Aarhus University Seal / Aarhus Universitets segl

No. 220: Source separation of household waste in apartment buildings

Petersen, L.K. & Kristiansen, T.N.B. 2017. Kildesortering i etageejendomme. Husholdninger og affaldsansvarlige. Aarhus Universitet, DCE – Nationalt Center for Miljø og Energi, 68 s. - Videnskabelig rapport fra DCE - Nationalt Center for Miljø og Energi nr. 220. http://dce2.au.dk/pub/SR220.pdf



Does it make sense to ask private households to separate their waste in different fractions? That is the basic question in this report which presents findings from a research project regarding source separation of household waste in apartment buildings. The project focused mainly on the norms and practices of householders and the role of intermediaries such as caretakers or janitors who maintain apartment buildings.

The topic of source separation is important because household waste contains valuable resources which can be recycled, thereby contributing to a more circular economy. And the development of circular economy has both nationally and internationally been defined as one of the most important challenges of our time.

Increased recycling does, however, require careful management of the entire waste stream from generation of waste in households and businesses to regeneration of waste into new materials and products. Source separation is an important element in this careful management, and in order to have well-functioning waste separation it is necessary to understand the perceptions and practices of householders perceive. This report presents new findings regarding the norms that exist among householders regarding waste handling and how these norms are enacted in practice.

The project focused on apartment buildings because apartments constitute 40 % of all accommodation in Denmark and 92 % of all accommodation in the municipalities of Copenhagen and Frederiksberg, and because there are special conditions for waste handling in that part of the housing stock. Waste is typically collected in garbage sheds, in basements at the end of garbage chutes or at other stands in the communal areas within the estate and often handled by intermediaries, i.e. caretakers and janitors, before it is fetched by garbage collectors. This report contributes new knowledge about the role of these intermediaries.

The project’s empirical investigations were conducted in the fall of 2015 and consisted of the following.

  • Interviews with intermediaries in the waste stream in apartment building, paid caretakers as well as unpaid persons in charge of waste hand­ling (typically members of resident boards).
  • Interviews with residents in apartment buildings representing different age groups, neighbourhoods, apartment sizes etc.
  • A questionnaire study distributed to board members in cooperatively owned apartment buildings (andelsboligforeninger).
  • A questionnaire study distributed to a representative sample of residents in apartment buildings in the municipalities of Copenhagen and Frederiksberg.


The analyses of the project’s empirical data indicate that residents in Copenhagen’s apartment buildings generally accept source separation of their household waste. If there is an option to separate a specific fraction and get rid of that fraction in an easy way most people will use that option most of the time. It even comes across as a general norm that people should separate their waste thereby contributing to the recycling of valuable resources and that people have a personal responsibility for correct waste separation. This general norm is in turn linked to three overlapping framings: (1) the principle that useful materials and things never should be wasted; (2) a general concern for the environmental; (3) the need for nice and clean surroundings.

The extent and quality of people’s waste separation does, however, not only rely on the prevalence of this norm but also on the infrastructural conditions for waste handling and on people’s knowledge and competences.

Easy access appears to be an important factor. Well-functioning, accessible and understandable options for getting rid of the recyclable fractions seem to be a precondition for household participation in source separation. The appearance at an apartment building’s garbage collection point of a new container for a specific fraction can even in itself trigger new waste sorting practices among residents. Similarly, knowledge and competences are crucial. For instance, residents need to know which materials belong in the container for solid plastics (which is not always obvious), they need to be aware that glass, plastic and metal containers should be rinsed before they are discarded, and they need to develop routines for rinsing these fractions without wasting hot water.

Other studies also indicate that that space – or lack of space – in the home is a critical factor; i.e. room for keeping the separated fractions in the home until they are carried to the collection point. But according to the present study space is not as critical a factor, maybe because collection points are located in the apartment building rather than at more remote neighbourhood recycling centres. It appears that if people want to separate their waste – as most do – they find solutions like dedicated bags on door handles or small piles in corners or other types of short term storing of recyclable waste fractions in their home, even when they do not have much available space.

In spite of people’s general acceptance of source separation waste handling is far from problem-free in the city’s apartment buildings. Insufficient and incorrect and other forms of undesirable waste handling occur, including (but not limited to) misuse of garbage chutes for inappropriate objects, soiled pizza boxes in cardboard containers, residual waste deposited in the shed for large items, bottles left at the ground rather than placed in glass containers, un-folded cardboard boxes taking up all space in the cardboard container etc.

These problems are caused by several factors. Firstly, some residents some residents do handle their waste inappropriately, either because they are indifferent towards and do not share the general norm about waste handling or because they are sloppy and do not have time in concrete situations where they want to get rid of their waste, or because it can be difficult to find out how certain types of waste should be discarded. Based on the caretakers’ estimations as well as other parts of the empirical data it is the assessment of this report that up to one fifth of apartment building residents do not participate in source separation, either because they do not want to or because they lack sufficient knowledge.

Secondly, the physical space size and lay-out of the building do not always accommodate the necessary facilities capacity such as containers for all recyclable fractions, sheds for large items or lockers for hazardous waste, which – in combination with insufficient collection frequencies – leads to overloaded containers, incorrect separation, waste on the ground, vermin and unpleasant odours. Moreover, garbage chutes appear to be problematic because they are unsanitary, require disproportionately hard work in a noxious working environment for caretakers, and tend to afford sloppy garbage handling by residents.

These problems affect the quality and quantity of recyclable waste, but also the quality of communal areas – whether in courtyards or basements – of apartment buildings. It is important for residents and caretakers alike to maintain pleasant and sanitary communal areas which can be used for children’s play, barbecuing, and other leisure activities, but waste handling facilities are often located in the very same communal areas, so correct and effective waste handling is important for the liveability of apartment buildings.

Problems in waste handling are usually handled by paid caretakers or by unpaid members of residents’ boards (in flat owner associations and cooperative housing associations), i.e. the intermediaries in apartment building waste handling. Some of them may go as far as to remove misplaced waste items and discard them correctly, but the main function of the intermediaries is to maintain the building’s waste handling infrastructure. They remove whatever items – and sometimes very strange items – which block garbage chutes, garbage sheds and all other parts of the infrastructure. They tidy up basements and courtyards when residents have made a mess. And they communicate existing and new rules through notices, mail messages, Facebook postings, personal advice, and sometimes direct communication to wrongdoers. In this way they keep the waste stream flowing thereby also contributing to the efficacy of source separation.