Building sustainably through innovation

Innovation in the construction sector is needed to bring down its inevitably big effect on carbon emissions. While front runners are tripping over red tape, authorities are devising all-inclusive regulation as researchers advocate working together.

Source : journal.lu
Publication date : 09/27/2023

 

Notoriously, human impact is the main reason for climate change, kick-started by the industrial revolution some 250 years ago. Today, we are trying to adapt by ushering in the age of sustainability. But a few pesky sectors are struggling to get off the mark. Globally, the construction industry marked record high carbon emissions in 2021, according to a report by the United Nations Environment Programme (UNEP). In Luxembourg, the government has targeted improvement in this domain, however a 2022 assessment outlined that a lot more effort is still needed. 

Innovation is the most obvious solution for a construction sector that is finding it hard to take a step in a different direction. In this category, there are many positive examples in Luxembourg, including front-runners such as Stugalux. Each of the construction company’s employees has a Building Information Modelling (BIM) app on their phone, which displays a digital representation of all projects. This tool allows construction companies to catalogue extensive information on quantities of materials, to view a 3D model of the building, and to better collaborate internally. Having data on how much wood, concrete, steel, and other such components are used in a project is essential when it comes to sustainability. Having this data can allow companies to reuse in the future materials from demolished buildings that would otherwise be overlooked or not utilised adequately. Salvaging parts of buildings is not a new concept as the owner of Stugalux, Joel Schons points out: "Most of the marble from the Colosseum, in Rome, you can find it in the buildings in Vatican City." Therefore, sustainability is not about reinventing the wheel, but about using better tools to reduce our carbon footprint.

Different conditions require different materials

Adaptation is also needed in heating. The temperatures that Luxembourg experiences have changed significantly since the construction of most buildings that are now in place. Long, freezing winters are a thing of the past and insulation materials have evolved a lot. "Our insulation is so good that basically cooking spaghetti in the morning in the evening and the afternoon or doing some kind of heating with your system [generates] enough heat within your house, and it stays within your house, " says Schons. Electric appliances such as refrigerators radiate heat and can contribute to warming up a room. So, the challenge that architects and construction companies in Luxembourg are more and more facing now is how to keep the heat out rather than in. Air conditioning is not a preferred solution due to its intensive use of electricity, the production of which leads to more carbon emissions. Using materials like, hemp, straw or recycled cotton as insulation can be a sustainable option when it comes to protecting a building from the temperatures outside.

What stands out, however, is the use of paint as insulation. Embedded with microscopic hollow ceramic and glass spheres, that resist thermal conduction, this product is looking for its place in the toolbox of architects and painters. It is relatively untested, but Schons insists that his company is serious about giving it a go. "Stugalux has everybody inside the company from machinery, roofing, electricity, HVAC, up to painting to do a single-family home completely by ourselves. Basically, what we have is a caterpillar that is eating land and pooping housing, " he says. This makes it easier to try out materials that are new on the market and explore in what ways construction can be more sustainable. Vacuum insulation panels, made of reusable and 100 per cent recyclable materials, are another innovative tool which Stugalux had its eyes on. Nevertheless, the company was not allowed to use them when they tried to do so because at the time regulations specified a range of thickness for the panels and, surprisingly, they were too thin.

Regulation headaches

While insulation doesn’t get the whole job done, techniques such as indirect shadow can be used to counter exposure to the sun in key parts of a building. One way to optimise the use of land and materials is an AI space design software. An architect can use this tool to calculate the best way to fit, for example, a residential building with a set number of flats in a selected plot of land. Other variables can include solar panels, positioning of the house regarding sunlight or the size of the windows. It goes so far as to even do internal adjustments of the rooms. Being able to simulate construction to such a detail in the early stages of a project can help avoid mistakes and can have an effect on energy consumption in the building. "AI allows you to find solutions, far quicker in all domains, even in material science. It's far quicker than we knew it before", says Luc Biever director of innovation at Stugalux. "This means that if today you find something, it doesn't mean that tomorrow you can use it." In reality, all the projects, for which Stugalux used the AI software, were refused by the corresponding municipality.

Regulations within communes tend to be exceedingly specific and vary from one another. For example, flat roofs are not accepted in some districts. While in Kirchberg one can build a 20-story building, in rural areas only single-family homes can be made. "We have 100 communes. So, we have 100 different rules. The complexity regarding what you are able to build and where is really high. If you have a land, which is in two different municipalities, it could be that in one place, you can do this and on the other side, they don't want it, " says Biever. While not allowing excessively tall buildings in rural areas is understandable, flexibility in other domains can make possible the application of more sustainable methods.

Imposing wholesale changes on all municipalities is something the state cannot do due to a clear separation of competencies. But it is with them that Stugalux appears to run into problems regularly. An issue that stands out, notably for Schons, is the large gap between being allocated a plot of land and being able to start building. He cites one of the company’s latest housing projects in Dudelange which took 30 years to begin. The most excessive example is a 64-year gap between the mayor of Echternach announcing that the city will expand and Stugalux being able to get construction under way. "It’s far too long, " agrees Paul Schosseler, director of sustainable construction and circular economy at the Ministry of Energy. Although this issue stems from each commune’s set of rules, it does exist throughout the country. "Municipalities can decide a lot of things, and it’s good because there are some really innovative and proactive ones. So, there aren't only blockages, " retorts Schosseler. Communes can also push innovative initiatives relatively fast compared to state legislation which has many layers and lengthy procedures. The Ministry of Energy’s circular economy director also outlines that regulation can drive innovation forward if done correctly, but doing that has its challenges. "Joel Schons is very innovative with BIM, and he can show you his buildings on his mobile phone and that’s great. They are front-runners, and they improve much faster, and they should. But we have to make sure that we [push legislation that benefits] the whole sector because it will apply to the whole sector, " says Schosseler.

Pining for bio-sourced materials

On a governmental level, the Ministries of Energy, Environment and Economy joined their efforts in the creation of a Circular Economy Strategy, published in 2021. It covers the multiple sectors, with construction identified as one with a major importance for the domestic economy. For this first iteration, the ministries focused on creating a governmental framework and did not solicit companies. They relied on the Economy Ministry’s expertise, since it is in contact with economic actors as part of its work.

An important element targeted by the Circular Economy Strategy is materials, wood standing out in particular. That is not only due to its rise in popularity, but also because the production capacity of biological materials is limited by the available land. Schosseler describes the current state of Luxembourg’s forests as being "under stress" with lack of precipitation and shifts in temperatures being the main cause. In other words: climate change. One way to promote better management of this faltering resource is cascaded use, which the ministries have included in their strategy. This term refers to the practice of bio-sourced materials being processed into a product and then utilised at least once more for either material or energy purposes. Luxinnovation’s wood cluster is another example of the efforts made in this regard. The state-backed agency’s platform fosters the exchange of wood between players in the sector, acting as a bridge between producers and consumers.

Still, there is one big question mark over Luxembourg’s timber, and that is its quality. "Really good hardwood needs different seasons, " says Biever. With winters not being what they used to be, the quality of the product also suffers. For that reason, many construction companies opt for sourcing wood from far away, Russia being a popular option before the war in Ukraine. This, of course, significantly increases the carbon footprint of the construction process.

For Biever, some nice Luxembourgish oak wood can be "good to make a cask and age some wine in it" but it does not possess the resistance needed to make an entire roof from it. Schosseler, however, says that wood sourced in the grand duchy can be used in construction, and he identifies it as an important part of the ministry’s decarbonisation strategy. For him, an example of this is the construction of a nursery in Roodt-Syre with the use of beech from municipal forests, processed by the sawmill Bois Scholtes in Manternach. At the same time, the ministry’s sustainability director insists that there is a limit on how much can be used due to the condition of local forests. "Pine trees are very useful for construction because they are very straight, and they make great beams, " says Schosseler. "But the problem is they are all dying, because they are simply not adapted to the changing climate conditions." Change is also needed in the fields, which is illustrated by a pilot project overseen by the Ministry of Energy. It aims to support the growing of hemp which doesn’t need to be sprayed because there aren’t any pests endangering the plant here, explains Schosseler. Luxembourg’s Drinking Water Law, updated in 2023, does not allow the use of pesticides and herbicides in a number of precisely identified zones. Planting hemp instead has been identified as a solution by the ministry. Other than its more eye-catching yield, CBD oil, the plant is valued in construction for its fibre. It is used as insulation, especially in refurbishment works which are an important part of efforts to reduce energy costs, be it for climate or financial reasons. This installation needs to be replaced more often than traditional ones, but it is more sustainable than its counterpart styropor which is derived from petroleum.

Choosing the right materials will help Luxembourg’s carbon footprint in the short to medium term, but what will ultimately be decisive is data and using that information properly. Knowing the quantity of each component used in a building is key, and a material passport with this exact purpose is set to become mandatory in January 2025. Meanwhile, the Energy Ministry presented in June 2023 a roadmap to decarbonisation of the construction sector. Its goal is to determine the entirety of emissions produced during a building cycle, including materials manufactured abroad. The effects of transport, including that of excavated soil, will also be under the microscope. As it is explained in the roadmap, between 4 and 7 years will be needed for the roadmap’s entire plan to come to fruition and based on that, tools will be identified to decarbonise the construction industry. This time, architects, engineers, and entrepreneurs from the sector will be closely involved in the process.

Optimising logistics

The inclusion of transport in the ministry’s calculation is a welcome one because it is an aspect of putting up buildings that is largely overlooked. However, it’s uncertain how successful that will be. "This method can allow for very precise and detailed calculation of impacts. But what happens in practice is that it is often calculated in a very simplistic way or even neglected, " says Fabrice Berroir, R&D Engineer at Luxembourg’s Institute of Science and Technology (LIST). Being unaware of this data or missing parts of the bigger picture can have a significant impact. Berroir points to construction logistics accounting for "20 and 35 per cent of urban freight, 10 to 20 per cent of construction costs and more than 50 per cent of work-related accidents". It is also a significant contributor to air pollution. Due to the ingrained overlooking of details part of the execution phase of building, some legislators and experts think they aren’t that big. There is a vicious circle, however, in which not having a lot of data leads to believing the impact is not significant and thinking this leads to not exploring that data, explains Berroir. Optimising logistics can, however, play an innovative role just like materials do, but on a bigger scale.

Berroir sees LIST’s projects as proof of concept and a way to incentivise legislation. "The decision makers are more often followers than drivers. They want to see results first, and we have the opportunity to show things that work, " says the researcher. An example of this is LIST’s partnership with manufacturer CLE and logistics operator Polygone in an effort to enable better management of materials towards and from construction sites.

"Traditionally, one material is delivered to a construction site and then moved on average 8 times after its delivery, " says Berroir. This excessive shifting of items is not only time-consuming and energy draining, but it also increases the risk of injuries. Looking to increase productivity and reduce the negative effects of the current system, LIST and its partners have implemented kitting. In accordance with this technique, complementary items are ordered, packaged, or shipped together as a single kit. With the tools delivered directly, the workers can immediately start their job. At the same time, optimising transportation can reduce the number of trucks and bring down carbon emissions.

Urban freight’s contribution to the construction sector is a significant issue because even if the transportation vehicles are loaded in the most optimal way, on the way back from the site they are empty, details Berroir. Even in the best-case scenario, half of the time those trucks are carrying nothing. Filling them up with waste instead can make use of their otherwise profligate return. LIST’s choice to partner up with Polygone for a project targeting exactly this is not arbitrary because the company also specialises in waste management. This joint venture, currently under development, will see artificial intelligence used to separate and organise waste on site, taking into account the trucks’ arrival. This also saves another two trips, usually made by a waste disposal company.

Enhancing logistics is just one of the solutions for the construction sector’s emissions. But it stands out because it brings to the forefront the crux of the issue. The priority for each player in this complex sector is optimising its own activities, be it material flows, waste management or something else. This will certainly lead to good results, but as Berroir puts it "an addition of local optimums is rarely the best global solution, and instead we should optimise the project as a whole".

Teodor Georgiev

journal.lu/en/building-sustainably-through-innovation

 

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