Energy efficiency (EE) is our “first fuel” and an essential resource in reaching climate goals, reducing dependence on fossil fuels, increasing security of supply, and many other “Multiple Benefits.” However, by their nature, savings are intangible. Demand-side EE measures are typically decentralized, heterogeneous, and small-scale opportunities. The difficulties in measurement and verification (M&V) of “Negawatts” are an important and often overlooked barrier to their greater application. M&V is a prerequisite to assess the performance of any energy, water, or CO2-saving measure, and to quantify the savings into physical and monetary units for reporting, re-financing, GHG accounting, or other purposes. However, in practice, M&V is often perceived (particularly by clients) as cumbersome, incomprehensible, and costly. In the broader context, energy cost savings alone are often not a sufficiently strong project driver because they lack strategic relevance for decision makers. As “Multiple Benefits” of EE become better understood, the value of quantifying savings to a high degree of accuracy may be declining, creating opportunities for more flexible M&V standards. As a new methodology, this conceptual paper proposes to combine simplified M&V (sM&V) for individual EE measures with quality assurance instruments (QAIs) to verify functionality. This “sM&V + QAI” approach is less cumbersome, less costly, and easier to comprehend than standard M&V approaches, particularly by clients, financiers, and other non-M&V experts. It has been reviewed by international experts and successfully tested and evaluated in the field. Multiple case studies are reported to verify its practical feasibility.

Building retrofits are strongly dependent on the individual refurbishment/rehabilitation cycles of buildings. In order to achieve the targeted climate goals for the building sector, it is necessary to make the best possible use of refurbishment opportunities for energy retrofits. Furthermore, it must be considered that the younger the building, the lower the potential for energy savings. The most challenging, yet required, energy retrofits are all yet to come. Given the importance of the refurbishment cycle, the question arises as to what the theoretical refurbishment rate is, what the actual energy retrofit rate is, and what it needs to be in order to meet the climate targets for the residential building stock. The aim of this paper is to model the evolution of the size and retrofit status of national building stocks. This is to be done against the background of the deviation from the actual and theoretical refurbishment cycle. Using current statistics and the past development of the German residential building stock, central parameters like living space, new construction, deconstruction, and the retrofit rate are modeled endogenously. For the latter, influences of economic conditions are implemented through an exogenously set black box variable. The retrofit rate represents a deep energy retrofit and thus allows an easy connection of the model with energy parameters for building classes defined in the web database TABULA for 20 European countries. The results are of relevance for modeling the energy efficiency status of the building stock and deriving suitable conditions for increasing retrofit rates also in other countries. The results show that increasing the energy retrofit rates to 2%/a or more is largely unrealistic. Instead, the focus should be on weak points, especially where short-term savings are concerned. This applies in particular to facades, basement ceilings, and heating systems as well as the efficient use of energy in buildings.

At global scale, the building sector accounts for 40% of total energy end use and almost 35% of greenhouse gas emissions. This makes it one of the most important sectors to focus on for reaching the 1.5–2 °C target of the Paris Agreement, to enhance energy security of supply and to alleviate energy poverty. The European Union (EU) is often seen as a leader in climate governance, which is also true for energy efficiency. The improvement of energy performance of buildings has been part of EU public policy for more than 50 years, making the EU a pioneer in the policy domain. Based on a semi-structured review of the scientific literature (N = 90), this paper is aimed at drawing the lessons from research on governance of energy-efficient and zero-carbon buildings in the EU. As for the findings, there is a multitude of policy instruments developed on different levels of governance, more or less integrated and managed by different actors and no single instrument is sufficient to stimulate energy-efficient and zero-carbon buildings. Five key challenges are identified in the governance literature examining the transition towards energy efficiency and zero-carbon buildings. An ambiguous leadership, heterogeneity of implementation, lack of incentives, limitations of non-regulatory policies and market-based instruments, and limited diffusion between governance levels. We also conclude that most policy instruments focus on new buildings which is problematic since the greatest challenge in the transition is the renovation of the large existing building stock.

This study aims to provide insights into the factors shaping electricity demand in Swedish industrial sectors using the nonlinear version of the autoregressive distributed lag model (NARDL). This approach captures the complex short- and long-run relationships between uncertainty and electric power use in Swedish industrial sectors. The results reveal sector-specific responses to uncertainties and asymmetries in electricity use patterns. By examining the entire industrial sector in Sweden, this approach uncovers underlying issues and hidden patterns, while also providing insights into the functioning and behaviour of industrial systems. The rapid electrification and new green industrialisation initiatives in Sweden, coupled with the integration of a circular economy, underscore the importance of understanding the dynamics of electricity use in the face of uncertain shocks. This knowledge is vital for ensuring, amongst other things, grid stability, mitigating the need for costly peaking capacity, and identifying potential challenges in the interconnection of energy and material circular flows.

Occupant behavior is among the main causes for the mismatch between simulated and in-use energy performance of buildings. One of the strategies considered capable of reducing user’s behavior induced energy consumption, while increasing indoor environmental quality is the application of Building Automation and Control Systems (BACS). In this study, three building user’s profiles have been considered depending on their energy consumption. The energy savings due to BACS class increase have been calculated, and a cost–benefit analysis (CBA) has been performed to evaluate the feasibility of different scenarios. Additional co-benefits perceived by the individuals have been accounted for in the form of willingness-to-pay (WTP). The methodology is applied to two case studies: a nearly zero-energy building (NZEB) rural single-family house and a recently renovated dwelling in an apartment block. The results show that the main reductions are achieved by the users’ behavior alone, and the adoption of BACS is economically feasible only when an incentive program is in place, and the WTP is repeated as a recurrent co-benefit over the years. In particular, relying only on energy reduction due to higher BACS class introduction is not economically desirable. The greatest savings are achieved by the behavioral change of the user when coupled with BACS, supporting their potential role in improving user’s energy literacy. Finally, incentive schemes are necessary to reduce the investment costs of such projects, being these the most influential variables in the feasibility of BACS applications.