Plasterboard is a common building material used in several parts of a building. In the case of retrofitting and demolition a part of the waste consists of components combined with the plasterboards, for example, frame work timber.

In the case of new construction and retrofitting, construction waste is produced from clean plasterboard boards, either as cut off pieces or as unused whole boards. This waste can be used as raw material to produce new plasterboards. Manufacturers want to use gypsum from wasted boards to decrease the use of primary gypsum from mining and the quality requirements are relatively easy to achieve.

In this project it has been found that the major construction companies already handle gypsum from new construction separately. This waste fraction could already be used in the production of new boards. Gypsum from retrofitting is usually assembled with other building materials and require more extensive efforts to achieve necessary purity to be used in the productions of new boards. Today, plasterboard waste is deposited or used to improve soil and/or sludge. In order to increase the recycling of plasterboards new inventory routines of rebuilding and demolition projects need to be elaborated. New tools and methods for dismantling plasterboard need to be development to achieve safe working environment and environmentally and economically sustainable recycling.

Preparation plants producing raw material from plasterboard waste are already in operation. Today the waste mainly is wastage from the production stage. In order to increase the recycling of plasterboards from the construction- and demolition branch new logistic systems need to be developed, for example by creating collection points for gypsum board waste and / or developing new transport vehicles and systems. Prerequisites of changing the system of piece work in the construction industry need to be investigated with the intension to create a more sustainable building industry.

Studies investigating microbial diversity in buildings have been performed mainly through the study of dust collected from e. g. floors and door frames and on moisture damaged building materials. A great diversity of mould fungi has been found and the fungus flora is dominated by the genera Aspergillus and Penicillium. The building materials targeted in this specific study were sampled on the back of ceramic tiles from bathroom walls and floors. Furthermore, two different analyses were used to investigate to which degree this specific environment was supportive of microbial growth. Microbial findings were detected in 48 % of the specimens from the spots exposed to liquid water in the bathrooms. To our knowledge, the microbial occurrence in this type of environment has not previously been investigated.. © The Authors.

Microorganisms behind ceramic tiles in bathrooms

In this study the interface between the backside of ceramic tiles and the waterproof membrane was investigated for microbial growth in 13 bathrooms. This interface is made up of the backside of the ceramic tile, tile adhesive and the waterproof membrane. In every day used bathrooms water will accumulate in this particular environment. It is calculated that a tiled wall exposed to water in 15 minutes needs approximately six months to dry out since water is sucked, by capillary actions, through the grout joints between the ceramic tiles. The wall dries through diffusion forces and diffusion force is a weaker than capillary force and therefore the drying need longer time than the wetting of the wall with a water accumulation in the interface as a result.

Samples were taken from areas where the wall and floor had been exposed to free water regularly, due to showering.

Mould and/or bacterial growth was found on 69 % of the analysed specimens from the most water exposed places in the bathrooms. No such growth was found on the samples from the dryer areas. The results shows that although the environment behind the tiles may seem to disadvantaged for microbial growth, due to a limited amount of organic substances and due to pH values not favourable for microbial growth, such growth is possible when the moisture conditions are high.

To our knowledge the microbial occurrence in this particular environment has not been investigated before.

During the last decade, the use of timber (especially massive timber) has increased worldwide, mainly driven by anticipated environmental benefits. However, there is debate on how to handle the susceptibility against microbial growth for wooden constructions, especially during the construction phase. Sometimes full weather protection is used to avoid exposing the wooden material to outdoor conditions, but oftentimes the structures are fully exposed to precipitation. In an earlier study, one construction site using a full weather protection was studied, and the results showed promising results on the improved hygrothermal conditions and reduced risk of mould growth. Moreover, the site contractor also indicated improved work environment and productivity, however, this was not included in that study. This present study aims to investigate the effects of using full weather protection during construction in seven different construction projects to follow-up and broaden the earlier single project study. The studied aspects include the hygrothermal conditions, potential of mould growth, and influence on the work environment. Temperature and relative humidity were measured and analysed. Samples of cross-laminated timber (CLT) were analysed using a microscope, and the results are compared to theoretical mould growth potential. This is measured both inside the weather protection and outside at the seven construction projects. Furthermore, a work environment questionnaire is distributed to workers at the sites to collect the perceived work environment using a full weather protection. The results of the study partly confirm the conclusions from the earlier study, i.e., reducing the risk of mould growth and causing a slightly warmer and dryer conditions than outside. In addition, the results indicate an improved work environment. The majority of the interviewees wishes a weather protection in their next project regarding the work environment.

Preventing mould growth on building materials during construction requires understanding the conditions under which mould can grow. This study conducted an inventory of literature published in the field of moisture, wooden material, and mould growth, selected, documented and categorised relevant literature, and summarised the state of current research. The study is part of a bigger project working to produce a handbook for the moisture-proof production of wooden buildings. The criterium for selecting literature was whether it could provide information on the conditions under which mould growth can occur on wood and wood-based materials during the production stage. This information mainly covers limit values for humidity and temperature, how long these limit values can be exceeded without mould growth, and whether there are differences between different wood materials and between different wood-based products. Both laboratory tests and field studies are included in the material. Most published laboratory studies have been performed under high relative humidity (RH), very favourable to mould growth. Often in these conditions, mould growth begins within one week on all wooden material. Mould growth at lower, less favourable humidity conditions is less studied. However, there are indications that the lowest RH at which mould can grow varies between different qualities of wood. The laboratory studies use different methodologies, and it is not easy to compare results and make general conclusions to achieve the purpose of this study. For example, only discolouring growth is studied, resulting in misleading interpretations, as there may be extensive growth on a material without being visible to the naked eye. Outdoor field studies were evaluated first after several months. The results are difficult to apply to the construction of buildings, as these are not exposed for such long periods without weather protection. Additionally, the field studies only considered the development of discolouring growth. The report also summarises several studies performed at RISE using the same methodology. Some are yet unpublished. More information about the relationship between moisture, temperature, wood material, etc. can be obtained by additional analysis of the results from these studies.

Mould growth on new and used construction timber The growth of mould on building materials varies in both rate and extent from one type of material to another, depending on the nutrients in the material and on the local conditions. In this respect, wood is a sensitive building material. This investigation has compared the growth of mould on new and on used timber under high humidity conditions (90-95 % RH, 22 °C) in a climate test chamber. The used timber was more quickly attacked by mould than was the new timber, regardless of whether it was simply placed in the chamber or was first sterilised and then sprayed with spores before being put into the chamber. However, when the surface of the used timber samples was sawn off, it behaved in the same way as new timber. The results show that old timber cannot simply be incorporated in new structures without a second thought, but that it can work just as well as new timber if the exposed surface of the old timber is first removed.

Pieces of sapwood of pine were buried in soil outdoors for two weeks. Thereafter, the samples were incubated at a high relative humidity for four weeks. The aim of the study was to show the microbiological consequences of soil-contaminated building material being exposed to a prolonged period of high humidity. Microbial activity can be responsible for the production of bad (”mouldy”) odour. Pieces of uncontaminated wood and pieces of wood exposed to sterile soil were used as controls and were incubated in the same way as the soil-contaminated pieces. The results show that pieces which had been in contact with soil generate a bad odour while control samples did not. Chemical analysis (GS-MC) showed that the odorous substance geosmin could be detected only from pieces which generated bad odour. The results lead to the conclusion that it is important to protect wood intended for building purposes from soil contamination. Such a precaution could reduce the risk for bad odour in buildings.

The study contains a field study in which several facades of buildings were studied, as well as a survey where real estate managers have shared their experiences.

On 28% of the total of 268 facades studied in the field study, discoloration was found to such an extent that it was judged to affect the aesthetic impression. Both mould fungi and algae could be identified in the samples taken on discoloured facades. Most of the facade materials studied consisted of rendering or sheet metal. On buildings with façade of sheet metal, the north side was more susceptible to discoloration than other parts of the buildings. No impact on the point of the compass could be observed on buildings with other facade materials. No regional difference in the extent of discoloration could be found in the study. The survey confirms these observations.

The survey shows that many property managers consider that discolouration generally constitutes a problem in their property portfolio, due to costs for maintenance or cleaning, complaints from residents or a reduced general impression of the property portfolio. Although some managers did not consider it to be a general problem, some specific façade types in the property stock may be discoloured and cause problems. Most property managers considered that a façade should not receive an unacceptable discoloration until after at least 10 years. Their experience was that several buildings received such growth already within 10 years after construction of the building.

Respondents of the survey were asked to evaluate discolouration of some example facades, by looking at pictures. It was found that the extent of a discolouration to be regarded as unacceptable varies between different people and different types of buildings. In the survey, real estate owners' experiences of different remediation methods of discoloured facades were surveyed, and it was found that the experiences differ. The property managers believe that a cleaned facade should last at least 5 years before the extent of discoloration becomes unacceptable.

Results from the study will be used as questions and hypotheses in future studies, e.g. to investigate the effectiveness of remediation agents and to develop tools and guidelines for preventing new discoloration.

Trävirke är ett förnyelsebart byggnadsmaterial som kan brytas ner av mikroorganismer. För att en mikrobiell aktivet ska kunna uppstå krävs att rätt miljöbetingelser uppstår och i byggnader är tillgången till vatten den främst reglerande faktorn. I projektet har mögeltillväxten studerats på virke från tre olika småhustillverkare under olika klimatförhållanden och sporexponeringar

Moisture and temperature are the two key environmental parameters that determine the possibility of mould growth on building materials. The time that the material is exposed to these elements is also crucial. The natural environmental conditions of relative humidity and temperature are seldom constant over prolonged time periods in a building. Instead, they vary over time, with fungi encountering both favourable and unfavourable conditions; such variable conditions affect mould growth. This paper reports findings from a laboratory study in which mould growth at alternating RH (between 90% and 60%) or temperature conditions (between 22°C and 5°C) was studied and compared to steady state conditions. Fluctuating RH led to slower mould growth, and when the period of unfavourable/favourable conditions was longer (1 week), growth was affected more than if the duration of these conditions was short (12h). When alternating the temperature weekly between 22°C and 5°C, with a mean of 13°C, the mould growth rate was lower compared to when the temperature was held constant at 22°C.

The aim of the project presented in the report was that construction and demolition waste will be recycled or recycled to a greater extent and at the same time fulfil the quality requirements on the materials.

The purpose of the project has been to map and compile the knowledge and experience of the technical aspects of circular flows of building materials, focusing on quality issues, identifying new projects that can reduce the amount of construction and demolition waste deposited or burned, as well as creating new networks. There is widespread knowledge in the construction industry about these issues and there are also a wide range of research results in different areas. In the project, knowledge and experience have been gathered through literature studies, workshops and seminars, study visits and interviews.

The first part of the report discusses general technical experiences and challenges in different parts of the building chain, while challenges for specific material groups are discussed in the second part of the report. These material groups are polymeric materials, flat glass, stone wool, glass wool, plasterboard, crushed concrete, wood and wood-based materials. The report also presents a survey conducted by Optimera among their professional costumers, which aimed at collecting their experiences and views on sustainable construction.

In general, we can find that there are major challenges in increasing recycling rates for demolition and refurbishment waste. For installation and construction waste, the technical challenges are not as big. Challenges and conditions for increased recycling and reuse with retained good quality vary between different types of materials / products, type of construction project and intended use.

The report proposes a number of proposals in areas where work can be continued. These include improved / expanded inventory for demolition and refurbishment, routines and sampling methods, proper sorting, handling and storage to ensure the right quality, to provide the ability to separate compound materials, logistics, production technology and quality assurance. The results also show the importance of education, networks and meeting places and that research projects are conducted interdisciplinary. There are good opportunities for increased recycling through cooperation throughout the entire building chain.

Discolouration of building facades. A knowledge survey

Microorganisms that grow on facades can cause extensive discoloration, which often poses a problem for home owners as it can provide an aesthetically unfavourable impression of the building. Fouling occurs as a result of a complex process that involves several parameters, including biological factors, climatic factors and factors related to the building. This report describes and discusses these factors and their implications for the incidence of fouling, based on scientifically published research. One chapter of the report deals with cleaning and maintenance of facades. Based on the knowledge available in the literature suggestions are given for further research that can contribute to decreased problems with discoloured facades. Finally, the report provides references to a number of scientific articles categorized by keywords in order to make it easier for those who want to read more on the topic.

The critical moisture level (RHcrit) for mould growth, that is the lowest relative humidity (RH) at which mould can grow, varies between different materials. The factors that most affect mould growth, RH and temperature, also vary in different parts of a building. One way of preventing the growth of mould in buildings is therefore to choose building materials that can withstand the expected conditions, materials that have a higher critical moisture level than the highest expected RH. It is thus crucial that data are available to allow the correct choice of materials to be made. In this paper an innovative laboratory test method for determining the RHcrit of a material is described and discussed. The results from testing of a material according to the method gives information to make the correct choices. The method is developed based on the results of a variety of laboratory studies and has been validated by field studies.

The susceptibility of building materials to mould growth varies. Some are tolerant to high relative humidity in the ambient air without mould growth occurring, while others are less tolerant, and mould can grow in relative humidity as low as 75%. Within a building, constructions are exposed to different temperatures and relative humidities. To minimise the risk of microbial growth, building materials should be chosen that are tolerant to the expected conditions. In this study, the critical moisture levels for ten building materials with a range of expected critical moisture levels (wood-based materials, gypsum boards and inorganic boards) were evaluated. Samples of the building materials were inoculated with spores from six species of mould fungi (Eurotium herbariorum, Aspergillus versicolor, Penicillium chrysogenum, Aureobasidium pullulans, Cladosporium sphaerospermum, Stachybotrys chartarum) and incubated in test cabinets at specified temperature (10 °C and 22 °C) and relative humidity conditions (75-95%); growth of mould was analysed weekly for at least 12 weeks. One of the conclusions is that two similar building materials or products may have considerably different resistance to mould growth, and so the results from one type of building material cannot be applied to the other. Also, in order to compare results from different tests, it is important to use the same test method. It is also important to state the temperature at which the critical moisture level applies and how long the material is exposed to the temperature and relative humidity conditions during the test.

Since 1994 there are restrictions in Sweden on the use of chromium and arsenic containing wood preservatives. These preservatives are now in principle allowed for use in ground contact and water only. The use of chromium and arsenic free preservatives has increased and dominates the Swedish market for commodities above ground (Nordic wood preservation class AB). As the knowledge of the performance of these preservatives is limited, a field trial was set up in order to get more information about the durability in ground and above ground, discolouration by staining fungi, leaching, weathering and corrosion on fasteners in contact with the treated wood. Samples were treated according to class AB in commercial treating plants with the following preservatives: Basilit Bauholz KVD, Impralit KDS, Kemwood ACQ 1900, Tanalith E, Wolmanit CX-S and Wolmanit CX-8. Untreated spruce and heartwood of pine and larch were also included in the trial. In addition to testing according to EN 252 and ENV 12037 (lap-joint), both somewhat modified, testing was also carried out according to methods specially designed for this trial. After five years exposure the results show that: · No treated samples exposed above ground have yet been attacked and very few untreated samples only have been severely attacked by wood destroying fungi. There is thus some concern that the methods used, and in particular the lap-joint method, are not suitable for above ground testing in temperate climates. · The tests in ground indicate that with increasing copper content in the treated wood the better is the performance. · Heartwood of larch performs better than heartwood of pine in the in ground tests. On contrary, heartwood of pine shows better decay resistance than heartwood of larch in the above ground tests. · All samples are more or less attacked by bluestain fungi. Untreated samples are severely attacked. · Stainless steel has the best performance against corrosion. Wood treated with Kemwood ACQ 1900 and Wolmanit CX-8 seems to accelerate the corrosion of most other fastener materials. · The leaching of the chromium and arsenic free preservatives seems to be substantial whereas the leaching from CCA-treated references is little or moderate. For wood preservatives containing copper and an organic active ingredient, copper seems to be less susceptible to leaching then the organic component for which not only leaching but also chemical decomposition may take place.

The susceptibility for mould growth varies among different building materials. One way to describe the susceptibility is the lowest RH at which mould can grow on a specific material, the critical moisture level (RHcrit). Determining RHcrit for materials provide the basis for material choice in designs where moisture and temperature conditions are known. In this study, RHcrit of 21different products were determined according to SIS-TS 41:2014/SPMet 4927. This test method is developed based on the results of a variety of laboratory studies and validated by field studies. Test specimens were inoculated with a suspension containing spores from six different mould fungi and were then incubated in moisture chambers at four levels of RH at 22 °C. After 12 weeks specimens were analysed for mould growth. RHcrit was determined based on the lowest RH at which mould grew on the specimens. RHcrit varied among different products, even between product belonging to a similar group of material, for example, calcium silicate boards or gypsum boards. The results show, and confirm, previous findings that it is not possible to estimate RHcrit for a specific product based on material group. Instead, each product must be tested. © The Authors

Mould growth results from a complex interaction between environmental factors, material properties, and mould fungi characteristics. These interactions must be considered during the design, construction and maintenance of a building to prevent growth. Mould prediction models aim to predict whether mould will grow on a specific material in a part of building with a known, or simulated, relative humidity and temperature. They are often used in the design phase. Several models are available. There is limited research on the performance of the models in real buildings. This study aimed to evaluate six different models, using data from five building parts. The predictions on whether mould growth was expected or not were compared to actual mould growth observations on five building materials. The study was performed as a round-robin. Most models underestimated the possibility for mould when humidity and temperature varied a lot by time. The outcome also depended on the end-user, who needs to make assumptions and parameter values choices on, for example, material susceptibility for mould growth. Therefore, using the same climate data, mould growth prediction may differ depending on who makes the prediction. One model, MOGLI model, where input data comes from laboratory tests and no such assumptions must be made, predicted correct in most cases. One conclusion of the study is that when predictions are made in practice, the results must be used cautiously. More knowledge is needed to understand, and more accurately model, the relationships between the moisture and temperature variations in buildings and the risk for mould growth. 

Building materials differ in their susceptibility to mould growth. Wood is a material often considered to have a low mould resistance. However, wood is not a homogenous material and different characteristics of the material are expected to have an impact on mould growth. In this paper, it was shown that wood species (pine or spruce), sawing pattern (centre-board or side-board) and surface structure (planed or sawn) affected mould growth. In addition, it was indicated that the susceptibility cannot be described by one single parameter, but also depends on other parameters. It is therefore difficult to estimate the susceptibility of wood in general. These conclusions were drawn from a meta-analysis, using data from five separate, previously performed laboratory studies conducted at 90% relative humidity and 22 °C, and from a laboratory study performed at 95% RH and 22 °C. © 2016 Springer-Verlag Berlin Heidelberg

This study assessed the environmental impacts of recycling the plant nutrients in anaerobically digested food waste as fertilizer in agriculture. This was compared with the impacts of using chemical fertilizer, where the food waste was incinerated, producing heat. The study site was a biogas plant in central Sweden and life cycle assessment methodology was used. The impacts studied were primary energy use, global warming potential (GWP), potential acidification, potential eutrophication, cadmium flow to farmland and use of phosphate rock. Use of digested food waste as fertilizer proved to have larger negative results than use of chemical fertilizer in all categories assessed except use of non-renewable phosphate rock. Sensitivity analyses showed that the scenarios were comparable in terms of primary energy use and better for GWP if some improvements in the anaerobic digestion system were made. However, acidification and eutrophication caused by digestate handling and the cadmium content of digestate should still be considered.

Mould growth in buildings is a complex process, affected by moisture and temperature, the properties of the building material as well as characteristics of the mould fungi. The complexity poses challenges when assessing the risk of mould growth in buildings. Mathematical models are often used to predict whether mould will grow in a part of building with expected RH and temperature conditions. The models can be described as static or dynamic. In a previous round-robin study, comparing results from models with observations from field studies, the outcome of the dynamic models evaluated depended on the user of the model. Also, the models often underestimated the risk of mould growth. A better agreement was found for static models, especially for the PJ-model. It is a part of a standardised technical specification (SIS-TS 41:2014) and has not previously been described as a model. The critical moisture level (RHcrit), determined by tests according to the method, is used as input. Thus, the subjectivity in the predictions is reduced. RHcrit is the lowest moisture level at which mould can grow and is temperature-dependent. The PJ-model provides an equation to estimate RHcrit at typical temperatures in buildings. If RH in a building section exceeds the limit values at the current temperature, growth is predicted. This paper describes the PJ-model version 1.0, some of the extensive work performed during the development and validation of the model and the ongoing work to refine the model to include considering transient conditions and measurement uncertainties. © The Authors

Materials that are stored or used in damp conditions may be subject to mould growth. However, all materials are not equally susceptible; for each specific material, there is a critical moisture level for mould growth. If this is exceeded, there is a risk that mould fungi will develop on the material. This level can be determined in accelerated laboratory tests, at constant temperatures and relative humidity (RH) favourable to mould growth. Within a building however, these parameters are expected to vary from one part of the construction to another, and are seldom constant; there is fluctuation in temperature and RH due to seasonal or shorter-term variations. In this study, test pieces of the same materials tested in a laboratory environment were placed in three outdoor ventilated crawl spaces and three outdoor ventilated attics, where the temperature and RH varied, and mould growth on the test pieces was studied over 2.5 years. Material-specific mould growth curves were produced based on critical moisture levels, as determined in laboratory experiments under constant temperature and RH. When the actual conditions of RH and temperature exceeded these curves, there was mould growth on the test pieces if the time was sufficiently long. The conclusion from the study is that although conditions in laboratory studies are simplified and accelerated, the results serve well to indicate mould growth within a building construction.

In this project we have tested a mould model originally developed by Skanska (the m-model) and a method developed by RISE in Sweden (the GLC-method) on data from both laboratory and field measurements. The laboratory measurements had durations of a few months and were made in climate chambers at RISE; the field measurements were made in 12 buildings during 30 months. In both cases, temperature, relative humidity and mould growth was assessed on six different materials. The results were used to investigate if the m-model or the GLC-method could predict when there was mould growth. Both methods could differentiate between the (dry) cases without mould and the (moist) cases with mould. However, we could not find mould resistance parameters for the tested materials to be used with the m-model. This could be because the m-model cannot predict mould growth well enough, but it can also be because the types of measurements that we have made have relative large uncertainties in relative humidity. Isotheral calorimetry was also investigated as an interesting method to study how drying affects the activity of mould fungi.

The problem with discoloration, due to fungal growth, of wooden outdoor constructions seems to have increased in recent years. One reason for this increase might be an impact of new drying methods of timber. Modern kiln drying methods use high temperatures in an effort to shorten the drying process, which leads to fast capillary water transport and subsequently redistribution and accumulation of dissolved substances at the surface. These can then be used as nutrients by fungi. In this study, wood was dried according to different simulated drying schedules. The mould resistance of the timber was then tested. Wood dried at room temperature was used as a reference. No differences could be confirmed at the end of the test; mould growth was extensive on all the samples. However, mould growth started earlier on the kiln-dried samples than on air-dried timber. As for the discolouring fungus, there was a clear difference between wood dried at room temperature and kiln-dried wood, though no difference could be established between the two artificial methods.

The susceptibility of building materials to mould growth varies. Some are tolerant to high relative humidity in the ambient air without mould growth occurring, while others are less tolerant, and mould can grow in relative humidity as low as 75%. Within a building, constructions are exposed to different temperatures and relative humidities. To minimise the risk of microbial growth, building materials should be chosen that are tolerant to the expected conditions. In this study, the critical moisture levels for ten building materials with a range of expected critical moisture levels (wood-based materials, gypsum boards and inorganic boards) were evaluated. Samples of the building materials were inoculated with spores from six species of mould fungi (Eurotium herbariorum, Aspergillus versicolor, Penicillium chrysogenum, Aureobasidium pullulans, Cladosporium sphaerospermum, Stachybotrys chartarum) and incubated in test cabinets at specified temperature (10 _x0001_C and 22 _x0001_C) and relative humidity conditions (75e95%); growth of mould was analysed weekly for at least 12 weeks. One of the conclusions is that two similar building materials or products may have considerably different resistance to mould growth, and so the results from one type of building material cannot be applied to the other. Also, in order to compare results from different tests, it is important to use the same test method. It is also important to state the temperature at which the critical moisture level applies and how long the material is exposed to the temperature and relative humidity conditions during the test.

A circular economy (CE) represents the key alternative to the linear ‘take-make-consume-dispose’ economic model, that still predominates in the construction sector. This study investigates how policies support CE-focused businesses in the construction sector in the Nordics. A literature review, the creation of a database, a review of Nordic actors with a CE focus, and targeted interviews with actors across the value chain of the construction sector in Denmark, Finland, Norway, and Sweden enabled us to benchmark the CE policy landscape and assess how CE policies at different levels support CE business models in the construction sector. The results show that the construction sector is well represented in the CE policy frameworks and that many business opportunities are created when national and local policies are put into practice. The implementation of policies is mainly done via three key concepts, i.e., planning, requirements for sustainable constructions, and requirements for public procurement. It can be concluded that policies are drivers for the implementation of a CE and support CE business models in the Nordics. © 2021 by the authors.