Critical issues hindering a widespread construction and demolition waste (CDW) recycling practice in EU countries and actions to undertake: The stakeholder's perspective

Highlights

• Critical issues hinder a wide substitution rate of virgin raw materials with CDW.

• Desk study and the interviews highlighted the implementation state of some measures.

• Highest CDW recovery have achieved by a combination of several measures.

• Selective demolition, waste audit and MECs, traceability, taxes are effective measures.

Abstract

Construction and demolition waste (CDW) reuse and recycling represents a key point to enhance resource efficiency in construction sector and to reduce the huge volumes of extracted materials, energy consumption and waste production, which make this sector the largest resource consuming and waste producing one. Even if several alternatives for raw materials substitution have been widely investigated from a technical and economic point, several critical issues hinder a wide substitution rate of virgin raw materials with CDW valorised streams slowing down the circular economy transition. The aim of this research was to individuate and discuss these issues hindering a widespread CDW recycling practice in order to individuate actions to undertake, that can support policies and action plans. The investigation was conducted through desk research and a survey, through the administration of questionnaires and more focused guided interviews. Difficulties and barriers have been analysed and suggestions to improve waste recycling and reuse have been proposed. The state of implementation of policies, actions and best practices such as Green Public Procurement (GPP); b) End of Waste (EoW) criteria; c) pre-demolition audit; d) selective demolition; e) landfill tax; f) tax on raw material extraction; g) traceability system; h) take-back centres, have been examined and discussed. Finally, ideas and suggestions aimed at directing the correct implementation of policies, initiatives and action plans, starting from the successful experiences of some countries that could be effectively transferred in other ones and, trying to take advantage of the difficulties encountered in the implementation process, have been proposed.

Introduction

The linear approach adopted in the construction sector and, overall, in the built environment, is responsible for the consumption of a large share of natural resources including critical raw materials (Çimen 2021; Ghisellini et al., 2018a), crushed aggregates and water (Eray et al., 2019). In fact, on one side the construction sector has the largest consumption of raw materials and energy globally (Dean et al., 2016): 60% of raw materials are consumed by the building sector (Zabalza Bribiàn et al. 2011), and in particular 65% of total aggregates and 20% of metal materials (Ajayabi et al., 2019). On the other side, construction activities cause increased production of waste and pollution, by generating at the global level: the highest share of CO2 emissions (Baek et al., 2013), as 23% of carbon dioxide emissions from global economic activities are caused by the construction sector (Gopinath et al., 2018), one of the major contributors of CO2; the highest amount of waste (Akanbi et al., 2019; Pomponi and Moncaster 2017). In particular, worldwide demolition is responsible for 50% of the waste produced by the construction and infrastructure sector (Kibert 2016), causing both noise and pollution. Therefore, the building and infrastructure sector, which impacts most economic activities (Ghisellini et al., 2018b), has strong influences on the society, economy and the environment (Gencel et al., 2012).

At the same time, construction represents one of the most relevant fields of implementation for circular economy principles and practices (Smol et al., 2015). In fact, among the seven strategic sectors identified by the EU Commission in the New European Action Plan (European Commission 2020a), we find “Construction and Buildings”, thanks to its large potential and multiple opportunities. In particular, one challenge is represented by the huge materials consumption, which corresponds to nearly 50% of the material used yearly in EU (ENEA et al. 2020). At the same time, the EU construction value chain is characterized by the large quantity of waste produced each year, amounting to 372 Mt excluding excavated soils in 2020 (Eurostat 2021a), corresponding to almost 40% of the overall waste generated in Europe (Nasir et al., 2017). It is therefore necessary to ensure a higher proportion of recycling in order to improve the overall sustainability of the building sector increasing circular economy and industrial symbiosis.

In this sense, the substitution of raw materials by residues produced in other industrial sectors represents an important chance to promote circularity in the construction sector as reported by (Luciano et al., 2020) with reference to the case of Italy, where the actual raw material substitution rate is still low (6.5% in 2015) but could potentially raise thanks to a significant availability of waste from different industrial sectors, not adequately exploited yet. Industrial symbiosis offers in fact a relevant opportunity to maximize resource value in the built environment, by combining industrial ecology, recycling, use of scraps, waste materials and by-products (Çimen 2021; Cutaia et al., 2015; Luciano et al., 2016; Jacobsen 2006). Following this model, the construction sector could profitably share resource flows with other value chains, as demonstrated in the case of the stone industry (Luciano et al., 2020, Careddu and Dino, 2016), of the sugar industry (Gopinath et al., 2018), steel industry (Piemonti et al., 2021, Piemonti et al., 2022) or of the automobile industry (Mancini et al., 2014a, 2014b, 2020; Ali et al., 2019; Cossu et al., 2014) among others.

Moreover, one of the main challenges of the sector is represented by the sustainable management of construction and demolition waste (CDW). The recovery rate in Europe is very differentiated among Member States but it is on average quite high, reaching almost 90% in 2020 (Eurostat 2021b), when compared to, for instance, US or China (Zhang et al., 2022). In fact, EU is increasingly addressing the building sector with specific policies promoting circularity and material resource efficiency, in parallel to measures targeting energy efficiency. For example, the European Waste Framework Directive (European Commission, 2018a), amended in 2018, asks Member States to support the spread of selective demolition to ensure proper handling of hazardous substance as well as to facilitate re-use of building components and high-quality recycling of materials. Other important measures targeting CDW in the EU have brought to the definition of the “EU Construction and Demolition Waste Protocol and Guidelines” (European Commission 2018b), of the “Guidelines for the waste audits before demolition and renovation works of buildings” (European Commission 2018c), and the “Circular Economy principles for buildings design” (European Commission 2020b). These strategic documents address all the different stages of a building's life cycle, which should all be taken into consideration in order to boost circularity and material resource efficiency in the construction sector. In particular, the design phase is crucial to address all choices towards the minimization of material demands and waste generation, but the construction stage is relevant too, in order to avoid or at least minimize waste production, as well as to adopt sustainable materials and products, including recycled/reused ones (Altamura 2015; Honic et al., 2019). Furthermore, it is essential to define simple, effective procedures and supporting tools to help all the stakeholders involved in the building process to implement circular design, procurement and construction solutions throughout the whole building's life cycle. In this sense, the DECORUM Project (Luciano et al., 2021) developed a multi-user platform to manage and control all stages and procedures of public works, enabling all stakeholders to implement circular design choices from the setup of the tender, through design, construction, maintenance, and decommissioning.

Many studies have indeed highlighted the high potential for improvement of the material resource efficiency in the buildings’ value chain Pomponi and Moncaster, 2017, Deloitte (2017), but there are many barriers hindering the real implementation of circularity from the economic, environmental and social point of view, mainly from the technical, organizational and political perspectives (Charef et al., 2021). In particular, CDW recycling is not fully implemented due to economic and legal barriers (Ghisellini et al., 2018b) including: inadequate design standards, the low cost of waste disposal over recycling, improper city planning, the immature market for recycled waste, the lack of CDW processing (Huang et al., 2018), but also the inadequacy of policies and regulations in many countries.

To these obstacles, each member state in the EU is trying to counterpose levers by promoting specific policies and actions. The main actions fostering CDW circular and sustainable management include: Green Public Procurement (GPP), which can favour and/or enforce the use of materials and products with recycled content and the adoption of design for disassembly principles (Baiani and Altamura, 2019); End of Waste criteria, facilitating the recycling process and enhancing the trust of potential users towards secondary materials; pre-demolition audits, facilitating the management of materials allowing an early and accurate planning of the demolition phases (European Commission 2020b); selective demolition, favouring the increase of the quantity and quality of recovered materials to be destined for reuse or recycling, thus reducing materials ending as waste (EU, 2018a); landfill and/or extraction taxation, since the taxation of virgin materials can encourages the use of recycled elements, while high taxes or ban on landfilling of CDW waste can favour reuse and recycling (Cárcel-Carrasco et al., 2021); traceability systems, creating confidence among stakeholders in the value chain (Wahlström et al., 2020); take-back centres, infrastructures that can contribute to allow reuse and recycling operations (Hartwell et al., 2021). For each policy area, though, single countries are acting in their own perspective, as in the case of GPP, where 23 member states have adopted a National GPP Plan but only Italy has mandatory Minimum Environmental Criteria for construction and buildings (European Commission 2021). The regulatory framework, as well as the state of implementation of policies and initiatives, is therefore very differentiated between member states, notwithstanding the common European agenda.

Objective of the present contribution is to examine the state of implementation of policies, actions and best practices in a group of EU countries and to discuss the issues hindering a widespread CDW recycling practice, through the perception of stakeholders and of experts in the sector. The paper reports the results of research activities developed within the Interreg EU Project CONDEREFF¹ (Activity 1.4), with the aim of directing the correct implementation of policies, initiatives and action plans, starting from the successful experiences of some countries and, at the same time, trying to take advantage of the difficulties encountered in the implementation process by others.