Working site of the National Archives, in Belval, Luxembourg.
The “state of crisis” of the construction sector in Luxembourg
It feels like there always is an open working site wherever you go in Luxembourg. This has to do with the population and economic growth over the last ten years, and the considerable speculation in the sector (to learn more, read our article On Land Use: the housing crisis in Luxembourg). Yet, the global construction industry, including Luxembourg, is grappling with material shortages due to supply chain disruptions that are primarily due to some factors.
Vincent Hein, Director of the Idea Foundation (the economic policy think tank), confirms that it is the construction sector that lost the most jobs in Luxembourg in 2023. However, according to STATEC (the Institut National de la Statistique et des Études Économiques in Luxembourg), it is the logistics sector that experienced the biggest drop in activity (7.7%). There follow the financial and insurance activities (-7%) and the construction (-7.4%).
Following the Covid-19 pandemic, lockdowns and restrictions on movement disrupted manufacturing and transportation, creating obstruction and delays. As economies rebounded post-pandemic, the demand for building materials surged, outpacing production capacity. Furthermore, the Russian invasion of Ukraine has disrupted the flow of key materials like steel, timber, and certain minerals from Eastern Europe and Russia. Finally, a lack of workers in the manufacturing, the transportation and the logistics sector in Luxembourg further congested the movement of materials.
The price hikes that affect material availability, play a role in impacting the budgets of building projects. Additionally, contractors might struggle to find specific materials, missing deadlines. Incidentally, companies need to explore alternative materials.
Among the impacted materials, we can find: steel, timber, concrete, electronics and appliances. The construction sector is required to focus on sourcing materials from local or regional suppliers to reduce dependence on strained global supply chains. Thus, exploring alternative materials can help keep projects progressing.
Notably, Luxembourg's government declared the “state of crisis” of the construction industry for a period of six months from 1 February 2024. In particular, companies will be able to benefit from a simplified procedure for obtaining partial unemployment working in residential and non-residential construction, as well as in demolition and site preparation. Civil engineering is not included for the moment. Labour Minister Georges Mischo stresses that: “The [construction] sector is essential to the Luxembourg labour market. The companies in the sector will need these employees as soon as the economy recovers.”
Reflection of the Restaurant de l'Université, in Belval, Luxembourg.
Use fewer natural resources by reclaiming old building components
Being between 25 and 30% of the total waste volume created in the European Union, construction and demolition waste (CDW) represents the most significant type of waste. All in all, the built environment sector is responsible for 37% of global emissions.
The construction sector is Luxembourg's second largest source of CO2 emissions. Even though GHG emissions in Luxembourg are declining, carbon emissions in the building sector and in agriculture have continued to rise. Additionally, the building industry is the biggest source of waste in the country, with landfilling capacities for rubble generated in construction and demolition works under collapse.
Around 50% of inert waste is currently recycled in most EU countries, with the majority of CDW being destined for backfilling and downcycling. Following demolitions, building materials are generally recycled by crushing or melting, or disposed of. The result is a high environmental impact and a net loss of economic value.
In North-West Europe, reuse and upcycling of CDW remains below 3% — this means that only a very small part of technically reusable elements are reclaimed and repurposed in another building.
Clearly, actions must be taken for Luxembourg to meet the year-in-year 1.6 t CO2 eq per capita by 2050. After the European Directive 2008/98/EC on waste, Luxembourg promulgated the national law on waste on March 12th, 2012, where reuse was barely mentioned. Article 26 of the law foresaw the creation of an inventory to identify and list the different materials used in a structure prior to demolition. Only in 2018, the Environmental Administration and LIST (Luxembourg Institute of Science and Technology) clarified the practical aspects of such an inventory. This was done after 2018 Plan National de Gestion des Déchets et des Ressources (PNGDR) and the governmental Null Offall Lëtzebuerg (“Zero Waste Luxembourg”) strategy.
In the same way, the European Parliament's Circular Economy Package does set targets for reuse and recycling efforts of inert waste by 2024. We understand that a measure must be put in place to contain the imports of building materials.
Luxembourg's shortage of construction materials
CIRCTER (Circular Economy and Territorial Consequences, a spin-off of the Ministry of Energy and Spatial Planning according to the EU’s ESPON programme) informs us that the construction industry is heavily dependent on imports. Similarly, a great volume of metal ores is registered in connection to the activity of Arcelor Mittal, after the dismantling of the mining sector in the Grand Duchy.
The Domestic Material Consumption (DMC) per capita of Luxembourg is more than double of the other regions (excluding Stockholm), while its extraction is among the lowest. In particular, the use of construction materials is more than double that in other regions. Luxembourg’s DMC is invariably dominated by construction materials (as per non-metallic minerals), which makes up more than half of the total.
The steady economic expansion of Luxembourg, along with the growth of domestic population, have translated into an ever growing demand for building materials — especially sand and gravel — increasingly covered by imports. The entire amount of sand and gravel is destined for construction activities in the country. Between the biggest streams, we can also find liquid and gaseous energy material/carriers.
Import shares of non-metallic materials in thousand tonnes, 2018, Luxembourg, by EUROSTAT.
Sheila Aggarwal-Khan, Director of UNEP’s Industry and Economy Division, claims that: “Net zero in the building and construction sector is achievable by 2050, as long as governments put in place the right policy, incentives and regulation to bring a shift in the industry.”
The UNEP (UN Environment Programme) suggests three strategies to decarbonise building materials: avoid unnecessary extraction and production by adopting a circular approach; shift to regenerative materials (including timber, bamboo, and biomass); improve decarbonisation of conventional components (namely concrete, steel, and aluminium, glass, bricks). The accent is on reuse and recycle, with the ultimate purpose of prolonging the life of construction materials.
Circular construction: making up for the limited supply of construction materials in Luxembourg
We learn from Bruno Domange, Senior Environmental Engineer at LIST, that it is fundamental to distinguish between the demolition and the deconstruction process, where selective disassembly is to be preferred. Buildings are still too often demolished, while the new approach calls for old buildings to be considered as stocks of raw materials at the end of their life.
Compiling an inventory of elements and materials with an intention to reuse is essential with regard to sustainable resource management and a circular economy for materials. Policy-makers are required to adopt a different approach, by applying Life Cycle Analysis (LCA) methods. The impact of using, for the same requirement, reused building materials can be 2 to 12 lower than new equivalents.
Life Cycle Approach applied to the building industry, by Luxembourg's Ministry of the Environment, Climate and Sustainable Development, 2020.
LIST was invited to participate in the Interreg FCRBE project (Facilitating the Circulation of Reclaimed Building Elements in Northwestern Europe), together with France, Belgium and the UK, and help disseminate knowledge about reuse practices. Through a comprehensive deconstruction guide based on thirty case studies, the professionals in the sector — from contractors, carpenters and roofers, to infrastructure workers and demolition contractors — can learn about the best practices and how a construction site should operate according to ambitious yet realistic reuse objectives.
LIST is also a partner of the Digital Deconstruction (DDC) transnational network — one of the innovative Interreg North West Europe (NWE) initiatives — that wishes to optimise deconstruction and reuse efforts through an open-source software. The solution functions as a decision support system and aims to make up for the poor digitalisation of the construction sector. The system integrates various digital tools (3D scanning, Building Information Modelling, a digital materials & buildings database, blockchain technology), that were tested on occasion of ten pilot projects.
A materials inventory for deconstructions in Luxembourg
The waste management law was last modified on 9 June 2022, making it compulsory for buildings of 1,200 m³ or more to have a materials inventory for deconstruction, and for an electronic inventory to be made available. For new buildings, this inventory will include the location of materials, for all building permits granted from 1 January 2025. The syndicate or building manager is also required to update the inventory if the building is modified.
The materials inventory aims to promote the re-use of materials that have not yet lost their function. For new projects, the materials inventory will be in the form of a BIM model. This requirement will give a major boost to the digitisation of construction.
The forward-looking Samuel Majerus, Partner and Director of the QSE2 department at Simon-Christiansen & Associés, amnticipates in 2018: “I think that one of the next major steps in sustainable construction will be the creation of a materials passport. We already have an embodied energy performance certificate for buildings. I am convinced that, in time, the equivalent for materials — an environmental performance certificate — will enable us to measure and regulate the environmental footprint of buildings.” The mentioned environmental footprint of buildings is to be measured throughout the entire lifespan of a building, from the time of building to deconstruction.
Linear vs cyclic model in the building industry, as per Elma Durmisevic, 2006.
Where to buy or take reclaimed materials and products
Reclaiming construction materials entails a whole set of actions: from auditing, performance testing, dismantling, sorting, cleaning, dimensioning, stockholding, and documenting; to advertising, selling, shipping, and pre-financing some operations. Timely interventions ensure the effective reuse of the materials, where technical studies are instrumental in assessing their energy efficiency performance and their actual aptness to the new intended use. The inventory takes into consideration not only the quality but also the quantity of a specific element. Historical or aesthetic value should also be taken in account.
Experts in charge of conducting waste audits are usually not very familiar with the reuse and the reclamation process; thus the assistance of an architect, a reclamation dealer or a demolition contractor can be key in this context.
Decisions for reclamation are primarily taken from an economical perspective, where products that have proved to be economically viable in the past have more opportunities to be reused. The total cost of reclamation and preparation of the element are estimated and compared to the cost of a similar new product on the market.
Remarkably, the value of the components to be re-used lies both in their intrinsic qualities (nature, composition, dimensions) and in their perfect condition after dismantling (absence of damage, general condition, presence of all constituent parts). To this end, Luxembourg’s Ministry of Environment declares that it is important to have a good command of techniques for dismantling and packaging components too.
We learn from the Interreg FCRBE that there generally are three channels for reclaimed products: online marketplaces; donations; producers (e.g. a factory who will create other products starting from the reclaimed material). Online marketplaces can be either addressed to private consumers and/or businesses. Secondly, elements which present a good reuse potential but lack economic value (due to low quantity, for instance) are generally donated. Donations are increasingly becoming more frequent between large contractors who ‘swap’ materials that they are able to employ in new projects they are involved in. Finally, the third channel sees producers taking back large amounts of their own products. Recycling building materials is more common than reuse in this specific context.
The platform Opalis supplies materials in Luxembourg, Belgium, the Netherlands, France. Yet, in Luxembourg there seems to be only a registered vendor, as compared to the other countries (Belgium, 119; the Netherlands, 167; France, 253). Furthermore, the Re:USE (by BIM-Y) is a completely Luxembourg-based marketplace, powered by 3D scanning to create material inventories.
Interestingly, Marc Neu’s Naturbaustoff, in Redange, is the first shop in Luxembourg to be fully dedicated to the growing market in eco-friendly and natural new construction materials.
Several companies in both the waste management and the construction sector offer their expertise in reclaimed construction materials. Additionally, training courses are made available by the major lifelong learning organisations. Conversely, some architecture firms are a little more shy when it comes to approaching the subject. They are aware of the environmental impact of their interventions but show no practical experience in the field.
A working site with a wooden pallet against a red building, in Belval, Luxembourg.
Four architecture projects in Luxembourg that incorporate recycled building materials
We can count four major projects in Luxembourg, where construction components were reused. They are Ettelbrück train station, and Äederschëff, in Redange. While the other two are located in Luxembourg City: the Lycée Michel Lucius, in Limpertsberg, the European Parliament’s Jean Monnet Building, in Kirchberg.
Contacted by LIST, Schröeder & Associés chose Ettelbrück station as a pilot project for the Digital Deconstruction initiative. By testing the BIM-Y 3D scanner to create materials passports, they were able to reclaim 17% of construction elements in 2022. They identified the same materials as the Jean Monnet Building’s as well as cut stones. Red sandstone and traditional shale are materials of great interest to be recovered during deconstructions to restore lintels, as they can no longer be found in Luxembourg.
Prior to that, they collaborated with CFL (Société Nationale des Chemins de Fer Luxembourgeois) for the dismantling of buildings in Luxembourg and Mersch. They also helped the municipality of Bertrange to disassembly a school.
Schröeder & Associés — the specialists in deconstruction in the Grad Duchy — were also behind the deconstruction of the European Parliament’s Jean Monnet Building (2018-19), in Kirchberg. On the occasion, they selectively reused concrete (recycled/crushed), aluminium, and glass panels, while finding problematic elements such as asbestos.
During the summer of 2022, the architecture firm participated free of charge in La Petite Maison, a joint project with the University of Luxembourg, architect Carole Schmit and LIST. Installed on the Belval university campus, the ephemeral structure put the circularity of resources at the heart of the European Cultural Capital, Esch 2022.
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A working site with a wooden pallet and a orange and blue cable, in Belval, Luxembourg.
Secondly, the case of the Lycée Michel Lucius sees two old buildings being adapted between 2018 and 2021, to accommodate a new function. Two wings (the 3000 wing, from 1973; the 6000 wing, from 1997) were respectively converted into a library with a connected reading room, and an esplanade. These were two highly prefabricated buildings — one with a metal frame, while the other in wood.
The 3000 wing, from 1973, was largely demolished. During the dismantling of the building, part of the original steel frame was salvaged to build a canopy next to the esplanade and to renovate the 6000 wing.
With regard to the 6000 wing, most of the original building was kept in place. This conversion required the majority of the partition walls to be removed. Ten classrooms (out of the original twenty-four) were retained for extracurricular activities.
The chosen solution was by far the quickest and the most economically convenient, reducing the production of demolition waste by 79% and saving 458 to 792 tonnes of CO2 equivalent. It was equally possible to increase the proportion of recycled aggregates used in the composition of the concrete to 60%.
Äederschëff, in Redange-sur-Attert, has a very distinct story, as it does not feature a deconstruction but a structure that was built from scratch, where we can find reused materials. Built on around 1,000m² of public land from the Atert-Lycée Redange, Äederschëff is an adaptation of Mike Reynolds’ principles of Earthship Biotecture to Luxembourg's climatic conditions and to the standards of European environmental legislation.
The structure is home to the CELL (Centre for Ecological Learning Luxembourg), which plans to develop and host visits for schools and the youth as well as workshops on sustainable living and low tech, with the support of the Ministry of the Environment, Climate and Sustainable Development and the Ministry of Education.
Thanks to European and national funding, the construction phase (2019-2022) followed the design (2014-2017). The project came from a few citizens who had organised as a steering group and built partnerships with local companies and experts.
The building is intended to be 100% self-sufficient in terms of the production and management of its water, sanitation, heating, electricity (thanks to solar panels) and food sovereignty (making use of an aquaponics system). It includes a large training room, an office and a room used as private quarters for two volunteers.
Worn tires filled with rammed soil provided the structure of the pillars and the large rear wall. Rob Hirsch — expert educated at Reynolds’ Earthship Academy in Taos, New Mexico, and consultant for the Äerdschëff initiative — explains that: “This thermal mass makes it possible to absorb heat from the interior space when it is hot, and to diffuse the heat stored when it is cold.”
While, the south large window wall — where we can find a greenhouse now — was created with recovered windows that were installed by a company this time. Additionally, an adobe wall, between the great hall and the kitchen, reclaimed the clay from the site. And, a natural cellar was dug directly into the ground to maintain a constant cool temperature, avoiding the use of a fridge to preserve food.
The Äerdschëff also used glass bottles as bricks, old doors, shredded hemp fibres for the roof, wood, straw and limestone for the flooring. The initiative also involved the implementation of autochthonous miscanthus grass for insulation purposes.
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Working site from the National Archives with a blue and a white cabin, in Belval, Luxembourg.
New construction builds: sustainability across the entire life cycle of the construction materials
The whole approach to the construction sector must change, by thinking long-term about a new building. When choosing the materials to be employed in a new building, we have to take into consideration their potential for future reuse and recycling as well as the cost of their whole lifecycle, from the moment of design, the construction, to the maintenance, the renovation and eventually the the time of disassembly. This must be done in the full interest of lengthening the lifespan of material elements. For this specific reason, we should choose durable, healthy and high-quality materials. In the same way, old buildings are to be considered as repositories of reusable materials.
Reusing building products definitely is an effective way to increase the demand for products with a lower environmental impact, notably in terms of CO2 production, and to limit the depletion of non-renewable resources. In so doing, we can prevent unnecessary waste generation, avoid end-of-life treatments and keep valuable resources in circulation, while reducing the demand for new products. The advancements in the law in Luxembourg definitely are very promising.
Inversely, we can reduce construction costs and at the same time, cut waste management costs and potentially earn a profit from the sale of the materials. Nonetheless, the margin associated with these materials can also be very small, as there is no reduced VAT rate or exemption. Furthermore, there generally is a tough price competition between reused and new materials.
It is therefore ideal to use few natural, mostly regionally produced materials that are fully reusable and recyclable. Yet, the layout of existing buildings and the pressing demand for real estate make it attractive to replace the materials, in favour of bigger and shinier constructions. In fact, speculation still represents a major threat.
Martine Schummer, head of the Buildings department at Schrõeder & Associés, comments: “To manage waste optimally, the best solution is to create modular buildings, adaptable according to changing needs. It is possible to increase its flexibility by reducing the number of vertical load-bearing elements, or to increase the free heights of the floors to allow changes in use. […] This approach generally generates higher construction costs than a traditional construction, but it increases the value of the building in the long term.”
Similarly, Schummer states that the identification of the elements that can be reused at the time of the materials inventory, reduces the cost of a project by 15 to 20%. It definitely is necessary to integrate these methods into the design and the construction practices.