Construction Versus Circular Economy

Despite the fact that the Construction Project Regulation (CPR 305/2011), which lists among its basic requirements the seventh stating that the construction works to be designed, built, and demolished in a way that ensures durability, reuse, and recycling of resources, was introduced more than a decade ago, the actual development of sustainable building is only taking place now as a result of political, economic, technological, and social movements. This is observed in the form of an increasing number of buildings undergoing voluntary multi-parameter evaluations verifying compliance with often stringent requirements for sustainable building, including both the construction process and future operational parameters such as BREAM, LEED, DGNB or WELL. According to the latest analyses by the Polish Association of Ecological Building (PLGBC) [6], the number of certified buildings in Poland has already reached almost 1400, with a total usable area of 28.6 million square meters, giving a 24% increase over the year. Currently, three main trends are observed in the domestic market: a dynamic increase in certified warehouse space by 4 million square meters per year, thus downgrading certified office space, which dominated all multi-criteria certifications in Poland from the very beginning; a decrease in new certifications among commercial properties, most likely due to the COVID-19 pandemic, and an increasing number of WELL awarded, with 43 analyzed during the annual period, compared to seven the previous year. It is also worth noting that currently 45% of all certified buildings in the Central and Eastern Europe region are in Poland [7].

The concept of life cycle approach involves an evaluation of the environmental impacts occurring throughout the entire lifecycle, including the upstream and downstream stages. As can be seen, the life cycle perspective is becoming an integral part of the European policy framework despite having been recognized as valuable in the construction sector for some time [8‐10]. The objective of reducing greenhouse gas emissions (GHG), also referred to as a carbon footprint, is to be distinguished at various stages of a product’s life cycle, including embodied carbon associated with the construction phase [11], is becoming the overarching goal of introduced policies aiming to improve buildings energy performance [12, 13]. GHG emissions are also one of the most frequently analyzed environmental indicators by businesses. However, it is important to remember that the life cycle analysis method allows for the study and quantification of a significantly larger number of environmental impacts than just GHG emissions. The ISO 14040–14044 series of standards set by the International Standardization Committee defines the principles, structure, and methodology for conducting a life cycle assessment (LCA) of environmental impacts. In Europe, the EN 15804 standard is used for the assessment of construction products and systems, while the EN 15798 standard is used for buildings and the Level(s) [14] assessment system is gaining increasing interest. These standards distinguish four fundamental stages in the life cycle of a product and building, including the product stage, construction stage, operation stage, and end of life stage. The benefits and burdens that occur outside the boundaries of the system, resulting directly from the possibility of recovery, reuse, or recycling of the resources involved, are also considered. The assessment of environmental impacts of construction products is becoming an increasingly common practice, although it is still voluntary [15]. For over a decade, the results of such assessments have been published by manufacturers in the form of Type III Environmental Product Declarations (EPD) that comply with the ISO 14025 guidelines [16]. In Europe, a non-profit organization called EcoPlatform [17], which brings together EPD Program Operators and LCA practitioners, has been in existence since June 2013. In Poland, the Institute of Building Technology has so far been the entity issuing EPDs and is a member of EcoPlatform. Since 2022, EPDs published by members of EcoPlatform are available in digital form [18]. There are indications that EPDs will in the future become a part of the mandatory technical assessment of products in accordance with CPR [19]. The extension of product life cycles and the change in their disposal methods at the final stage of existence are the elements that fundamentally differentiate the CE from the linear model, based on the principle of “take-produce-dispose”. Maintaining resources in the economic cycle requires focusing special attention on the final and initial stages of the life cycle. The way in which products that have been withdrawn from the operation stage are handled should allow for the maximum recovery of the resources accumulated in the product, so that they can be successfully used in the next economic cycle, in accordance with the European waste hierarchy. Adaptation abandoned buildings by providing them with new functions is an excellent demonstration of how to implement the principles of a circular economy in our daily lives. Figure 2 presents a soviet sewing factory of Tbilisi that has been revived and transformed into a multi-functional urban space (Fig. 1).

With regards to building products, the first requirements for the use of minimum recycled content are already appearing. An example that heated up the situation for Polish manufacturers importing building materials to Italy, among others, was the CAM (Criteri Ambientali Minimi) [20] requirement, which expects the use of at least 10% recycled material in polystyrene products used for insulation. It is expected that more and more such requirements will appear in line with the announced actions of the European Commission in promoting the use of recycled materials.

It is estimated that buildings are responsible for about 40% of energy consumption and 36% of related GHG emissions in the EU. Of this, 80% of energy is used for cooling, heating, and hot water. The statistics that nearly 75% of buildings in the EU are energy inefficient are additionally alarming [21]. Considering the above, acting towards improving the energy efficiency of buildings, including existing ones, plays a key role in the sector’s strive towards sustainability and circularity, which requires involvement from multiple supply chain actors. A milestone in improving the energy efficiency of the sector was supposed to be the 2010 Energy Performance of Buildings Directive (2010/31/EU), which later underwent changes, introducing several ideas for improving building efficiency, such as minimum energy performance standards (MEPs), energy performance certificates (EPCs), concepts of nearly-zero-energy buildings (nZEB), and deep renovation, as well as announcing the establishment of the Long-Term Renovation Strategy (LTRS) and the Smart Readiness Indicator (SRI). However, in practice, despite the establishment of additional support programs enabling EU member countries to cooperate, exchange experiences and best practices such as CA EPBD, in most cases, the provisions of the directive were not reflected in national regulations or only to a limited extent. EC is not giving up and despite previous experiences, has decided to tighten the regulations on building energy efficiency. Changes in the ongoing revision of the EPBD directive (COM/2021/802 final), which is part of the “Fit for 55” package [22] are very ambitious and will certainly strongly impact the further development path of the building sector. Among the basic assumptions are, among others, that from 2030 all new buildings should be zero-emission buildings, and by 2050 existing buildings should be transformed into zero-emission buildings. After long and turbulent discussions, the member states agreed to introduce minimum standards for the energy performance of existing buildings that would correspond to the maximum amount of primary energy that buildings can consume in per square meter per year. The aim is to initiate a wave of thermomodernization and lead to a gradual phasing out of buildings with the lowest parameters. Exceptions are to be made for historical buildings, places of worship, and buildings used for defense purposes. Improving the energy efficiency of building operational systems, including heating, cooling, lighting, and transitioning to clean energy sources, is crucial in reducing the energy demand of buildings and minimizing their environmental impact, and will therefore play a significant role in the shift towards a circular economy in the sector. The International Energy Agency (IEA) [23] reports that since 2020 the rate of investment in clean energy has increased to 12% totaling around USD 260 billion in 2021 in Europe.

Construction and building are among the seven key areas of the value chain listed in the revised European Commission's new Circular Economy Action Plan for a cleaner and more competitive Europe, published in 2020 (COM(2020) 98 final) [24]. This plan references the International Resource Panel (IRP) [25] suggestions that the implementation of material efficiency strategies across the entire building sector could lead to a substantial decrease in greenhouse gas emissions, with the potential for a reduction of up to 80%. The path towards this improvement is through the “Strategy for a Sustainable Built Environment,” which will ensure uniformity in important policy areas such as climate, energy efficiency (including the ‘Renovation Wave’ initiative [36]), resource management, waste management from construction and demolition, accessibility, digitization, and skills. The strategy will promote the whole life cycle perspective of buildings through:

The implementation of these postulations will undoubtedly have an impact on all actors in the supply chain, especially on construction product manufacturers who will be forced to invest in the reformulation of their products. This, in turn, will lead to the need to incur further expenditures for laboratory research necessary for these products to be admitted to the building materials market.

The legislative demand for more environmentally sustainable and circular products is also evident in the proposed new Ecodesign for Sustainable Products Regulation, which was published in March 2022 (COM(2022)142). This proposal builds upon the existing Ecodesign Directive (2009/125/EC), which only covers energy-related products, however, it is estimated that in just 2021 alone, it resulted in a savings of 120 billion euros in energy costs for EU consumers and a reduction of 10% in the annual energy consumption of the products under its jurisdiction [27]. The revised regulation proposal emphasizes the need for products that align with a climate-neutral, resource-efficient, and circular economy, reducing waste and making it the norm for products to perform well in terms of sustainability. As regards construction products, the proposal assumes that requirements will only be established if the implementation of the revised CPR regulation (COM(2022) 144 final) does not achieve the environmental sustainability objectives set forth under this regulation. The regulation will continue to apply to energy-related products, as before.

The idea of supporting and promoting sustainable investments is established in the 2020 classification system, introduced by the regulation, commonly known as the Taxonomy (2020/852/EU). It indicates six key environmental goals against which investments are to be evaluated, including: (1) Climate change mitigation, (2) Climate change adaptation, (3) The sustainable use and protection of water and marine resources, (4) The transition to a circular economy, (5) Pollution prevention and control and (6) The protection and restoration of biodiversity and ecosystems. The aim of this initiative is to differentiate between investments that cause environmental harm and those that are neutral or environmentally friendly and will contribute to achieving climate neutrality in the long term. This method of classification is intended to support financial institutions in the decision-making process and allow safe redirecting of capital without incurring additional reputational risk. The lack of clearly specified criteria for determining which investments are environmentally sustainable has led to the spread of greenwashing. The establishment of harmonized classification rules is meant to be a solution to this problem. It is worth noting that the Taxonomy does not ban investment in activities harmful to the environment but grants additional preferences to ecological solutions. Technical classification criteria regarding the first two environmental goals and not causing significant harm to any of the other environmental goals, were established in the first delegated act (2021/2139/EU) to the Regulation (2020/852/EU). In the case of infrastructure construction, all investments intended for the transport or broadly defined storage of fossil fuels have been categorically excluded. In the context of new buildings, the Taxonomy refers to the EU Level(s) [14] assessment system that supposed to be a common language for assessing and reporting on the sustainability performance of buildings. In February of this year Platform on Sustainable Finance [28] has been reactivated. The platform serves as an advisory body established under Article 20 of the Taxonomy Regulation and operates under the Commission's horizontal rules for expert groups.

Until recently, investment decision-making was based on the analysis of a company’s financial results relative to the results of entities operating in similar macroeconomic conditions. The issue of sustainable financing and investing is gaining increasing importance as investors, especially in mature capital markets, increasingly recognize that evaluating and valuing specific categories of business risks associated with companies that more transparently communicate non-financial data, specifically Environmental, Social, and Governance (ESG) data, is easier and more precise [29]. This makes these companies a safer potential investment target.

In a study conducted by Deloitte in 2022, involving over 2,000 representatives of management (CxO, C-level) from 24 countries worldwide, representing the most important sectors of the economy, nearly all respondents stated that their companies experienced the consequences of climate changes in the past year. According to the Deloitte study, environmental issues are often mentioned by survey participants as one of the three most influential factors on companies, only slightly trailing economic perspectives, and clearly ahead of areas such as innovation, talent search, or supply chain challenges. Nearly all respondents admitted that their companies experienced the consequences of climate changes in the past year, and 61% of them expect that in the next three years, they will have a significant or very significant impact on their businesses’ strategies or operational activities. 36% indicate that the impact will be moderate, and only 3% that it will be negligible or none. As a result, over 75% of CxO assess that their organizations increased spending on sustainable investment in the past year, and almost 20% indicate that it was done significantly [30]. Investing in ESG assets is so profitable that more and more companies are starting to label themselves as such, even though they have nothing to do with sustainable development. The desire to raise the ESG ratio causes companies to increasingly advertise their products as sustainable and environmentally friendly, even if it is not true. Mandatory non-financial reporting is intended to prevent this. In January 2023, the Corporate Sustainability Reporting Directive (CSRD) (2022/2464/EU) became effective, fortifying the regulations surrounding the social and environmental reporting that companies must provide. A wider range of large corporations, as well as publicly traded small and medium-sized enterprises, will now have to disclose sustainability information, affecting approximately 50,000 companies in total [31]. Companies subject to the CSRD will have to report according to European Sustainability Reporting Standards (ESRS) which are to be issued by the EC in first half of 2023. The standards encompass 84 mandatory disclosures accounting to 1144 data related to environment (E), society (S) and governance (G) (Table 1).

The new reporting requirement will provide investors and other stakeholders the information they need to assess investment risks arising from climate change and other sustainability issues.

The development of construction technologies (ConTech), including solutions that provide an access to green energy and IT solutions finding wide application in digitization and management of building resources (PropTech), are a decisive asset to enable transforming the construction industry. Providing a constant and accessible supply of safe and green energy from renewable sources would significantly bring forward the timeline for change. The traditionally conservative and resistant-to-change construction sector is beginning to recognize dozens of benefits resulting from using ConTech and PropTech technologies what paradoxically was triggered by the COVID-19 pandemic.

The flexibility of these technologies means that they are constantly adapted to the challenges facing the construction industry. An example is the increasingly widespread integration of BIM technology with LCA for efficient quantification and monitoring of a building's environmental impacts [5, 6], also in combination with modular construction, which allows work to be conducted off-site [1]. There are also examples of successful use of locally available materials, native clays and soils, as well as supplementary cementitious materials (SCM) and geopolymers for 3D printing, which is projected to become an industrial reality in the near future [32]. Meanwhile, the increasing use of digital twin technology for project management or lean management is no longer surprising anyone and is gradually becoming part of our daily lives [2, 3]. Among the most common areas of Contech investment in 2022 were project designing including planning, scheduling, specification and budgeting (40.8%), off-site and modular construction (8.3%), materials and resources marketplaces (7.9%) as well as sustainable materials (4.4%). Despite years of record investment reaching 5.38 billion USD (31% of all investments took place in Europe), ConTech saw no growth and only a slight decrease of less than 1% compared to 2021—5.4 billion USD—due to unfavorable macroeconomic conditions, which are predicted to persist throughout the current year [33].

The ability to shape the properties of polymer concrete (CPC), which constitute a large group of composite materials hidden under the acronyms PMC, PCC, PIC, PC, PFiC, causes them to have a great potential for use in construction [34]. Considering that materials and resources marketplaces as well as sustainable materials are among the most common areas of Contech investment and the fact that construction sector is becoming open to innovations like never before, it is worth considering what role polymers “in concrete” and “on concrete” may play in the sector’s quest for circularity. It is worth to mention that the production of CPC in the 1950-1970s were a manifestation of “progress” and “modernity” [35, 36]. As has been emphasized many times, one of the fundamental assumptions of CE is to extend the life span through proper design, including allowing repairs in the life cycle. An excellent example of a material that meets these requirements is concrete, which reveals its potential for self-healing and crack-healing as a result of its synergistic interaction with polymers (CPC), thus enhancing the durability and longevity of concrete structures [37‐39]. Another possibility of shaping the properties of concrete polymer composites (CPC) is the use of various modifications, including increasingly popular nanomodifications in which the use of nanometric polymer particles, characterized by a high ratio of surface area to volume, leads to improved dispersion and improved adhesion to the cement matrix [40]. The advent of lightweight polymer concrete came in response to frequent complaints about the weight of concrete, which at times leads to its rejection as a building material. The use of lightweight polymers, such as foam and expanded polystyrene, reduces the weight of concrete structures while simultaneously improving its energy efficiency [41]. Recently, there has been growing interest in using recycled plastics in CPC to reduce the amount of waste, which has fortunately received various bystander reactions. Nevertheless, researchers are exploring the use of recycled polymers as partial replacements for traditional concrete components, such as aggregates and binders [42, 43].

Given the incredibly attractive functional properties of CPC, it is worth considering what the disposal of this type of material would look like after the end of the use stage.

Is the statement that CPC using recycled materials is an innovative approach for promoting and mitigating environmental impacts with regards to the extraction of new materials and waste disposal actually true? Despite the absence of negative impact reported in the life cycle of CPC [43], it is worth answering this question by analyzing the life cycle perspective that is so promoted. Therefore, after the long phase of use resulting from the outstanding performance of CPC, including self-healing and self-cracking properties, would it be possible to effectively recover the raw material potential accumulated in these materials? In the author’s opinion, it is rather doubtful at the moment, but we can hope that the rapidly developing market for recycling-dedicated technologies and the long-life cycle of CPC structures will provide conditions for developing a solution leading to effective recovery of material resources engaged and efficient maintenance of them in the economic cycle.