Methodology to assess the circularity in building construction and refurbishment activities

Circular economy in construction - findings from a literature review

The paper aims to enable a comprehensive definition for a Circular Economy (CE) that will support its effective introduction in the building and construction sectors. According to the European Commission (EC), the building sector in 2020 accounted for 40 % of the primary energy demand in the European Union (EU) and 37 % of its greenhouse gas emissions. Thus, the sector can play a crucial role in decarbonisation and hence in achieving a zero-emissions future in response to climate change. A CE aims to harmonise economic growth with environmental protection and is based on the concept of closing the loop with minimal practical waste as in a natural ecosystem. The adoption of CE concepts is therefore seen as a feasible response to climate change through the deployment of more sustainable construction processes that significantly reduce the need for natural resources by maximising recycling and reuse. However, and despite the recognition of the potential of a CE in relation to sustainability issues, the adoption of a CE model within building and construction sectors is challenging because of the wide range of aspects and priorities which are reflected in the diversity of definition resulting in a narrow and limited adoption. There are currently many definitions of CEs as related to building and construction in the literature, creating confusion and preventing effective implementation. The study presented here intends, using a comprehensive literature review as its basis, to define the key domains of a CE on which to align a concise and accurate definition that will enable effective application in the building and construction sectors. The research also aims to identify current research gaps and barriers to contribute to the future of CE research in the building sector and thus drive the implementation of CE projects to mitigate the effects of climate change and support the achievement of the UN Sustainable Development Goals (SDGs) by laying the foundations for a novel and forward-looking approach to circularity based on properly established, defined and understood principles of CEs.

Construction and demolition waste framework of circular economy: A mini review

As the demand for materials continues to increase and building lifespans shorten, the construction industry faces mounting pressure to reduce its material and environmental impacts. Mismanagement of construction and demolition waste (CDW) can have severe environmental consequences. To address this, material recovery and circular economy approaches offer significant potential for reducing construction waste through the sustainable use of resources. Existing circular economy and material recovery models that prioritize recycling and reuse efforts demonstrate a sustained commitment to supporting circular practices in the construction and demolition sector. The goal is to minimize waste production, which poses environmental challenges such as raw material shortages and sustainability concerns. Using Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement for recruiting relevant literature, this mini review aims to identify the obstacles to implementing circular economy practices in the construction industry, while exploring opportunities for material recovery and circularity. The ultimate aim is to facilitate a fair and smooth transition towards sustainable development, while addressing environmental, social and economic barriers. A more sustainable and circular approach to building construction and management can be attained by considering all the aspects of the CDW cycle, resulting in significant benefits for the environment and society as a whole.

The Role of Life Cycle Structural Engineering in the Transition towards a Sustainable Building Renovation: Available Tools and Research Needs

Given the current climate emergency and the ambitious targets of carbon emissions reduction, retrofitting strategies on existing buildings typically include reducing energy demand, decarbonising the power supply, and addressing embodied carbon stored in materials. This latter point redefines the role of engineers in the transitions towards a sustainable construction sector, being they responsible for designing low impact, sustainable and carbon neutral solutions. A Life Cycle Structural Engineering (LCSE) approach, inspired by the principles of Life Cycle Thinking (LCT), should thus be adopted for the sustainable renovation of existing buildings. Only recently have pioneering approaches been proposed, tackling multifaceted buildings’ needs, such as those related to energy consumption as well as seismic safety, but often disregarding LCT principles. This study presents a redefinition of the concept of LCSE for sustainable construction and a comprehensive review of available methods and tools to operationalise the LCSE approach in practice, focusing on the consideration of LCT principles in the retrofitting design process, integration of seismic loss estimation and environmental impact assessment, and implementation of integrated retrofitting strategies. The greatest ambition of this work is thus to boost a paradigm shift for building engineers towards an interdisciplinary perspective in building assessment and retrofitting.

Circular Economy in the European Construction Sector: A Review of Strategies for Implementation in Building Renovation

Building renovation was declared a key point for sustainable development, however, the renovation rate of residential buildings in the European Union is insufficient to meet the climate and energy targets set. This paper analyses the main circular economy models used in the construction sector, as well as the situation of the building renovation market, to set a framework for circular economy models in building renovation. Of all the existing strategies in this sector, design, material recovery, building renovation and end-of-life actions would be the best, respectively. It also includes a market analysis consisting of a literature review covering PEST perspectives (political, economic, social and technical) and a SWOT analysis (strengths, weaknesses, opportunities and threats), concluding with a market gap analysis. The results of these analyses allow the development of a series of suggestions and strategies to be followed in order to solve the main barriers that hinder the implementation of the circular economy in the building´s renovation sector.