Recently, there has been an increase in apartments with a large number of inhabitants, i.e., high residential density. This is partly due to a housing shortage in general but also increased migration, particularly in suburbs of major cities. This paper specifies issues that might be caused by high residential density by investigating the technical parameters influenced in Swedish apartments that are likely to have high residential density. Interviews with 11 employees at housing companies were conducted to identify issues that might be caused by high residential density. Furthermore, simulations were conducted based on extreme conditions described in the interviews to determine the impact on the energy use, indoor environmental quality, and moisture loads. In addition, the impact of measures to mitigate the identified issues was determined. Measures such as demand-controlled ventilation, increase of a constant ventilation rate, and moisture buffering are shown to reduce the risk for thermal discomfort, mold growth, and diminished indoor air quality; while still achieving a lower energy use than in a normally occupied apartment. The results of this study can be used by authorities to formulate incentives and/or recommendations for housing owners to implement measures to ensure good indoor environmental quality for all, irrespective of residential density conditions.

During the last few years, there has been an increased number of overcrowded apartments, due to increased migration but also housing shortage in general, particularly in the suburbs to major cities. The question is how the indoor environment in these apartments is affected by the high number of persons and how the problems related to high residential density can be overcome. This paper aims to specify the problem by investigating and analysing the technical parameters influenced by residential density in Swedish apartments built between 1965-1974. To map the situation, 11 interviews with employees at housing companies were conducted. Based on extreme conditions described in the interviews, simulations of the indoor climate and moisture risks at some vulnerable parts of constructions were made. Simulations were focused on moisture loads and CO2 concentrations as functions of residential density and ventilation rate. Finally, measures to combat problems associated to overcrowding are suggested. The aim is that the results should be used by authorities to formulate incentives and/or recommendations for housing companies to take actions to ensure a good indoor environment for all, irrespective of residential density conditions. © The Authors.

The sharing of indoor space can improve space and energy efficiency. The drivers and barriers to space-sharing initiatives are investigated from the perspectives of building users and building sector practitioners, based on interviews and a workshop. The role of energy performance metrics in promoting space efficiency is further analysed through a literature review. From the users’ perspective, space sharing can be understood through the interplay between tangible aspects (e.g. concrete benefits derived from sharing), organisational aspects (e.g. common decision processes and conflict resolution) and social aspects (e.g. group identity and consensus on appropriate behaviours). From the perspective of architects and property owners, shareable spaces require features such as flexibility and multifunctionality. The design of such spaces is limited by regulatory issues (e.g. building regulations poorly accommodate shared facilities) and business-related issues. One such issue is that building performance metrics normalised based on floor area do not incentivise the efficient use of space. A review of complementary metrics is provided, covering parameters such as number of users, layout, time of use, etc. Each metric serves a particular purpose; therefore, a set of complementary metrics can be used to support decisions at different phases of the building’s life cycle.

Practice relevanceImproving space efficiency (e.g. by sharing indoor space) is a key strategy to meet simultaneously the future demand for facilities in cities and fulfil environmental objectives such as a reduction of climate change impact in the building sector. A clearer understanding of the specificities of space sharing is provided from the perspectives of building users and practitioners. This will assist practitioners to understand the needs of other stakeholders. Regulatory and business-related barriers to space-sharing initiatives are highlighted as a first step towards overcoming these barriers. Guidance is provided on complementary energy performance metrics appropriate for space efficiency. These metrics can be used to support various decisions during the different stages of a building’s life cycle.

Renovations of the housing rental stock have become a political concern since they have been claimed to drive gentrification and affect tenants’ everyday lives as well as long-term housing conditions. Furthermore, new actors have entered the market, partly as a result of high supply on the international capital markets creating a flow of capital into market segments. This has led to a critique of private equity in the housing sector, and raised the question of the extent to which ownership of the rental stock matters for housing affordability. Yet there seems to be little systematic research on this topic. This study uses a unique dataset covering the entire rental housing stock in Sweden to address whether there are differences in renovation investments between different ownership groups. The purpose of this article is to increase understanding of how ownership affects renovation processes, and specifically to analyse to what extent, and how, private and public actors differ in renovation and rent setting decisions. Our results demonstrate that public housing companies raised rents less and renovated more, particularly in the lower-income segments of the multi-family building stock between 2014 and 2020. © 2023 The Author(s). 

A public housing company has applied a new renovation strategy, comprising no standards raising and thus rent-raising measures, in 20% of its apartments. Prior to renovation, the tenants were given the opportunity to choose renovation options involving different standards and costs after renovation. The purpose of the study is to follow up and give feedback on the renovation strategy. The aim was to evaluate implementation of the strategy in practice using a case study, in terms of the tenants’ opportunity to influence and the housing company’s profitability. To follow up, two methods were used: a survey of the tenants’ perception of choosing renovation options, and a financial assessment of the profitability based on the renovation cost and rent increase for different choice scenarios. The results from the survey show that the tenants appreciate being able to choose between different renovation options as it gives them the opportunity to decide on their housing costs and standard. With more than half of the tenants choosing the maintenance option involving a very low rent increase, the dividend yield will not be high enough to make the renovation profitable, but if only 20% had chosen the maintenance option, the dividend yield would be more feasible in the long run.

Energy poverty has been kept at bay in Sweden for the past decades owing to several beneficial circumstances. However, geopolitical pressure and an accelerating energy transition are changing the circumstances and exposing vulnerabilities to energy poverty in Sweden particularly connected to electricity price peaks. The circumstantial nature of the exposed risks for energy poverty motivates a conceptualisation of the concept in Sweden through the energy vulnerability framework. Also recognising that flexibility is an important ability to be able to dodge short-term price peaks, this paper combines the energy vulnerability literature with the concept of flexibility capital. Using national survey data from 2021, this study seeks to explore vulnerability to heating-related energy poverty in Swedish single-family housing by analysing factors influencing households' self-perceived ability to pay for heating as well as their self-perceived flexibility capital. Logistic regression models revealed that there are geographic as well as sociodemographic factors influencing the energy vulnerability experienced by Swedish households. Extending the understanding of energy poverty vulnerability beyond mere heating affordability provides a more nuanced understanding of the different types of risks that may emerge among households; for example, low affordability combined with low flexibility capital increases the risk for financial effects of energy poverty, whereas low affordability combined with high flexibility capital increases the risk for energy poverty affecting comfort, convenience and wellbeing. By integrating energy vulnerability with flexibility capital, this paper contributes to a more holistic understanding of challenges connected to a transitioning energy system in general and in the Swedish context in particular. © 2022 The Author

While the energy transition of the EU housing stock is now being intensified with the launch of the Renovation Wave, economic inequalities are increasing in many OECD countries, which has effects on housing-related inequalities and the demand of affordable housing. The Renovation Wave is thus an opportunity to improve housing quality for low-income households, but also entails risks for increased rents. In Sweden, the standard of housing is relatively high and energy poverty in multifamily housing is rare, meaning that there are limited social benefits to be achieved from extensive energy retrofitting; moreover, Sweden lacks a social housing sector, which limits protection of the worst-off residents. This paper thus explores whether the limited social benefits of the Renovation Wave weigh up against the risks that it entails for the worst-off in the Swedish context. This is done within a normative framework for just energy transitioning that is developed within the context of the Renovation Wave and increasing economic inequalities, consisting of four ordered principles: (1) The equal treatment principle; (2) The priority principle; (3) The efficiency principle; and (4) The principle of procedural fairness. Analysis showed that to be considered just according to our framework, the Swedish energy transition of housing should, in contradistinction to what is suggested in the Renovation Wave, limit the imposition of extensive energy retrofitting in low-income areas. Finally, having identified a mismatch between the most effective approaches in terms of energy savings and the most acceptable approaches in terms of social justice, we offer policy recommendations on how to bridge this mismatch in a Swedish context. © 2021 by the authors. 

Energy Performance Certificates are currently one of the most extensive data sources about the energy performance of the EUs building stock and consequently provide support for researchers and policy makers in energy regulation. As Energy Performance Certificates are being renewed, there are new possibilities to study energy performance development over time and to evaluate the building-specific effect of energy policies and measures. This paper aims to explore this possibility. In Sweden, owners of multifamily buildings had to obtain their first Energy Performance Certificate no later than the end of 2008, and with a period of validity of 10 years many owners have now obtained a second Energy Performance Certificate for their building(s). This enables unprecedented quantitative, building-specific evaluations of the change in energy performance over time. However, comparability between old and new Energy Performance Certificates must be assured. This study develops a novel three-step method to attain comparability between old and renewed Energy Performance Certificates. Results show that while many pairs of Energy Performance Certificates were considered comparable, procedural changes in methods for determining heated floor area in Swedish Energy Performance Certificates caused an overestimation of energy performance improvement of approximately 7 kWh/m2 per building which had to be corrected for. The results of this paper indicate that old and renewed Energy Performance Certificates can be utilised to successfully map development of energy performance and enable evaluation of the impact on energy performance from policies and measures that have been carried out between the two points of audit. © 2019 The Authors

Although renovation costs can lead to rent increases in energy retrofitting, it is often assumed that reductions in energy costs will counterbalance the rent increase. In Swedish multifamily housing, energy costs for heating are however generally included as a fixed component in the monthly rent, meaning that the rent increase after energy retrofitting corresponds to the net change in rent level as well as energy costs for heating. This makes Sweden a methodologically advantageous setting for studying tenants' cost burden of energy retrofitting. The aim of this study was thus to investigate how energy performance improvement has affected rent increases in Swedish renovation projects between 2013 and 2019. Utilising a national database of multifamily housing, it was found that energy retrofitting entailed a cost relief for tenants in renovation projects with smaller investments. However, in renovation projects with larger investments, energy retrofitting entailed a cost burden for tenants. Moreover, public housing companies had conducted a high share of the extensive energy retrofits, leading to low-income tenant groups being disproportionately subjected to cost burdens of energy retrofitting. On the contrary, light energy retrofits with a cost relief for energy efficiency had been rather evenly distributed across income groups. These results indicate ongoing conflicts with the ability-to-pay principle in the energy transition of Swedish multifamily housing, and suggest that if low-investment energy retrofits are not sufficient for upcoming objectives and requirements, subsidies could be needed to compensate low-income tenants for the cost burden of extensive energy retrofitting. © 2022 The Author(s)

Improving energy performance of the housing stock continues to be an important undertaking in the energy transition of many EU member states. However, tendencies of low-income households generally living in buildings with low energy performance pose a challenge for this transition, and cases of ‘renoviction’ and ‘green gentrification’ are becoming more and more noticed in the scientific community. More so, questions regarding the distributive justice of costs and burdens in the energy transition of the housing stock have been raised. In this paper, we approach this problem from a perspective of energy performance metrics. Although energy performance (kWh/m2, year) is generally lower in buildings inhabited by low-income households, residential density—and thus building utilisation—tends to be higher. By measuring per capita energy use instead of area-normalised energy use, we investigate if a high residential density can offset a low energy performance and change the perception of which buildings are considered energy inefficient and which are not. Results showed that by measuring per capita energy use instead of area-normalised energy use, energy inefficient buildings were found in high-income city centres instead of in low-income suburbs of Swedish cities. Moreover, there has been an unjust distribution of the imposition of the energy transition over the past decade where the residents with the initially lowest per capita energy use have carried a disproportionately high share of the energy savings. This suggests that a change of energy performance metrics could offer an approach for a more socially just and sustainable energy transition of the housing stock. © 2020 The Author(s)

Improved energy efficiency in the housing stock is an important undertaking in the energy transition but is associated with both opportunities and risks. While there are possibilities to reduce energy inequalities in the housing stock, inequalities also risk being aggravated as actions for energy efficiency usually aim at the least energy efficient - and thus sometimes the least privileged - parts of the housing stock. In this paper, we use two different energy performance metrics (kWh/m2 and kWh/capita) to investigate the energy inequality in the Swedish multifamily building stock and explore the effects of these inequalities in the energy transition. More specifically, we investigate the implementation of individual metering and billing of energy for heating, which was recently implemented in the least energy efficient part of the housing stock. It was found that low-income households were overrepresented in the affected buildings. The consequence of this implementation is thus that the strongest protection against energy poverty in Sweden (collective billing for heating) is removed in a part of the housing stock where two of the predictors for energy poverty - low income and low energy performance - are overrepresented. It was concluded that acknowledging inequalities is crucial to avoid risks associated with the energy transition. 

To ensure building construction with low heating demand, efficient use of sustainable energy carriers, and neutrality between heating technologies, Sweden recently introduced weighting factors (WFs) for different energy carriers which are now used in Energy Performance Certificates (EPCs). As EPC ratings are gaining increased influence in Swedish energy policy and regulation, with recent examples of buildings' EPC rating acting as base for imperative regulatory requirements, the introduction of WFs is likely to have significant effects on how policy and regulations are distributed in the multifamily building stock. As residents often are directly or indirectly affected by policy that either impose or trigger measures to be undertaken in their building, the aim of this paper is to analyse how WFs affect the assessed energy performance of buildings in different resident income groups. The results show that overall, reduced energy performance from WFs was more common in high-income areas than in low-income areas. However, although the total number of buildings in the lowest EPC ratings was reduced after introducing WFs, the resulting income distribution among worst-performing buildings was more skewed towards low-income households than before introducing WFs. As imperative regulatory requirements previously have targeted worst-performing buildings, these results indicate that energy-related inequalities in the housing stock have become more prominent and should be considered as to not disproportionately burden low-income residents in the energy transition of the housing stock.

Building databases are important assets when estimating and planning for national energy savings from energy retrofitting. However, databases often lack information on building characteristics needed to determine the feasibility of specific energy conservation measures. In this paper, machine learning methods are used to enrich the Swedish database of Energy Performance Certificates with building characteristics relevant for a chosen set of energy retrofitting packages. The study is limited to the Swedish multifamily building stock constructed between 1945 and 1975, as these buildings are facing refurbishment needs that advantageously can be combined with energy retrofitting. In total, 514 ocular observations were conducted in Google Street View of two building characteristics that were needed to determine the feasibility of the chosen energy retrofitting packages: (i) building type and (ii) suitability for additional façade insulation. Results showed that these building characteristics could be predicted with an accuracy of 88.9% and 72.5% respectively. It could be concluded that machine learning methods show promising potential to enrich building databases with building characteristics relevant for energy retrofitting, which in turn can improve estimations of national energy savings potential.