#circular building

Those are pretty well-put-together circular walls, and massive, to boot. Very interesting that they’re prehistoric. All kinds of questions to be posed from this find - why there, why at all, who? The answers might change the current understanding of the period.

Belgium is the world champion in sorting: nowhere else is so much waste neatly separated as there. But what do you get for that? What is the impact of that sorting on our CO2 emissions, our raw materials, and our environment? And how does it work in practice?

Of the approximately 62 million tons of waste produced in the country in 2022, about two-thirds can be recycled or composted. Fortunately: this way, we avoid additional CO2 emissions, conserve scarce raw materials (making us less dependent on other economies), and create a better environment.

Less CO2, more oxygen

Making raw materials (for example, steel from ore, cement from limestone, or plastic from oil) requires a lot of energy, which means CO2 emissions. By recycling, one avoids these emissions. To illustrate: the CO2 footprint of recycled concrete is only half that of completely new concrete.

Parsimonious with raw materials

Recycling also allows us to conserve our raw materials. The ores, minerals, and rare metals in our planet are finite or becoming increasingly difficult to extract. Thanks to recycling, materials are utilised that are already present in the economy. The loop is, as it is said, "closed."

Nature says thank you

Reuse also reduces the pressure on our planet's vulnerable natural areas and ecosystems. One needs to open fewer mines or quarries, to create fewer landfills, there is less pollution from emissions in mining or refining, and there is less water consumption. Fewer harmful substances are also released into the environment, and there is less waste transport, noise, and odour nuisance.

26 million tons of construction waste

Let's take a concrete look at how recycling works, for example, for concrete. This example isn't chosen at random: the construction industry alone generates 26 million tons of waste annually in the country. No other sector performs "better."

Happily Separated

During the dismantling of a building, various waste fractions are separated. For example, concrete, brick, and tiles must be kept separate from wood, plastic, metal, and plaster. The concrete rubble is mechanically crushed, sieved, and sorted by size. Finally, dust, sand, and cement residue are also removed.

Old concrete, new foundation

Concrete recycling comes in different "levels." The lowest level produces aggregates suitable only for road foundations. At level two, the gravel can be recycled for reuse, and at level three, the sand is as well. However, only a handful of companies have already achieved this level three.

Wash me, please

Dismantling of rock wool panels in the Zwartzustervest hospital.

The construction sector is responsible for around 11 percent of national CO2 emissions and accounts for almost 50 percent of the material demand in the Netherlands, according to figures from the Het Groene Brein science network[1]. It is therefore logical that making construction more sustainable is essential for the success of our climate ambitions. 'Waste-to-product' company Renewi[2] and construction company Heijmans[3] see enormous potential for the circular economy.

“We are building houses in the Netherlands more and more energy-efficiently. More and more solar panels are being installed on roofs and our homes are increasingly better insulated. This progress means that the greatest environmental pressure of the built environment shifts: from the use of a building to the use of its materials,” says Thijs Huijsmans, senior circular construction advisor at Heijmans. “We have an enormous challenge ahead of us to keep all these materials in the cycle for much longer. Heijmans' mission is to create a healthy living environment. The use of circular materials fits in seamlessly with this. This saves CO2 and is therefore better for the earth, i.e. our living environment."

Collaboration with Renewi

Huijsmans is part of a team at Heijmans that is responsible for sustainability in the long term. “We place a vista. Not only from our own capabilities, but precisely with a view to collaboration with other parties. The entire chain is needed to achieve the sustainability challenge.”

One of those parties is waste recycler Renewi. Because various waste streams are released during both the construction and demolition of buildings. And that is a valuable source of raw materials for Renewi. “Such a collaboration starts from 'waste care': waste is released during Heijmans' activities and we come into the picture as a partner for collection,” says Marc den Hartog, director of Renewi Netherlands. “But our collaboration has continued to develop. Together we looked at how the construction sector can deal with these waste flows much more consciously. What does this waste actually consist of? Which flows can we separate? And what needs to happen if we want to reuse these waste flows as raw materials?”

Insight into waste

Heijmans receives a monthly report from Renewi in which all waste flows from all construction and demolition projects are documented. This way, Heijmans immediately sees which waste stands out and what it needs to pay attention to. “A good example is rock wool,” says Huijsmans. “We purchase this through wholesalers who receive it from the stone wool producer. Stone wool is a product with a significant environmental impact. With Renewi we have now ensured that rock wool ends up in a separate container after demolition. And Renewi in turn has agreements with the producer who takes back the material. For example, old rock wool is reprocessed in the production process to increase the share of secondary raw materials in products. This way you are working with multiple parties in the chain to complete the circle.”

Human factor

Examining a specific material or waste stream is only part of the success. “The human factor is at least as important,” says Den Hartog. “Ultimately, it is the people on the construction site who make our recycling and reuse objectives possible by separating waste at source. That is why we organise interventions and make instructions visually clear. We even work with behavioural scientists to see together how we can nudge people in the right direction.”

Huijsmans emphasizes what a challenge this sometimes is. “It is not rare for four different languages to be spoken on a construction site. Heijmans wants to be CO2 neutral, but to achieve this you must be able to explain the importance of waste separation to everyone. That is very complex. We try to keep people sharp with the help of toolbox sessions[4]."

Influencing suppliers

Another challenge is reducing waste supplied via suppliers. Many building materials are supplied in plastic, in all kinds of different colours and thicknesses. “As Heijmans, we have agreed that we will only accept packaging material that is recyclable or reusable,” says Huijsmans. This means, for example, that plastics are minimally printed with texts and logos or that packaging is made of biological material. “In the beginning we feared that such a statement would cost us money, because we could only contact a few suppliers. But in practice you notice that most suppliers adapt quite quickly. Then it is no longer an issue at all.”

Heijmans has now even stipulated in its terms and conditions that suppliers must respect the builder's sustainability strategy and actively contribute to it. “We see that more and more other builders are also asking this from suppliers,” says Huijsmans. “It takes some courage in the beginning, but ultimately you make the sector more sustainable together.”

Outflow is at least as important as inflow

When making the built environment more sustainable, a lot of attention is paid to the inflow of materials needed on the construction site. But Huijsmans sees it as his job to make the executive flow, for example in demolition projects, just as important. Huijsmans: “You naturally want to reuse all the materials that flow from a project as high-quality as possible. But there is actually one more step: first and foremost, the goal should be to simply leave materials in the building. In other words: is demolition even necessary in the first place?”

Degrowth in construction

There are all sorts of developments going on in construction that are making the sector more sustainable and limiting waste. Think of timber construction, prefab and demountable houses, the materials passport[5] and steel produced with green hydrogen. Huijsmans: “But innovations alone will not help us. Ultimately, we need to move towards a form of degrowth and less consumption, including in construction.”

“There is not one solution,” Den Hartog agrees. According to him, it is becoming increasingly relevant to include calculation tools such as CO2 pricing and true pricing in all facets of the economy[6]. “The point is that we allocate all costs associated with materials, including those associated with a negative impact on the environment. This makes the decision whether to always use new materials or to opt for secondary raw materials a much more conscious choice.”

Role of government

Den Hartog also sees an important role for the government in this. “The government, and in this case the Central Government Real Estate Agency, is also the largest real estate company in the Netherlands. They can play an exemplary role by making circularity the standard in their tenders and thus give a huge boost to demand. In addition, the government is able to determine the rules of the game, for example by requiring the use of secondary raw materials in new building materials. Finally, the quality of recycled material is no longer inferior to that of brand new materials and this demand is stimulated by further innovation. There is a huge opportunity for the Netherlands to be a leader in circular construction.”[7]

Source

Teun Schröder, Recycling en hergebruik van bouw- en sloopafval is een enorme kans voor de circulaire economie, in: Change Inc, 12-09-2023, https://www.change.inc/circulaire-economie/recycling-en-hergebruik-van-bouw-en-sloopafval-is-een-enorme-kans-voor-de-circulaire-economie-40392

[1] Het Groene Brein was founded on November 6, 2012 after a request from the most innovative, sustainable companies. These frontrunners, united in the De Groene Zaak business network, increasingly encountered questions in the implementation of their sustainability strategy for which no solution existed (yet) in the market. Questions that went further than turning on an LED lamp or separating your waste. These frontrunners hypothesized that scientists – the people with the most innovative knowledge in existence – might have the answer. With the help of DuurzaamDoor, Het Groene Brein was launched in 2012. https://hetgroenebrein.nl/over-ons/

[2] Read also: https://earaercircular.tumblr.com/post/659378159147433984/processing-150000-tonnes-of-flood-waste-will-take

[3] Koninklijke Heijmans N.V., located in Rosmalen, is a Dutch listed construction company. After the sale of activities in Belgium and Germany in 2016 and 2017, the company is only active in the Dutch market.

[4] workshops

[5] Read also: https://www.tumblr.com/earaercircular/722179599996534784/towards-a-circular-and-more-sustainable-fashion?source=share

Klark Klimabeton

You can also use it to make climate-friendly building materials. The substance is considered a miracle fertilizer. But now researchers are discovering biochar[1] as a building material that insulates houses. The search for suitable starting materials has begun.

“Terra preta” is the name of the fertile black earth, without which no grain would grow on the barren soils in the Amazon basin[2]. The special thing about the substrate: charred plant remains. They release nutrients and absorb pollutants like a sponge. Because of its reputation as a soil improver, biochar has become increasingly popular in Switzerland.

However, the Swiss soils, which according to the National Soil Observation[3] are already among the most fertile in the world, would not necessarily benefit from this. Because biochar only improves certain types of soil.

For example, the substrate increases the pH value[4] of the soil and releases plant nutrients such as phosphorus and potassium. This particularly benefits acidic and nutrient-poor soils such as those in the Amazon basin. Biochar is also useful in sandy, dry fields because it stores water, which it slowly releases back into the plants. But in Switzerland this is not necessary. Many soils already contain clay minerals - these also store nutrients and water.

Biochar is processed into insulation panels

Swiss researchers have now discovered biochar as a building material. At Empa[5], a research team led by physicist Jannis Wernery is working on a method to use biochar to insulate houses. To produce insulation panels, Wernery produces small biochar samples from plant residues in the laboratory using heat treatment and exclusion of air. The researcher then tests them for their thermal conductivity. A Chinese study provided the inspiration for this. Their authors charred bread and noticed that the resulting pieces of coal hardly allowed any heat to pass through.

The great insulating power is due to the sponge-like structure of the biochar. It is permeated by microscopically fine tubes. The trapped air conducts heat poorly and is therefore suitable as an insulating material.

When it comes to fire risk, biochar should be treated in a similar way to other plant-based insulation materials, says Wernery. The exact properties still need to be investigated. Under certain circumstances, a fire retardant will be added to insulation materials with the addition of biochar.

Different types of biomass are being tested

The Empa study aims to find the best starting material for biochar. “Using bread would be a big waste,” says Wernery. “That’s why we’re currently testing different types of biomass, such as wood, to find the material with the greatest insulation.”

In addition to choosing the right material, heat treatment also plays a role. During pyrolysis, for example, wood is heated to a temperature between 300 and 1000 degrees Celsius in the absence of air. Because there is a lack of oxygen, the wood does not burn. Instead, the heat breaks down organic compounds in the wood. Although some exhaust gases are produced, the stored carbon remains in the resulting charcoal.

Because charcoal is difficult to decompose, unlike ordinary wood, it is considered a long-lasting carbon store. And since the carbon originally comes from the CO2 in the air, it is basically a matter of removing CO2 from the atmosphere, so it is a so-called carbon sink[6].

Remove half a million tons of CO2 from the atmosphere

For the lifespan of a building, the carbon and insulation panels would be trapped between the house walls. Wernery doesn't go far enough. If a house is demolished, the biochar insulation panels should be extracted again, separated from pollutants and then introduced into the Swiss soil, as with Terra Preta. Because biochar in the soil does not decay for hundreds of years despite the weather, a good carbon sink can be created, says Wernery. Unlike mineral wool, half a million tons of CO2 could be removed from the atmosphere every year.

Whether recycling in the ground actually works depends on whether the insulation panels can be cleaned of adhesives and building rubble when demolished and whether the biochar contains toxins. Because contaminated raw materials such as varnished wood or cow manure contaminated with antibiotics could end up in the pyrolysis ovens. These pollutants would still be found in the biochar after roasting and would pollute the soil for a long time. However, the Empa team will only investigate how well insulation boards can be recycled in a second phase.

For Wernery, the two most important properties of any insulating material are initially the focus of research: how well can biochar insulate against heat and moisture? Korean researchers have already tested this in a study. To do this, they produced biochar in the laboratory from rice husks, coconut shells and bamboo. They created small tiles from the carbon powder and clay, which they then tested for their thermal conductivity using a measuring device. Tiles with an addition of 10 percent coconut biochar performed best. They conducted two-thirds less heat than pure clay tiles.

Honeycomb-shaped pads insulate well

The reason for this can be seen under the electron microscope. The coconut biochar powder is permeated by a multitude of tiny pores arranged like a honeycomb. The enclosed, microscopic air cushions are good insulators that interrupt heat conduction. Bamboo charcoal has even larger pores, but the air chambers are arranged more irregularly. This coal therefore performs somewhat worse in terms of thermal insulation.

The study also shows that all types of biochar absorb moisture. The tiles from the experiment therefore allow up to 22 percent less moisture to pass through. Instead, the carbon powder stores the moisture and allows it to slowly evaporate back into the environment. The sponge-like absorbency can be explained by the large surface area inside the biochar, which is up to 300 square meters per gram.

The key selling argument of biochar as a building material lies in the storage of carbon in the buildings. This doesn’t always have to be in the form of plaster or insulation. The Maienfeld company Logbau[7] has recently started producing Klark climate concrete[8], which is enriched with biochar during production. The concrete binds 200 kilograms of CO2 per cubic meter. The majority of the biochar is mixed as a fine powder with cement, sand, gravel and water. From the outside, only a few large black pieces of coal in the walls indicate biochar, which have a certain visual value.

The coal for this comes from waste wood such as treetops that are unusable for the furniture industry. A sister company of Logbau roasts the wood into charcoal at a temperature of 250 degrees Celsius and uses the resulting pyrolysis gases to fire the burner again. “If you add up all the steps in our process, our concrete is CO2-neutral,” says Christian Wengi, Managing Director of Logbau AG. After demolishing a house, the company crumbles the biochar concrete and uses the granules as a gravel substitute for fresh concrete. Wengi does not want to reveal the exact recipe for his climate-controlled concrete as long as the patent for it has not yet been registered.

An addition of 2 percent biochar is ideal for insulating concrete walls against heat - this is what chemical engineers from Canada discovered in a study. It shouldn't be much more than that because biochar reduces the load-bearing capacity of the concrete.

Biochar concrete also absorbs sound

The Canadian research team also discovered another property. Biochar concrete insulates against sound, especially in the middle hearing range. Depending on the amount and type of biochar used, it absorbs sounds up to 45 percent better than normal concrete.

Further studies have shown that biochar powder can replace some of the climate pollutant cement and allow the concrete to harden more quickly. But Wengi consciously doesn't advertise these properties yet. “To do this, we would first need studies and tests that test the curing and sound and heat insulation specifically for our charcoal and concrete mix,” he says.

Until then, the biochar in Wengi's climate concrete does not replace cement, but instead replaces fillers such as sand and gravel. The circular idea is more important for the climate anyway, he says. Because thanks to recycling, the carbon stored in the concrete demolition material can be put back into new houses indefinitely.

Source

Martin Angler, Pflanzenkohle verbessert nicht nur die Böden. Man kann daraus auch klimaschonende Baustoffe machen, in Neue Zürcher Zeitung,16-09-2023

[1] Biochar is the lightweight black residue, made of carbon and ashes, remaining after the pyrolysis of biomass, and is a form of charcoal. Biochar is defined by the International Biochar Initiative as "the solid material obtained from the thermochemical conversion of biomass in an oxygen-limited environment". Biochar is a stable solid that is rich in pyrogenic carbon and can endure in soil for thousands of years. The refractory stability of biochar leads to the concept of pyrogenic carbon capture and storage (PyCCS), i.e. carbon sequestration in the form of biochar. It may be a means to mitigate climate change due to its potential of sequestering carbon with minimal effort. Biochar may increase the soil fertility of acidic soils and increase agricultural productivity. Biochar is mainly used for soil application and is known to improve soil nutrient availability, aeration in soil, and soil water filtration. There exist various approaches for utilizing biochar, including but not limited to soil amendment, slash-and-char, water retention, stock fodder, and concrete additive. Biochar has been widely viewed as an environmentally positive material for soil. However, it is crucial to take into account the potential adverse effects of biochar, such as disturbing soil pH levels, or introducing harmful chemical characteristics that cause problems at the micro dimension. Therefore, caution should be exercised when considering the applications of biochar as research continues to explore the positive and negative effects of biochar.

[2] The Amazon basin is the part of South America drained by the Amazon River and its tributaries. The Amazon drainage basin covers an area of about 6,300,000 km2, or about 35.5 percent of the South American continent. It is located in the countries of Bolivia, Brazil, Colombia, Ecuador, Guyana, Peru, Suriname, and Venezuela, as well as the territory of French Guiana.

[3] Soils are one of the foundations of our existence. In order to maintain their fertility, they must be used sustainably. The Nationale Bodenbeobachtung NABO (National Soil Observation) records and assesses the temporal development of soil quality at selected locations based on chemical, physical and biological soil properties. Early detection and prediction of changes are also part of our tasks. To this end, we carry out long-term monitoring, which observes soils under their usual management. To do this, we regularly sample a measurement network from around 110 locations. We also collect data on agricultural use annually at selected locations. This allows the plausibility of the measured changes over time to be checked using material balances. In addition to long-term monitoring, NABO carries out additional studies on current issues.

[4] pH is a measure of how acidic/basic water is. The range goes from 0 - 14, with 7 being neutral. pHs of less than 7 indicate acidity, whereas a pH of greater than 7 indicates a base. pH is really a measure of the relative amount of free hydrogen and hydroxyl ions in the water.

[5] As an interdisciplinary research institute of the ETH Domain, Empa, the Swiss Federal Laboratories for Materials Science and Technology, conducts cutting-edge materials and technology research. Empa’s R&D activities focus on meeting the requirements of industry and the needs of society, and thus link applications-oriented research to the practical implementation of new ideas. https://www.empa.ch/web/empa/empa

[6] A carbon sink is anything, natural or otherwise, that accumulates and stores some carbon-containing chemical compound for an indefinite period and thereby removes carbon dioxide (CO2) from the atmosphere. These sinks form an important part of the natural carbon cycle. An overarching term is carbon pool, which is all the places where carbon can be (the atmosphere, oceans, soil, plants, and so forth). A carbon sink is a type of carbon pool that has the capability to take up more carbon from the atmosphere than it releases.

[7] https://logbau.swiss/baustoffe/

Simon Kronenberg (42), CEO of Holcim Central Europe West, talks about transparent milestones on the way to net zero, new technologies for capturing and storing CO2 and the fact that concrete - the most commonly used building material - has an impressive recycling rate.

The global building materials group Holcim[1] is perceived by the public as not very environmentally friendly. You have been working for the company for 16 years – how has it changed for the better during this time?

Simon Kronenberg: As a manufacturing industry, our industry is energy and resource intensive, especially the production of cement. Thie latter in turn is the binding agent for producing concrete. We have therefore invested heavily in sustainability since the 1990s. In recent years, we have achieved a lot, particularly in decarbonization and promoting the circular economy, and as a driving force in the domestic market, we have made a significant contribution to solving social challenges such as resource scarcity or climate change. Sustainability is now an integral part of our business.

Can you back this up with facts and figures?

SK: Let's take the CO2 reduction per ton of cement as an example: here we have saved over 35% to date and are still at 520 kilos of CO2 net. Our goal in Switzerland by 2030 is to save 380 kilos of CO2, another 25%. In addition, we are constantly developing new materials that are CO2-reduced, reusable and 100% recyclable. For example: “carbon pre-stressed concrete”, concrete elements with prestressed carbon reinforcement. Depending on the construction, the high-performance, extremely thin concrete slabs enable significant material savings and reduce the CO2 footprint by up to 75%. With products such as Airium[2], a mineral insulation material, we also contribute to the sustainability of the use of buildings.

What about recycling?

SK: The building materials industry offers huge potential for recycling waste – and we are doing our part. To give you an idea of ​​the magnitude: we recycle around 4 million tons of various types of waste every year, such as excavation, concrete and mixed demolition, and industrial waste.

What role does concrete play in this?

SK: Concrete is the most important building material of our time, it enables our modern infrastructure. If you consider that we use more than 60 million tons of building material in Switzerland every year - almost 40 million tons of which are concrete - this material must be recycled in the interests of sustainability. We Swiss are considered the world champions of PET recycling; this value is 82%. However, the recycling rate for concrete is already 85%. And by ensuring high quality, especially with the preparation of the dismantled concrete and its later use, concrete can be recycled almost infinitely.

Holcim Switzerland published an environmental report last year and set clear interim goals for 2030 - which ones?

SK: We are aware of our social responsibility and know that time is of the essence. Last year we published our environmental goals and discussed them intensively with our partners. The publication consists of eight domains of action with clearly defined milestones, for example in the areas of decarbonization, circular economy, sustainable logistics, renewable energy or “carbon capture, utilisation and storage”, or CCUS in short[3]. This is how we reduce CO2 from the quarry to the construction site or by recycling building materials. The greatest potential for CO2 reduction lies in reducing the clinker share in the cement. But it is also a fact that, in addition to conventional technologies, we need to develop and implement innovative approaches such as CCUS in order to get to net zero.

On the capture, use and storage of CO2: Where does Holcim Switzerland stand regarding CCUS?

SK: We are developing around ten pilot projects in different phases, and at group level there are over fifty. By 2030, we want to capture around 20,000 tons of CO2 per year in our cement plants in this country. The goal is to either transform this CO2 into a product or store it in a storage facility. The prerequisites for the successful implementation of such projects are, in particular, the legal framework, the required domestic storage capacity, access to foreign storage facilities and the acceptance of the population.

Can you give concrete examples of how CO2 can be integrated into a product?

SK: There are already various CO2 applications, for example as carbon dioxide in mineral water or for the chemical industry. As far as concrete is concerned, we now have a system with which we can fumigate 100,000 tons of demolished concrete with CO2 and thus store around 10 kilos of CO2 per cubic meter of concrete. This product is called ECOPact RECARB.[4]

Keyword: resource-saving products: what are the innovations ECOPact and Susteno developed by Holcim Switzerland?

SK: ECOPact is our sustainable and resource-efficient concrete product family. Susteno[5] is the world's first cement that consists of 20% recycled material. We are very pleased with how the sales volumes of these products are developing. This shows that the demand is there. We have set ourselves the goal of having converted around 50% of our portfolio to these resource-saving products by 2030.

How essential is digitalisation for achieving your sustainability goals?

SK: Of central importance, in three main aspects: on the customer side or in construction, it is important that we go as paperless as possible and use new technologies such as 3D printing or prefabrication. The second big topic is logistics, in order to plan and deliver more sustainably. The last important point is the digitalization of our production – both in terms of automation and innovation. Our cement plant in Untersiggenthal[6] is a pilot for the group-wide “Plant of Tomorrow” project, which aims to make cement production more efficient and sustainable. As part of this project, for example, we use fully autonomous, electric tippers, so-called e-dumpers, in the quarry or special drones for maintenance work at high altitudes.

Despite all the measures, the cement and concrete industry remains resource-intensive. Why can their net zero vision still be achieved?

SK: We are confident about our successes to date and our comprehensive innovation projects, particularly to reduce CO2 and promote the circular economy. We also see increasing demand for sustainable building solutions and resource-saving products. As already explained, in order to achieve our goals we also need CCUS technologies, which we are working hard to implement. Switzerland currently has to handle around 36 million tons of CO2 annually. For this we need new approaches such as capturing, using or storing CO2.

What is the level of social awareness when it comes to the topic of sustainable building?

SK: We are on the right track. In order to create further awareness in society, we promote public discussions about sustainable building solutions. We also strengthen collaboration and knowledge transfer between different actors: from research institutes to architects to developers. At the same time, we seek dialogue with startups.

The vision of Holcim Switzerland is: “By 2050 we will produce climate-neutral and fully recyclable building materials.” Can you reach net zero faster?

SK: That is our ambition. Not only are we on schedule, we are often one step ahead. In Switzerland we are in the fortunate position of having extremely competent and motivated employees who are passionate about making our vision a reality. We come to work in order to find solutions. But we can't do it alone. Net zero is possible if all of us have a common vision, and collaborate with all partners across the region and use industrial synergies.

Source

Norman Bandi, “Wir kommen zur Arbeit, um Lösungen zu finden», in Neue Zürcher Zeitung, 3-09-2023; https://www.nzz.ch/themen-dossiers/zukunft-bauen/wir-kommen-zur-arbeit-um-loesungen-zu-finden-ld.1754051

[1] Holcim (Schweiz) AG, based in Zurich, is one of Switzerland's leading providers of innovative and sustainable construction solutions in the areas of building construction, civil engineering and infrastructure. The company produces concrete, gravel and cement at 55 locations across Switzerland and recycles demolition materials into resource-saving products. Sustainability is at the centre of business activities. Holcim Switzerland is a subsidiary of the globally active Holcim Ltd and employs around 1,200 people in 3 cement plants, 16 gravel plants, 36 concrete plants and several recycling centres.

[2] Airium® is a versatile mineral insulating foam that offers a solution to make buildings sustainable and energy-efficient in use. Today, it is available in 9 countries worldwide for both new build and renovation projects to ensure an ideal thermal comfort, be it for cold temperatures or heat waves. With Airium®, we are accelerating the uptake of insulation in both developed and emerging economies. It can be used in a simple way for many applications: from sub-screed floor insulation to the filling of concrete blocks to roof terraces, attics or lightweight void filling. It is composed mostly of air (up to 95%), water, a cementitious base binder and several additives in small proportions. It is then mixed in a special machine to create the insulating foam at the exact density required. https://www.airium.com/about

[3] CCUS involves the capture of CO2, generally from large point sources like power generation or industrial facilities that use either fossil fuels or biomass as fuel. If not being used on-site, the captured CO2 is compressed and transported by pipeline, ship, rail or truck to be used in a range of applications, or injected into deep geological formations such as depleted oil and gas reservoirs or saline aquifers. https://www.iea.org/energy-system/carbon-capture-utilisation-and-storage

[4] ECOPact+ and ECOPact RECARB are concretes based on Holcim Susteno 4, an ecologically mature, high-quality cement. Using the latest technologies, a solution was developed to reuse the fine fraction of the processed mixed granules as part of the new cement. This innovative development conserves natural resources, saves landfill space and reduces CO2 emissions by partially replacing cement clinker. https://www.holcimpartner.ch/de/produkte/beton/ecopactplus

[5] Susteno is the world’s first resource-saving cement with 20 percent recycled construction and demolition materials (CDM) inside. Susteno is made possible by processing and upcycling materials from demolition projects, resulting in a cement that closes the loop on CDM to build new from the old and preserve nature. The quality requirements of the recycled aggregates for the production of Susteno are very high, including strict acceptance criteria regarding the size and humility of the granulates, as well as chemical and mineral requirements and components that need to be excluded. The strict quality management includes testing of the cement and concrete beyond the standard, ensuring an efficient and high-quality cement that can be used in all building construction applications. https://www.holcim.com/what-we-do/our-building-solutions/cement/susteno

The use of ecologically produced materials is also gaining in importance in construction. An alliance for sustainable building now wants to speed up the process in Mecklenburg-Western Pomerania.

The economy in Mecklenburg-Western Pomerania[1] has called on the federal, state and local authorities to set a good example in ecological and sustainable construction. According to contract award statistics, only just under six percent of public construction contracts nationwide in the first half of 2021 were tied to sustainability criteria. A share of little more than ten percent can be expected for 2022. "There is still room for improvement," emphasized the President of the MV Chamber of Architects, Christoph Meyn, recently in Schwerin[2].

The occasion was the presentation of concrete recommendations for action by the Alliance for Sustainable Building in Mecklenburg-Western Pomerania[3], that was founded in October 2022. In addition to the Chamber of Architects and Engineers, its members include the State Building Association[4], the Chambers of Crafts and Industry and Commerce, the BUND environmental protection organisation[5] and universities and colleges in the North-East.[6]

The alliance calls for better legal framework conditions for the introduction and use of ecological building materials. The consistent use of sustainable building and insulation materials is intended to reduce the heat and electricity requirements of buildings. By promoting regional material cycles for components and materials, the use of building materials should be reduced and added value in the state increased. In addition, the qualification of personnel in construction companies and planning offices as well as in authorities is to be promoted.

Instead of insulating panels made of Styrofoam or glass fibres, natural materials such as wood fibres, seaweed, straw or hemp should be used more, said the President of the Chamber of Engineers, Gesa Haroske. In addition, it is important to process building materials and reuse them for future generations, taking into account the limited resources and burdens. "Today's students are demanding sustainable construction," she said. Awareness of this is growing.

"We can only build more ecologically if we move from talking to doing business," warned the general manager of the Schwerin Chamber of Industry and Commerce, Siegbert Eisenach. Possibilities for this should be shown to the industry and at the same time ways should be opened up to the latter to make it fit for the future. "We want to be a pioneer here in Mecklenburg-Western Pomerania," said Eisenach. The transformation and many different interests, but inevitable. "This path will not be easy," admitted Eisenach.

According to Meyns, the increasing costs for energy, transport and recycling must also be taken into account in future construction. "This has long been an issue for companies, and builders are asking about it more and more," he said. Recently, the federal government's plans for a new heating law had caused heated debates because homeowners feared major financial burdens with the originally planned specifications for the conversion to emission-free heating systems.

Source

Dpa, Öffentliche Hand in Vorbildrolle, in: Süddeutsche Zeitung, 18-7-2023 https://www.sueddeutsche.de/wirtschaft/nachhaltiges-bauen-oeffentliche-hand-in-vorbildrolle-dpa.urn-newsml-dpa-com-20090101-230718-99-444119

[1] Mecklenburg-Vorpommern also known by its anglicized name Mecklenburg–Western Pomerania, is a state in the north-east of Germany. Of the country's sixteen states, Mecklenburg-Vorpommern ranks 14th in population, It covers 23,176 km2 making it the sixth largest German state in area, and 16th in population density. Schwerin is the state capital and Rostock is the largest city. Other major cities include Neubrandenburg, Stralsund, Greifswald, Wismar and Güstrow.

[2] Schwerin is the capital and second-largest city of the northeastern German state of Mecklenburg-Vorpommern as well as of the region of Mecklenburg, after Rostock. It has around 96,000 inhabitants, and is thus the least populous of all German state capitals.

[3] In the course of climate change, in addition to the emissions caused during operation, the entire CO2 footprint and location of buildings is increasingly coming into focus and makes an economic analysis over the entire life cycle necessary. Numerous actors in Mecklenburg-Western Pomerania have been active in this area for years or even decades and repeatedly come up against obstacles that have so far slowed down the dynamic development of sustainable construction. https://www.ihk.de/schwerin/standortpolitik/regional-und-stadtentwicklung/hochschulen-westmecklenburg/allianz-fuer-nachhaltiges-bauen-in-mv-5628018#:~:text=Die%20Allianz%20f%C3%BCr%20nachhaltiges%20Bauen,Interessierte%20k%C3%B6nnen%20der%20Gruppe%20beitreten.

[4] In German: Landesbauverband

[5] In German: Umweltschutzorganisation BUND

The Satellite, Dutch Central Bank

In the longer term, building with recycled, circular materials is not only better for the planet, but also cheaper. During the Provada trade fair, experts will try to convince the financial and real estate world of this. "We're still looking too much at the initial investment."

According to the latest Circle Economy report[1], although 88 percent of construction and demolition waste in the Netherlands is recycled, it is mainly used for low-value applications, such as road foundations. Only 8 percent of the building material used is actually circular.

Image is incorrect

Technically, much more can be built in the Netherlands with circular materials such as wood, concrete or aluminum. Then why doesn't that happen? Too expensive is often the conclusion of developers, banks and property owners. That picture is incorrect. We need to look much more at the value and costs of buildings on the longer term, the saved CO2 emissions, energy and raw materials, says Martijn Veerman, specialist circular facades at Alkondor[2]. "We are still looking too much at the initial investment. What does something cost now? Can I afford it now? But we don't consider a period of thirty years; looking at the adaptability or the CO2 impact," he says.

Panel discussion on Provada

During the Provada trade fair[3], he will be part of a panel[4]  with other experts on Wednesday 14 June entitled 'The value of circular materials in the business case'. Experts, from developers to architects and manufacturing companies, who focus on circular products. They want to give construction companies, developers, property owners, investors, banks and other visitors new insights into the circular economy. “It requires a completely different way of thinking,” he says. “Per definition, it is about a longer lifespan. It's about flexibility. If you come up with something today, how can you change it over time? You now see a lot of vacant real estate in the offices sector, while there is a huge housing shortage. This has to do with laws and regulations, but also with the technically limited possibilities for a refurbishment without stripping everything for recycling. Higher requirements are set for the quality of homes and less for office buildings. That is not so easy to upgrade. Moreover, stripping and rebuilding is extremely expensive.”

Nederlandsche Bank as an example

According to him, there is a world to be won by designing buildings in such a way that they can be taken apart more easily and the parts can be reused later. This has hardly been thought of in the past thirty years. As a result, the quality of buildings at the end of their lifespan is poor. A positive exception is the headquarters of De Nederlandsche Bank (DNB) in Amsterdam, The Satellite[5] . New Horizon[6]  and Re:Born have completely dismantled the building, after which all parts are given a second life. For example, the facades. Veerman: “There we saw that the DNB delivered gigantic quality in the 1980s, when the tower was built. Those elements are perfect for reuse. Only there was the problem that the connections were difficult to get apart and a lot was glued together with adhesive to make everything wind and airtight. Alkondor carried out research and tests on a number of facade elements in its factory for RE:Born and New Horizon. The conclusion: more quality offers more value in the future. We could literally reuse that building one-to-one. Unfortunately, practice shows that it is a huge challenge.”

Aluminum mining from buildings

Veerman works for Alkondor, De Groot & Visser and Wicona's 'daughter company' Ciskin[7], the Circular Facade Company, among others. That designs circular facades of recycled aluminium. “Everyone is shocked by that, because that is CO2-intensive. But our partner Wicona[8] harvests this material from buildings and converts it into a premium façade product of the same quality,” he explains. “Wicona is part of the Norwegian Hydro[9], one of the largest aluminum producers in the world. They have discovered that their mine to dig in is no longer the bauxite mine, but the built environment.”

Because aluminum is made at high temperatures and therefore with a lot of energy, this produces a lot of climate benefits. Wicona processes 200,000 tons of material annually and reduces it to pure, high-quality aluminum. This results in global CO2 savings of 85 percent compared to traditional aluminum from bauxite.

Circular value not included in valuation

If green hydrogen can be used for the remelting process, that percentage will increase further. But according to Veerman, it is mainly about the continuous reuse of aluminum facades and extending the technical lifespan. “We are strongly committed to this with Ciskin. But banks and investors are shocked by this and say: I won't do that. I only see risks. Ultimately, this facade is about 10 percent more expensive than a traditional cavity wall or a timber frame construction element. So the value of that circular, detachable facade with a longer lifespan is never found back in an appraisal or financial plan. We are never looking beyond twenty or thirty years nowadays.”

Circular construction cheaper

Subsidies are available for this type of circular construction product, which equalizes the price somewhat. But according to Veerman, building with circular materials is cheaper if you take the so-called Total Cost of Ownership (TCO) into account. These are all costs that an owner incurs during the life of a building or home. So not only during construction, but also when adapting to stricter environmental and climate regulations that are coming. Or during the demolition phase and the removal of rubble and waste. The total cost of housing construction is on average 2.4 times higher than the initial construction investment. Because CO2 emissions are becoming more expensive and the EU is imposing stricter environmental and climate regulations, sustainable buildings with circular materials are cheaper in the long term. And buildings with primary raw materials more expensive. Governments can also impose further requirements. For example, since this year the Dutch Central Government Property Agency[10]  has been setting stricter requirements for the use of circular materials when tendering renovation and construction projects for the government.

Source

André Oerlemans, Circulair bouwen te duur? Niet als je er anders naar kijkt, in Change Inc, 9-06-2023, https://www.change.inc/infra/circulair-bouwen-te-duur-niet-als-je-er-anders-naar-kijkt-40045

[1] The Dutch built environment might be resting at the centre of a perfect storm—but circular strategies can help it meet its environmental goals as well as the social need for new housing, while reshaping the employment landscape. The Circularity Gap Report for the Built Environment in the Netherlands shows how.   https://www.circularity-gap.world/sectors?_ga=2.145431920.559754559.1686412078-2025830176.1679753316#download

[2] Alkondor Hengelo is a leading facade specialist in the Netherlands. The facade is the business card of your building and represents a significant part of your investment. In addition, the facade makes an essential contribution to the energy saving of a building. The functions of the facade have a great influence on the well-being of the building users. https://www.alkondor.nl/

[3] PROVADA is known for being the largest real estate fair in the Netherlands. With more than 200 exhibitors from the real estate sector - from project developers, investors, builders, architects to financiers, advisers, brokers and housing associations - and more than 70 municipalities, provinces and the national government, the public sector is well represented at this real estate fair where the public-private connection is central to programming. Every year in June, PROVADA can be found in RAI Amsterdam for a three-day exhibition with an attractive programme, physical stands and networking opportunities. https://www.provada.nl/nl/over-ons/

[4] Circular building is great! However, circular construction is too expensive from a linear point of view! But is this correct? Shouldn't a circular development be approached 100% differently? And how do we implement this in the current real estate market? Or: “How can investors and property owners create value with circular materials?” With a very diverse integral panel, we deal with these questions in an interactive way with the audience!https://www.provada.nl/nl/provada-2023/programma/view/1653/de-waarde-van-circulaire-materialen-in-de-business-case?_ga=2.254614988.559754559.1686412078-2025830176.1679753316

[5]The Satellite, the round tower of the office building of De Nederlandsche Bank, will be given a second life at a different location in Amsterdam. The initiative came about through the collaboration of Strukton Worksphere with partners New Horizon and RE:BORN. On Tuesday, the so-called constructive dismantling of the tower at its current location started. After the parts have been carefully dismantled, they will soon be used for the construction of a new building elsewhere in the city. https://www.dnb.nl/algemeen-nieuws/nieuwsbericht-2020/de-satelliet-de-ronde-toren-van-de-nederlandsche-bank-krijgt-tweede-leven/?_ga=2.153833980.559754559.1686412078-2025830176.1679753316

[6] Read also: https://www.tumblr.com/earaercircular/650959780738924544/recycling-concrete-makes-a-big-leap-forward?source=share

[7] How does a Ciskin facade work? The design, development and realization of new structures, or the renovation/transformation of existing structures increasingly requires a well-thought-out sustainable and/or circular concept. With regard to the facade, the Circular Facade Company has the solution for you. We offer a circular facade concept that provides an answer to the circular principles and challenges you encounter when designing buildings.https://circularfacadecompany.com/?_ga=2.245710144.559754559.1686412078-2025830176.1679753316

[8] The deep-rooted idea of sustainability is fulfilled in a unique way by the use of recycled aluminum from Hydro. Hydro is pushing the boundaries for low-carbon aluminum and using post-consumer scrap to make recycled alloys and products. The use of sustainable and recyclable materials with a low carbon footprint contributes to a reduction in global emissions and creates products for a more circular economy. Hydro CIRCAL is a range of premium aluminum made with a minimum of 75% recycled post-consumer scrap. Hydro CIRCAL has a CO2 footprint that is one of the lowest in the world: 2.3 kg CO2 per kilo of aluminium, certified by an independent third party and accompanied by an Environmental Product Declaration (EPD).

[9] Norsk Hydro ASA (often referred to as just Hydro) is a Norwegian aluminium and renewable energy company, headquartered in Oslo. It is one of the largest aluminium companies worldwide.It has operations in some 50 countries around the world and is active on all continents[citation needed]. The Norwegian state owns 34.3% of the company through the Ministry of Trade, Industry and Fisheries. A further 6.5% is owned by Folketrygdfond, which administers the Government Pension Fund of Norway. Norsk Hydro employs approximately 35,000 people.Hydro had a significant presence in the oil and gas industry until October 2007, when these operations were merged with Statoil to form StatoilHydro (in 2009 changed back to Statoil, which is now called Equinor).