6. Circular construction projects, support platforms and tools

This section provides examples of circular construction tools, platforms, and construction projects in the Nordic countries.

The buildings division of the City of Copenhagen has developed a handbook for a Circular Economy (Håndbog i cirkulær økonomi), which contains a description of circular services in construction, a sustainable price pyramid, a catalogue of material-specific circular demands that can be implemented in the process of commissioning construction, and inspirational examples of circular construction. The material-specific circular demands cover concrete, plaster, bricks, wood, glass, mineral wool insulation, and steel, as well as aspects like how to reintegrate recovered materials, sorting demands, certification, and use scenarios. There are also demands concerning resource mapping before demolition and proper source separation of waste fractions during demolition.

The handbook is operational and designed to help the City of Copenhagen integrate a circular economy into their construction activities. It is inserted as an annex in consultancy contracts, and there are passages used selectively as necessary and relevant within contracts with building companies.

The 2023 version of the handbook can be found here: https://byk.kk.dk/sites/default/files/2022-12/H%C3%A5ndbog.pdf

The Circular Builders project developed, tested, and revised circular solutions in construction in thirteen specific case studies across nine municipalities in Sweden and Denmark. The project took a primarily practical approach by focusing directly on construction projects in the respective municipalities. This led to solutions and lessons that reflect real-life problems when facing attempts to integrate circular construction in the Nordic countries.

The main lessons learned from the project fell into three categories: (a) integrating circular construction into plans, strategies, and internal processes forms the core driver within the individual cases, (b) the resulting efforts and initiatives to drive circularity in the actual construction and demolition processes, and (c) how these processes interface within the wider construction sector through market dialogue and ensure local anchoring of circular construction projects. More specifically, the key lessons are: try to reuse first, since a lot can actually be achieved within existing budgets, demonstration projects are an effective way to anchor circular construction, a new understanding of risk and risk sharing is required (and is developed), and the market is ready to start moving, but it’s not at full speed yet—new knowledge and experience is needed across the board (Gate21, u.d.).

Stakeholders in the Danish construction industry have been working since 2016 to develop a way to address the data challenge related to mapping and communica­ting information on the content of construction materials, which can also challenge the reusability of products. This work has produced the “Digital Material Pass­port” (Materialepas, u.d.). The Digital Material Passport collects the data on construction products. This is a prerequisite for the actors in the construction industry in order to make informed and well-founded decisions. Today, it is unthink­able to buy food without a product declaration. Unfortunately, this is not the case when it comes to the building materials that form our technical environment.

The material passport declares important information about a product; for example, it provides information about ingredients, the chemical processes used in production, and its ability to be part of circular or sustainable construction and future resource flows.

BusinessReuse is a Grand Solutions project that aims to overcome the uncertainty of reusing load-bearing or other structural elements in new buildings by developing a system to classify recycled materials. This seeks to measure and document the remaining life span of the recovered materials in such a way that destructive testing of every element for reuse is avoided, as well as document the load bearing strength of the elements. The project is financed by Innovation Fund Denmark and RealDania. It is a broad coalition of actors from the construction sector: Lendager, DTU, DTU Skylab, Danish Standard, Adsbøll Renovering, Gate 21, Rambøll, and the Center for Små og Mellemstore virksomheder Aarhus BSS.

The first part of the project establishes a baseline demand for acceptable risk within the industry, as well as what the documentation demands of that risk and what the physical properties of the building elements are. The second part will develop non-destructive testing methods that can be used to meet these documentation requirements. This should then be scaled up to national technical specifications through the existing standardisation channels, fully integrating and normalising reuse within the construction industry (BusinessReuse, 2021).

CCbuild (The Center for Circular Building) is led by the IVL Swedish Environmental Research Institute and developed with CCbuild’s partners. CCbuild is a collaborative platform started in 2015 with a few partners, and now it has slightly more than 100, which include real estate owners, sector organisations, material manufacturers, etc. (CCBuild, u.d.). They share knowledge and arrange meetings to spread knowledge about circular construction. CCbuild was developed in three steps. In step 1, a few partners discussed and evaluated the following questions: “Why are we not working more circular?”, “Why are we not working with reuse?”, “What are the challenges and solutions?”. In step 2, two pilot reuse projects were established. In step 3, a few services were developed: a Digital inventory app, a material bank, and a marketplace (Lindholm, 2022).

Vasakronan, a real estate company that develops, administers, and owns offices in the biggest cities in Sweden, has been partners with CCbuild since 2015 (CCBuild, u.d.). They are also part of Business Region Gothenburg. Their goal is to include reuse in every project, and the amount of reused material is exponentially growing; this includes doors, kitchenettes, fittings, etc. (Höjer, 2022). In one renovation project of an office in central Gothenburg, they set a goal of 100 per cent reuse without lowering the quality or compromising design or functionality. Having this clear goal helped focus efforts on reuse, and in the end, 91 per cent of the materials or products from the pre-renovation building were reused (Vasakronan, 2020).

Materialbanken was developed as a supporting tool for the redevelopment of the Varvsstaden area of Malmö. Work on the Materialbanken began before demolition, and soil remediation work began with the intention of gaining an overview of the areas resource assets. This included not only information on the materials' type, size, and potential value, but also the embodied CO₂ emissions. It enabled the Varvsstaden organisation to understand and direct materials to correct treatment or preparation processes for their eventual reuse. It has since developed into a vital tool for calculating and communicating the environmental benefits of reusing building materials.

Materialbanken can be searched to identify specific materials as well as find comprehensive information on the environmental effects of reusing and recycling these materials. They are used to present the environmental and economic benefits of recycling and reuse broken down by building and material—even to specific items. While most of the recovered material and building products will be used on the Varvsstaden site, it is anticipated that many of the materials will be used in applications in the local area (Materialbanken, u.d.).

As a response to the need to increase recycling and recovery of C&D waste to meet Waste Framework Directive targets, The Finnish Environmental Protection Agency published three guides in 2019 to support better and more resource-efficient demolition. The guides covered the procurement process, the implementation of the demolition process, and the process for conducting pre-demolition material audits.

The Finnish pre-demolition audit is based on the EU-initiated audit procedure. The Guide provides a step-by-step walkthrough of pre-demolition audits. It explains the stages of conducting a pre-demolition audit, how to understand the materials, their anticipated application and their potentials for recovery, the process steps involved in field research and site visits, how the results should be reported and communicated, and what should appear in the materials inventory.

This provides practitioners and procurers with a solid knowledge base with which to design and conduct pre-demolition audits and gain useful results that can lead to the better reuse and recycling of materials in buildings scheduled for demolition (Valtioneuvosto, 2019).

Pikku-Finlandia was designed as a temporary replacement events facility during the three-year renovation of the landmark Finlandia Hall. The project was organised by Aalto University, the City of Helsinki, and Finlandia Hall in the autumn of 2019. It began with a graduate-level joint design studio at the Aalto University Department of Architecture, which resulted in a design proposal by student Jaakko Torvinen called Finlandia-forest, inspired by a Finnish boreal forest. The design used whole untrimmed tree trunks as load-bearing columns, thus minimising processing costs and impacts. The 2000 m² Pikku-Finlandia has four multifunctional halls, a gallery, and a cafe. Three of the multifunctional halls can be combined into one large area together with the lobby. This flexibility allows the building to fulfil a variety of functions and meet a variety of needs. Following the renovation, the building will be disassembled and moved to a new location and continue its life serving another function, such as a school or day-care centre for example, for at least the next 50 years. In this way, this circular, low-impact building not only uses natural, non-hazardous recyclable materials, but can also be moved, reused, and adapted as needed (Jaakkotorvinen, 2022).

Varvsstaden is an old industrial area in Malmö covering 180,000 m² between the city centre and the West Harbour. The area is undergoing redevelopment to provide extra capacity to the city. Circular construction is a key principle for the development, so the buildings already on the site are seen as material assets rather than waste challenges. The buildings were constructed in the second half of the 19^th century or the beginning of the 20^th century, and as such many have cultural value and contain high quality materials. The goal is to maintain the integrity of as many of the old factory buildings as possible (Varvsstaden, u.d.). The buildings that cannot be kept are carefully dismantled and the material is reused in the same area. Bricks, glass, wood, concrete, and steel are circulated from the old buildings to new constructions and installations either within Varvsstaden or in other nearby projects (Materialbanken, u.d.).

Offices, residences, and schools are being built in the area. Since buildings are deconstructed, there is an opportunity for reuse, and Varvsstaden can carry out the activities in the reuse process themselves: deconstruction, material storage, documentation, upcycling of material, and construction. Apart from the positive environmental effects from reuse, there is also an economic gain, and the value of the old buildings remains intact. A key tool used in facilitating the reuse of materials from Varvsstaden is Materialbanken (Materialbanken, u.d.), an online catalogue of materials in the existing buildings on site (Wennerholm, 2022).

In Svartlamon in Trøndelag, Norway, a test house was built primarily out of reused building materials. The study intended to increase understanding of the potential of reusing materials in new buildings. The experiment was the basis for understanding the interaction between people and materials in relation to the environment. Using recycled materials and products can be justified as a conscious choice of materials. Resource consciousness is integrated into the design as well as into social and ecological sustainability in the development of architecture.

The project had special prerequisites that simplified the building, such as not having to modify the façade. The project gained permission to build without complying with some general building regulations, which otherwise would have made it more challenging. For example, the project was not adapted for accessibility, nor did it meet insulation requirements.

A conclusion made after the investigation was that building with recycled products is not necessarily easier than with conventional materials since it is more time consuming when processes such as material inventory and cleansing need to be done. However, it does indeed give a more personal and unique look. When building with recycled products, it is important to be innovative and creative with the products and their functions, such as reusing a door as an indoor wall façade.

Building products such as doors, windows, moldings, and floorboards were examples of products with high reuse potential.

By using recycled materials, climate footprints can be lowered. But apart from being environmentally friendly, the building retains its cultural value since the components can continue to recount its history (Lundmark, 2019).

Kristian Augusts gate 23 (KA 23), built in 1950 in Oslo, Norway, was originally the headquarters of the Norwegian employer’s association. The office building was bought by Höegh Eiendom in 2019. The building’s façades are protected pursuant to the Planning and Building Act. Höegh Eiendom has renovated the building in line with FutureBuilt’s criteria for circular buildings, and 50 per cent of the materials and building components are reused or reusable. The façades have been retained along with the load-bearing system, covers, stairwell, footing, and foundations, in addition to as many of the interior walls as possible. Details and materials such as the dark wood panels, terrazzo floors, and scagliola walls and roof have been retained, as well as several building components and interiors. The inclusion of new building parts has been conditioned on their reusability, in line with circular principles.

A greenhouse gas inventory was conducted in line with FutureBuilt’s criteria to ensure that total emissions were reduced by at least 50 per cent. The inventory was used actively during planning to keep emissions in check (FutureBuilt, 2023).

Brákarborg Kindergarten was awarded the Icelandic Green Buildings Council’s Green Shovel award in 2022 and was certified very good under the BREEAM certification scheme. The project consisted of renovating an existing commercial property at Kleppsvegi 150-152. A concerted effort was made to reuse the existing concrete structure, which eased the construction process and minimised the production and transport of virgin building materials. This was verified in the design process by undertaking a comparative renovation vs new build LCA on the site. The design phase also included detailed waste reports that estimated the amount of waste by category, along with a plan for treatment of that waste. Many of the installations of the commercial property were recovered for reuse by the architect, Arkís, in the construction and design of their new offices in Kópavogur. This included toilet bowls, sinks and faucets, door pumps, and curtains. As the site was going to be replanted with new vegetation, the existing vegetation was carefully removed and replanted elsewhere in Reykjavik, while the new building owners, the City of Reykjavík, reused various electrical and computer equipment from the site in other projects (Grænni byggð, 2022) (Grænni byggð, u.d.) (Grænni byggð, 2021).

In Gufunes in the northeast of Reykjavik, old industrial buildings have been renovated and turned into apartments, workshops, and studios for artists. The buildings have been renovated by reusing building materials that have been collected and stored at the construction site. Inga Lóa Guðjónsdóttir and Hilmar Páll Jóhannesson are responsible for the project, which goes by the name of Loftkastalinn. The surrounding area will become a diverse settlement of entrepreneurs and creative industries, including a “film village” that will become the centre of Icelandic film production. Inga Lóa and Hilmar have collected a large amount of used building materials and interior items that have been reused in the renovation of the buildings. This project illustrates that reuse can be a viable solution for used construction materials as long as the commitment is strong.

In most instances, little time is spent removing reusable materials from buildings that need to be demolished, so when Seljavegur 2, a building in the west of Reykjavik, was demolished, Loftkastallin had the opportunity to remove material that could be reused. Examples of materials removed include stone wool (500 m²), dense wool (300 m²), electrical panels, electrical cables, fire systems, fire hoses, plugs and switches, suspended toilets and sinks, bathroom fixtures, industrial doors, fire doors, sound doors, exterior doors, furnaces, timber, etc. Loftkastalinn has also received materials from other demolition or refurbishment projects, including steel beams, parquet flooring, and a steel spiral staircase. Loftkastalinn will also uses visually defective sandwich panels for various purposes (Grænni byggð, Mannvirkjastofnun, 2019).