Description: The concept of sufficiency - reducing energy uses beyond technical efficiency - is far-reaching and requires a reflection on human needs, energy services, urban structures, social norms, and the role of policies to support the shift towards lower-energy societies. In recent years, a growing body of literature has been published on energy sufficiency in various disciplines. However, there has been limited exchanges and cooperation among researchers so far, hindering the visibility and impact of this research. This paper presents an assessment of where sufficiency research stands, especially in the perspective of policy-making. It is the first overview paper issued in the context of the newly-founded ENOUGH network - International network for sufficiency research & policy, established in 2017. In the first part, we provide a condensed literature review on energy sufficiency, based on dozens of recent references collected through the network. Through four main themes (the nature of sufficiency, the challenges of modelling it, the barriers to its diffusion, and the approaches to foster it), we summarise the key issues and approaches. We then present what the scholars themselves see as the priorities for future research, promising sufficiency policy options, and key barriers that research should help overcome. We collected their views through a questionnaire completed by more than 40 knowledgeable authors and experts from various disciplines. We finally build on the previous parts to draw some recommendations on how sufficiency research could increase its impact, notably in relation to policy-making.

Description: The Fit for 55 package stipulates a fair, competitive and green transition by 2030 and beyond. As part of this, increasing attention is given to the decarbonisation of the building stock: only 1 % of buildings in Europe are retrofitted each year, a number which must double if the EU is to meet its 2050 targets. Significant energy efficiency investments are needed, whilst the planned expansion of the EU-ETS to the building sector in 2026 will likely pass the carbon cost onto the consumer. This will increase the cost burden placed on low-income households, exacerbating energy poverty, if these two strategies are not counterbalanced by adequate policies and support mechanisms. The European Private Rented Sector (PRS) is often side-lined by policymakers when implementing energy efficiency policies to tackle energy poverty. As many as 1 in 10 Europeans spend 40 % or more of their income on housing costs, with those in the PRS struggling with energy-related problems, such as poor energy efficiency and maintenance, to a much greater degree than the general population. Understanding these challenges and creating targeted policies is of critical scientific and policy importance. To date, a pan-European policy on how to address energy poverty and energy efficiency improvements in the PRS is lacking; current European Union instruments to address such issues (including the Fit for 55, and the Clean Energy Package that preceded it) lack a dedicated approach towards the complex structural issues embedded in the European PRS. What is more, there is a limited understanding of the character of energy poverty in such residential dwellings, as well as policies to address energy injustices. We therefore examine current and historical disparities in energy poverty between the EU's PRS tenants and the general population by analysing a variety of quantitative indicators which reflect different dimensions of energy poverty. We then take stock of the policy landscape, identifying energy efficiency policies tailored to alleviate energy poverty in the PRS and common challenges. We subsequently interrogate possible solutions, drawing on existing good practice policies. In so doing, we aim to reduce the sector's political invisibility by addressing the lack of disaggregated, targeted data and dismantling barriers that currently lead to the PRS being disproportionately affected by energy poverty.