will therefore be used more and more, these materials are not transformed on site but in workshops or factories, it's off-site. Moreover, as certain studies (Cambridge, Edinburgh, Lulea, etc.) prove. Off-site construction significantly reduces the carbon impact of construction, it reduces waste, transport makes better use of hours and materials, up to 40% reduction in on-board carbon!

To what extent can off-site be used in the context of renovations (excluding EnergieSprong)?

The volume of high-performance renovations is so considerable (700,000 housing units per year) that the workforce will never be sufficient if everything is done on site. Studies (Greenflex, Energiesprong) have shown that a third of housing can be renovated using prefabrication. Producing elements in the factory speeds up the renovation process and frees up workers for more complex operations where prefabrication is not a good solution.

Are there prefabrications that rely on low carbon, and in particular bio-sourced materials?

Yes, of course, many players are looking to create local loops and to use biosourced materials, hemp, earth, flax, straw, and even stone. It is easier to incorporate them in a workshop and deliver a finished element to the site.

Is France ahead of its European neighbours? Internationally ?

France has made a lot of progress in recent years on wood, it is catching up on Scandinavia, Germany or Austria, but the vision is a building vision: we design as usual, as if we were going to build the concrete building, once designed, we look for a pre-manufacturer, there is no search for optimization, it works we know how to do it but the cost is too high. France, on the other hand, is lagging behind other countries in terms of industrialization, modular construction, constructionOff-site and new construction methods. The United Kingdom is far ahead, with a very strong commitment from the government, which has understood that to set up a real industry, it must be given visibility on its order book. They do this by setting up multi-billion pound framework agreements.

Can you give us some French examples? And internationally?

In France, we see a good development of certain wood companies, Mathis for example or like the Master cube network, other actors make industrialization an asset like GA Smart Building. Internationally, there are many examples, such as Boklok (IKEA) in Sweden, Goldbeck in Germany, Laing O'rourque or Tide construction in the United Kingdom. We have an article in the last issue of Off-site on Tide and Vision Modular which is a real success story.

What are the major innovations expected for 2023?

The expected innovations are more cultural than technical, for the off-site to develop, it is above all necessary that the upstream actors, elected officials, politicians, project owners, designers understand the Off-site construction is a major asset in the service of decarbonization that the benefits are great for the country on the environmental, social and economic levels. The speech of Emmanuel Macron, of the Minister of Housing Olivier Klein in favor of off-site construction are strong signs.

How do you judge the development prospects for the sector?

All the major firms agree that off-site construction will develop very quickly and very strongly, that it could represent 30% of the market by 2030. We have led with Batimat, ACIM and Campus Off-site a survey for the second time as part of the Off-site construction barometer, we interviewed more than 400 decision-makers, contracting authorities and contractors, 80% of whom believe that Off-site construction -site will grow in the coming years. It is however not a long calm river, faced with the difficulties of building on site, the new standards, (RE2020) demand is coming in droves, manufacturers are investing, but they are struggling to be profitable, the market is not oriented towards the factories but towards the site, that is what it is imperative to change otherwise the factories will close for lack of profitability.

Comments collected by Stéphanie Obadia, Editorial Director
and Grégoire Brethomé, Editorial Manager - Construction21

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Grégoire Brethomé - Construction21

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