Assistant professor at the Department of Indoor Environmental and Building Services Engineering at the Faculty of Civil Engineering at Czech Technical University in Prague, Czechia firstname.lastname@example.org (corresponding author)
Full-time professor at the Department of Indoor Environmental and Building Services Engineering at the Faculty of Civil Engineering at Czech Technical University in Prague, Czechia email@example.com
Researcher with the Technological University of the Shannon, Ireland Martin.Breen@tus.ie
Educational technologist in ISSO - the Dutch Knowledge Centre for the building and building services sector. Netherlands firstname.lastname@example.org
The construction industry, notorious for waste and emissions, is shifting gears towards a circular economy. Even the new EPBD recast proposal emphasises the circular economy as a necessary approach. Explore BUS-GoCircular project, redefining construction practices. Discover how this initiative, driven by a groundbreaking qualification framework, revolutionizes skills and resources to reshape the industry’s sustainable future.
Keywords: Circular economy, Construction industry, Sustainability, Qualification framework, EPBD recast proposal, Circular construction skills, Training programs
The circular economy is an approach that is an essential part of sustainable development. It is obvious that the current linear approach (take-make-waste) is in direct conflict with sustainability . In the current economy, we take materials from the earth, make products from them, and eventually throw them away as waste - the process is linear. In a circular economy, on the other hand, waste ceases to be generated . The circular economy aims to maintain the value of products, materials and resources for as long as possible in the economic cycle and return them to the production cycle at the end of their life, while minimising waste generation .
The circular economy has the potential to tackle climate change and other global issues such as biodiversity loss, waste and pollution by decoupling economic activity from the consumption of scarce resources.
The circular economy is based on three principles:
· Eliminate waste and pollution
· To ensure the circulation of products and materials (with their highest value)
· To regenerate nature
By supporting the transition to renewable energy and materials, the circular economy is a resilient system that benefits business, people and the environment .
CIRCULAR ECONOMY IN THE CONSTRUCTION INDUSTRY
The construction sector consumes almost half of the world's extracted materials annually and contributes significantly to greenhouse gas emissions.
During their lifetime of operation, buildings are responsible for 40% of EU final energy consumption, and 36% of greenhouse gas emissions. The embodied emissions from the rest of the building life cycle are estimated to contribute at least a further 10% . More than 50% of all extracted materials  are attributed to buildings, while construction is responsible  for around 2.3 billion tonnes of waste generated per year in the EU, or 36% of the total .
The way we design, build, and ultimately demolish is rooted in a linear "take-make-waste" economy. By applying circular economy principles to the design of buildings, infrastructure and other elements, we can reduce greenhouse gas emissions while creating urban areas that are more liveable, productive and comfortable. The circular economy has the potential to reduce global CO₂ emissions from building materials by reducing demand for steel, aluminium, cement and plastic. It could also make the sector more resilient to supply shortages and fluctuations in raw material prices.
By using new technologies and innovative business models, we can increase the value of our buildings if we rethink the way we design them. This will keep resources and building materials economical and prevent them from becoming waste.
Policy makers at all levels of government, investors and construction clients (developers, infrastructure operators and building owners) are key players in the transition of the construction sector to a circular economy. Policymakers can use policy levers such as public procurement to stimulate demand for circular solutions and facilitate the emergence of public-private partnerships. Investors can engage in public-private partnerships to develop circular projects, encouraging research into new techniques that eliminate structural waste and preserve or enhance value. Clients in the building industry can support public-private partnerships to develop circular projects and develop a fact base demonstrating the value of the circular economy in the built environment .
The circular economy is one of the recognised principles for ensuring a sustainable future and the question is how to bring it into the construction sector in the most effective way. A problem that may slow down or limit the successful application of this principle is the lack of a skilled workforce across all levels and professions in this sector. This issue is addressed in the European H2020 project BUS-GoCircular. The aim of the project was to map the situation in the European construction industry in terms of circular skills, to develop a task-based qualification framework and to produce learning materials that would be freely available to the general public.
CIRCULAR CONSTRUCTION SKILLS QUALIFICATION FRAMEWORK
Task-based qualification framework of circular construction skills is built on the idea of key elements of circular economy that defines most of the concepts associated with the circular economy.
Key elements of circular economy
According to , 8 key elements need to be addressed for a successful application of the circular economy. The following three are the most basic and supporting elements:
I. Prioritizing renewable resources: striving to ensure the efficient use of renewable, reusable and non-toxic sources of materials and energy.
II. Preserving and extending what is already produced: While resources are in use, they are maintained, repaired and upgraded to maximise their lifetime and, where appropriate, give them a second life through take-back strategies.
III. Resource recovery: Using waste streams as a source of secondary raw materials and for re-use and recycling.
In addition to the three basic elements, five supporting elements can be defined:
i. Design for the future: the design needs to take a system perspective, use the right materials, design for durability and design for long-term future use.
ii. Collaboration to create shared value: Collaboration across the supply chain, internally with-in organisations and with the public sector to increase transparency and create shared value.
iii. Rethinking the business model: Consider opportunities to create more value and align incen-tives that build on the interaction between products and services.
iv. Incorporate digital technologies: Enable to monitor and optimise resource use and strength-en links between supply chain actors through digital, online platforms and technologies that provide information.
v. Strengthening and developing knowledge: Developing research, structuring knowledge, fos-tering innovation networks and disseminating results fairly are essential.
The supporting elements support the application of circular economy by removing some of the barriers to the basic elements - for example, the use of waste as a resource is difficult to implement if products have not been designed with possible recycling in mind - so design for the future is a supporting element. Product life extension can be enabled through new business models such as rental and resale .
Figure 1. The key elements of the circular economy. 
Built environment value chain
Task-based qualification framework also takes into account that in the built environment value chain where there are different roles within the different stages of the building. Based on  following stages are considered:
1. Plan: design and commission (new and existing buildings);
2. Procure / source: materials, products and services (new and existing buildings);
3. Construct: build and fit-out (new buildings);
4. Operate: maintain, renovate and manage (existing buildings);
5. End of service life (EoSL): Deconstruct, dismantle, repurpose, sort and process
6. Governance: ambition setting through policy and standards, and compliance
The sixth point doesn’t represent stage, but greatly influences attitudes to building projects.
Table 1. Example of key core element, its applications to circular construction and affected professions in different stages according to .
Core key element
Approach to circular construction
Prioritise regenerative resources
Use grey water for certain applications (e.g. washing)
Use Plant-Based Biofilters to Purify Household Wastewater
Sustainable water technology
Collect and reuse water in humid interior areas, e.g. cellars
Cascading of water
architect, designer, plumber, electrical installer and technician
procurement officer, project developer
plumber, electrical installer and technician, roofer, gardener (roof and façade), interior planter, arboriculturalist horticulturist
building management, plumber, gardener (roof and façade), interior planter, arboriculturalist horticulturist
demolition/ deconstruction labourer, site analyst, deconstruction auditor, urban miner
BUS-GoCircular Qualification framework
The qualification framework for the application of circular economy principles consists of 9 main tasks and each task is further divided into 8-10 sub-tasks. For each sub-task, the profession that can implement the principle in its activities is also indicated (e.g. architect, civil engineer, plumber, roofer) by its abbreviation (e.g. AR, CE, P, R). For each sub-task, 'Units of Learning Outcomes' (ULOs) are further defined, where each unit is described by competence, skills and knowledge. Information on which professionals are needed for each subtask is added. By linking the sub-tasks to the corresponding professions, it can be decided which learning objectives the members of the profession should have and therefore which learning outcomes should be obtained.
Figure 2. Example of Task 1 and its subtasks, including corresponding ULO numbers and relevant professions from the Qualification Framework. 
The Qualification Framework is one of the significant outputs of the project in its comprehensiveness and scope and is freely available on the project website. In addition to providing an orientation on the issues, it can help to define the necessary competences/knowledge for almost any area of the construction industry, and thus tell in which direction to focus further training of relevant professions.
Figure 3. Example of Unit of Learning Outcomes, consisting of competences, skills, and knowledge components from the Qualification Framework. 
At the same time, the project mapped and analysed the current level of knowledge of circular economy principles among construction workers. To this end, an extensive questionnaire survey was carried out in seven European countries. The questionnaire was based on the areas of the qualification framework and looked at the level of knowledge the respondent feels he/she has in the area and also what the level of knowledge should be for the successful application of circular economy principles in his/her profession. The results of the survey were further discussed and corrected in each country with the help of external advisory boards composed of experts working in the construction sector. The survey shows that there are differences between countries and therefore there is a great potential for the development of training programmes for the whole construction sector within Europe.
OUTPUTS OF THE BUS-GOCIRCULAR PROJECT
Eleven learning modules for trainers
Based on the results of a survey of current and necessary skills and the structure of the qualification framework, the project developed a bank of freely available materials for the development of training programmes. In order to better navigate the available materials, 11 learning modules were created covering 52 skills and 38 occupations in the construction industry.
Training material for public procurers
Another training material aims to help public procurers and policymakers better understand how they can stimulate demand for circular construction skills through public procurement. It is in the form of a presentation and can be used as a self-study tool with links to other resources to learn more about the topic.
BUILD UP Skills Advisor app
Learning outcomes from the framework will also be added to the BUILD UP Skills Advisor app, to further increase skills recognition for professionals and craftsmen. The BUILD UP Skills Advisor app is a free tool for practitioners and craftsmen to look for opportunities for trainings in Europe and some specific EU countries. It also contains a community-managed content repository and can facilitate the use of micro-credentials for personal recognition and lifelong learning.
Training plans and training packages for SMEs
Other outputs of the project are training packages for SMEs. These packages consist of attractive training materials, including different formats, and will be freely available after the project to all organisations wishing to upskill their employees in the circular economy. Four different training plans were drawn up depending on the target groups of different SMEs (Table 2).
Table 2. Designed Training plans overview with target SMEs.
TRAINING PLAN (TP)
CONSTRUCTION WORKS IN CIRCULARITY
Company specialised in specific material systems – installers
Carpenter (wood) company
Another specific profession (welder, plasterer, plumbers) company
CIRCULARITY IN INSTALLATIONS
Electrical installation company
Water systems installation company
HVAC installation company
RE installations company
Sustainable consulting or engineering, architecture´s office
Demolition company (or building companies)
Waste management company
Waste treatment and recycling company
Each training plan consists of several modules, where the topics, format and possible timing is designed. These materials will be available in English and some of them also in 6 more European languages of the project partners (Spanish, Dutch, Czech, Bulgarian, Hungarian and Croatian). Examples of the designed parts of the training plans can be seen in Figure 4 and Figure 5.
Figure 4. Example of part of the “Initial Circularity” Training plan.
Figure 5. Example of part of the “Circularity in Installations” Training plan.
Train the Trainers program
The project also provided a train the trainer programme for people from a wide range of professions working in the education sector. The first training of trainers took place in January 2023 in Prague and was a face-to-face event. Further trainings took place online in June and November 2023. During the course, participants were introduced to the project outputs to date, all available materials and teaching methods. The course also has its interactive part, where future training programmes were created in groups divided by professions. During these three courses, a total of 57 trainers of various professions from 16 countries were trained, who can further disseminate the idea of the circular economy in the construction industry in the form of training targeted at various groups of professionals.
According to the current state of knowledge, the circular economy is one of the strategies leading to a sustainable construction industry. Greater application of circular economy means that less waste will be produced, making it easier to greater reuse and recycling of products and materials at the end of their useful life; and helping to reduce environmental impacts and life cycle costs. However, a properly trained workforce across the construction sector is essential for its implementation.
The results of the BUS-GoCircular project can be found at: https://busgocircular.eu/.
This paper is based on the results of the project BUS-GoCircular, which has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No. 101033740. The contents of this paper reflect only the author’s view and the Agency and the Commission are not responsible for any use that may be made of the information it contains.
 Circular Economy & SDGs, How circular economy practices help to achieve the Sustainable Development Goals: https://circulareconomy.europa.eu/platform/sites/default/files/3228_brochure_sdg_-_hch_cmyk_a4_portrait_-_0520-012.pdf.
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 IEA, 2019. Material Efficiency in Clean Energy Transitions reports estimates that 10-20% of EU buildings’ CO2 footprint represents the embodied carbon.
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