Reducing construction and demolition (C&D) waste is of paramount importance due to its significant environmental, economic, and social implications. The construction industry is a major contributor to waste generation, and addressing this issue is crucial for sustainable development and that is why it is necessary to move towards a more sustainable and circular construction sector.
How is circularity in construction defined?
Currently, the definitions of circularity and sustainability applied to the construction field are not agreed upon and therefore their evaluation is complicated. According to the Transition Agenda for Circular Construction Economy of the Netherlands, Circular construction is defined as “The development, use and reuse of buildings, areas and infrastructure without unnecessarily exhausting natural resources, polluting the living environment, and affecting ecosystems. Construction in a way that is economically sound and contributes to the well-being of humans and animals. Here and there, now and later.”
Other definitions such as the World Business Council for Sustainable Development one, focus on the material aspect and specifies strategies, considering that “a circular building optimizes the use of resources while minimizing waste throughout its whole life cycle. The building’s design, operation and deconstruction maximize value over time using:
• Durable products and services made of secondary, non-toxic, sustainably sourced, or renewable, reusable or recyclable material;
• Space efficiency over time through shared occupancy, flexibility and adaptability;
• Longevity, resilience, durability, easy maintenance and reparability;
• Disassembly, reuse or recycling of embedded material, components and systems;
• Life-cycle assessment (LCA), life-cycle costing (LCC) and readily available digital information (such as building material passports).
A sustainable building, according to widely accepted definitions and standards, is designed, constructed, and operated with a focus on minimizing its environmental impact while promoting long-term economic viability and social well-being. Thus, we consider the circularity of a building to be part of its sustainability”.
But how to measure circularity and sustainability in a construction or infrastructure?
Currently this search for indicators is very relevant since other projects and initiatives with which RECONMATIC has established synergies carry out similar or parallel activities (CircularB COST Action, Reincarnate).
Defining indicators of circularity and sustainability in the construction sector is imperative for steering the industry towards a more responsible and resilient future. These indicators serve as compass points, guiding stakeholders in assessing and measuring their progress toward sustainable and circular practices. By establishing clear metrics, such as the percentage of recycled materials used, energy efficiency ratings, and waste reduction targets, the construction sector can quantifiably track its environmental impact. Moreover, these indicators act as catalysts for innovation, encouraging the adoption of eco-friendly technologies and practices. Below the followed methodology is presented.
Methodology Steps
Definition of dimensions and subdimensions of indicators
Literature review
Selection of indicators
Validation of indicators
STEP 1: Definition of dimensions and subdimensions
The objective of this step is to establish a framework that would organize the types of indicators and at the same time provide a base of fundamental aspects that must be considered regarding the sustainability and circularity of a building/infrastructure. To do this, we start from five major dimensions, the three of main areas of sustainability: Environmental, social and economic. We add other dimension to cover specific aspects of a professional activity, the technical dimension, and another dimension related to the management of a sector in which various actors influence: the governance and management. We end up, therefore, with the following five dimensions: Environmental, social, economic, technical, and management/governance.
Within these dimensions, some subdimensions are established to collect the different aspects that they encompass. For this subdivision we draw on literature, reviewing several documents, such as: guides, certifications, regulations and tools. Finally, the resulting dimensions and subdimensions are the following:
Table 1: Dimensions and subdimensions of sustainability and circularity
DIMENSIONS | SUBDIMENSIONS |
ENVIRONMENTAL | Impacts (including noise and vibrations) Materials (including byproducts) Water Waste Natural capital Energy Emissions |
SOCIAL | Healthy & comfortable interiors Health & Safety (workers, users and society) Job creation and local opportunities Resilience Knowledge, skills, and awareness Acceptance Impacts on the neighbourhood Cultural heritage |
ECONOMIC | Costs (includes life cycle costs and external costs) Benefits (including social return on investment) Incentives and funding Viability and risks Circular business (including effects on local economy) Value chain |
MANAGEMENT AND GOVERNANCE | Data availability and transparency Policy and legislation Management mechanism Maintenance and life extension Stakeholders’ engagement Social responsibility (equity, human rights, accessibility) Innovation |
TECHNICAL | Design Tools and digital systems Infrastructure availability Quality |
STEP 2: Literature review
The first step was to compile a list of the most relevant reference documents, of the following types: certifications, standards, tools, guides, policies and regulations and other summary documents of circularity and sustainability indicators (Table 2). After agreeing on the documents, we reviewed them to collect the indicators that were mentioned. A list of up to 700 indicators was obtained.
Table 2: List of documents reviewed
Type of document | Specific document |
1. Sustainable construction assessment and certification schemes | 1.1 LEVEL(s), 1.2 LEED, 1.3 BREEAM, 1.4 ENVISION Protocol, 1.5 Other national schemes: Czech Republic, Spain, UK, Cyprus, Italy, Greece, China. |
2. Standards related to sustainability in buildings and civil engineering works | 2.1 CEN TC 350, 2.2 ISO 14040-44, 2.3 ISO 21930, 2.4 ISO 21928-2:2023, 2.5 ISO 21929-1:2011, 2.6 ISO 15804, 2.7 ISO 15978, 2.8 ISO 29887, 2.7. 2.9 ISO/PWI 7016, 2.10 ISO/DIS 59020, EN 15643:2021. |
3. Existing tools and databases for Circular Economy and Social Assessment | 3.1 Katche project, 3.2 Social LCA Hypobrick, 3.3 Symbinet, 3.4 Circular Start, 3.5 Circularity Assessment tool, 3.6 Circular benchmark tool , 3.7 Measuring the circular economy, 3.8 Circulytics, 3.9 Circular Building Toolkit |
4. Guidelines | 4.1 EU Construction and demolition waste management protocol. 4.2 Guidelines for the waste audit before demolition and renovation works of buildings. |
5. Policies, regulations | 5.1 European waste framework 5.2 CE proposal Ecodesign for Sustainable Products and Construction Products Regulation 5.3 EU Circular Economy Action Plan 5.4 Circular Economy Monitoring Framework 5.5 European Circular Economy Stakeholder Platform 5.6 Ecodesign Directive 5.7 European taxonomy 5.8 European Green Deal 5.9 Product Environmental Footprint (PEF/DAP) 5.10 Waste Framework Directive 5.11 Other national schemes |
6. Indicators of sustainability or circularity | 6.1 Circularity Indicators (Ellen McArthur Foundation and Granta) 6.2 How to Assess Product Performance in the Circular Economy? Proposed Requirements for the Design of a Circularity Measurement Framework 6.3 Circular economy indicators for buildings and housing 6.4 A framework for circular buildings indicators for possible inclusion in BREEAM 6.5 The circular built environment playbook (W-GBC) |
STEP 3: SELECTION OF INDICATORS
The goal of this screening process is to eliminate irrelevant or duplicated indicators, group similar ones, and rename the resulting indicators to align with the tool's structure. The screening process for the approximately 700 indicators gathered from the literature was based on the identification and application of specific criteria. These criteria were discussed during a workshop with a portion of the Reconmatic consortium. Ultimately, the screening criteria were as follows:
Duplication: Removal of duplicate indicators
Similarity: Grouping of similar indicators
Relevance: Elimination of indicators unrelated to the tool's objective
Renaming: Adjustment of indicator expressions to align with the expected response type in the tool.
As a result, 175 indicators were obtained, with approximately 20-30 in each dimension. The environmental dimension, particularly the material and waste subdimensions, is the most populated, as expected given the nature of the subject matter we are addressing.
STEP 4: VALIDATION OF INDICATORS
A double validation process has been proposed. The first validation is carried out by project partners, wherein at least three individuals are assigned to validate each indicator by addressing the following questions:
Is this indicator well expressed?
Is the answer useful for guiding practices towards circularity?
Is it too broad or too specific?
Are all important issues/topics covered?
Is any indicator missing?
Is any innovation towards circularity/sustainability not covered by the solutions?
Feedback was collected, and relevant modifications were made.
In the second validation, the aim is to validate the indicators with various stakeholders in the construction sector. This validation, crucial for grounding the indicators in real practices, will take place in each of the countries within the consortium during a specific workshop. The results will be integrated, and adjustments will be made accordingly. Following the integration of results from external validation, the final indicators will serve as pivotal components, feeding into an assessment tool that guides the construction industry towards sustainability and circularity practices.
Conclusion
In an era where sustainability is a key global concern, and circularity in construction is under review, these indicators will serve as pivotal components, feeding into an assessment tool that guides the construction industry towards sustainability and circularity practices. This tool will hopefully collaborate in pushing the sector to embrace methods that minimize environmental degradation, reduce resource depletion, and contribute to a more circular and sustainable built environment.
You are invited to contact us if you are interested in participating in the international workshop for the tool validation in September 2024 and subscribe to our newsletter to receive the results of the project and more news directly in your mailbox. Stay tuned with our social media (@reconmatic) for more updates on our activities!
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