Despite increasing popularity of LCA in policy circles, few empirical studies aim to understand how legislative developments influence existing LCA-based practices within targeted organisations. This paper examines the development of building-specific LCA practices at four Swedish building companies between 2017 and 2025, a period in which legal requirements for building climate declarations were introduced. The results show a remarkable increase in the volume and variety of LCA-based practices in building projects. The studied cases successfully moved beyond legal compliance by carrying multiple LCA-based practices in parallel. The importance of multiple LCA-based practices for sustainable building implies that caution is advised when developing novel LCA-oriented legislation. Stricter regulations may have unintended negative effects on sustainable building when the capacity of organisations to align LCA use with other legitimate concerns in building projects is stifled. Paying closer attention to the effects of legal requirements on existing LCA-based practices is therefore recommended.

Transitioning existing urban neighbourhoods to Positive Energy Districts (PEDs) requires integrated planning to address complex energy, cost, and lifecycle carbon emission challenges. Existing integrated methodologies optimize buildings individually and overlook local energy systems potentials like shared renewables and battery storage. Moreover, existing studies on optimization of on-site renewable energy sources and building retrofitting often rely on simplified typical-day representations, falling short in capturing critical operational dynamics over tim0e. This paper introduces and applies an integrated urban building energy modelling and bi-objective mixed-integer linear programming framework. The framework co-optimizes building retrofits and heating systems, PhotoVoltaic (PV) systems, and Battery Energy Storage System (BESS) capacities over a 10-year horizon with hourly resolution, targeting minimal lifecycle costs and total carbon emissions (operational and embodied). Applied to a 1950s neighbourhood in Gothenburg, Sweden, the analysis demonstrated that achieving full PED status (net-zero energy import, net-zero carbon, and energy surplus) with the evaluated interventions is highly challenging. While optimized solutions reduced the grid dependency (to similar to 63 % with PV and BESS under volatile prices) and overall carbon emissions (by similar to 13% compared to baseline), neither complete net-zero energy import, full carbon neutrality including embodied impacts, nor an energy surplus were realized. The study quantitatively identified critical trade-offs between investment costs, embodied carbon, operational performance, and resilience. Optimal solutions were sensitive to local conditions, notably low-carbon district heating and electricity price volatility. The proposed framework provides a decision-support tool for strategic PED planning in existing urban areas, enabling an exploration of complex techno-economic and environmental trade-offs.

The construction sector has been struggling to implement plastic waste management strategies that promote plastic circularity, and limited understanding persists regarding the barriers to reducing, reusing, and recycling plastic waste. This knowledge gap is compounded by the diversity of plastic products, the unique role of construction companies in the circular economy, and the complexity of the construction plastics’ value chain. This study aims to generate knowledge to support construction companies in improving plastic waste management in the European context. We investigate relevant barriers through a life cycle perspective and considering the diversity of construction plastics. By compiling product data, a construction plastic product list was created, covering 38 product types across seven categories with 18 polymer options. In parallel, a literature review and thematic analysis was conducted to construct a life cycle-based and circularity strategy (Reduce, Reuse, Recycle)-categorized barrier overview. The diversity of construction plastics was considered in the barrier analysis, revealing how the relevance of specific barriers varies across products.A total of 129 barriers to recycling, 124 to reuse, and 39 to reduction were identified. Results highlight that the Construction life cycle stage faces the highest number of barriers across all three strategies. These barriers are predominantly activity-related, such as 17 “Collection & Sorting” barriers for recycling, 12 “Design” barriers for reuse, and 4 “Installation” barriers for reduction. The life cycle stage-based, strategy-specific, and product-specific perspectives on barriers provide a structured foundation for construction companies to set strategic priorities and develop targeted and effective plastic waste management strategies.

As the Swedish electricity system transitions to cleaner and more sustainable energy sources, local energy communities (LECs), comprising groups of consumers and producers who share locally generated energy and energy-related infrastructure, are emerging as a promising solution to support the power grid. This paper aims to quantitatively evaluate the potential of LECs to improve the efficiency and sustainability of the Sweden’s electricity system. To this end, two real-world demonstration sites in Sweden are analyzed: Jättesten, representing a residential load, and Chalmers Campus, representing a commercial load. The key performance indicators considered in these case studies include total annual operating cost, self-consumption (SC), self-sufficiency (SS), and peak shaving capability. The results show that combining residential and commercial loads within a single LEC significantly improves overall performance by leveraging demand diversity. Participation in LECs can reduce annual operating costs by up to 14

Positive Energy Districts (PEDs) have emerged as a key urban innovation to accelerate the transition toward climate neutrality and sustainability in cities. This study explores the integration of backcasting methodologies and Digital Twin (DT) strategies to advance the development of PEDs. A two-step approach was employed: participatory backcasting workshops to co-create long-term visions and actionable strategies, and DT technology applications tailored to three Urban Living Labs (ULLs) in Vienna (Austria), Gothenburg (Sweden), and Sakarya (Türkiye). The backcasting process facilitated the identification of pathways to energy efficiency, renewable energy integration, and decarbonization, creating a structured yet adaptable roadmap for PED development. DT functionalities—including Digitize, Visualize, Simulate, Predict, and Orchestrate—transformed these plans into operational tools, enabling real-time monitoring, predictive modeling, and adaptive energy management. The study underscores the critical role of stakeholder collaboration in aligning local priorities with sustainability goals and demonstrates the capacity of DT frameworks and PEDs to enhance energy efficiency in diverse urban contexts. However, challenges such as scalability, resource intensity, and sustaining long-term engagement persist. This dual approach highlights the potential of integrating participatory planning with advanced digital tools to bridge the gap between visionary energy goals and practical implementation, offering a replicable framework for urban energy transitions and decarbonization.

Road transport was responsible for 24% of all carbon dioxide emissions in the EU in 2020. The majority of the transport sector's carbon emissions is related to the operation of vehicles, followed by infrastructure construction and rehabilitation. Roadside equipment, such as noise and safety barriers make a small contribution. Nevertheless, road infrastructure requires extensive use of natural resources and is a major generator of waste, as well as comprising assets with a lifespan of up to 100 years. The PROCEEDR project, funded by the CEDR Transnational Road Research Programme Call 2020 Resource Efficiency and Circular Economy created a software tool to enable National Road Administrations as well as roadside equipment manufacturers to find innovative and sustainable solutions to ease the transition from linear to circular economy in the field of roadside infrastructure. This paper presents a unique software tool that closes a research and knowledge gap and has been tested and validated in several case studies. The work is also based on a state-of-the-art inventory and analyses performed during the first part of the project. We describe the tool development process, benchmark the tool against other available tools and conclude with a critical discussion on points for improvement.

This study aims to better understand the substantive effectiveness of life cycle assessment (LCA) in practical settings. While LCA has aspired to inform decision-making for decades, it is clear that many good LCA studies are not followed by tangible reductions in product environmental impacts. This raises the question whether the underlying model of LCA use does justice to the practical reality of decision processes in projects and organisations. An ethnographic study of a building product development project has been conducted, with a special focus on its use of LCA. Rather than assuming that LCA results lead to more sustainable decisions, actual events have been analysed where LCA influenced the development project over a period of 3 years. The data come from interviews (32), first-hand observations (18 days), and project documentation (> 100 documents), including five LCA studies. The analytic process followed an empirically grounded research approach, leading to a detailed process-based description of LCA use in the development project and an analysis of the substantive effects of each LCA study. Studying a single case in detail enabled the identification of effects from LCA use that normally remain invisible. The analysis revealed that the use of LCA in the development project deviated from common expectations. Rather than a straightforward causal relationship between a commissioned LCA study and a specific design decision, LCA use followed a complex sequence of events, including a diverse set of LCA studies, activities, and project outcomes. Together, six deviations from the conventional model of LCA use were identified: (1) multiplicity, (2) partial effects, (3) displaced effects, (4) activity-based effects, (5) heterogeneous actors and activities, and (6) a two-way directionality of effects. These effect types have been grouped into knowledge- and activity-based models of LCA use. Viewing LCA use as informed decision-making does injustice to the manifold ways in which LCA leads to substantive effects in the studied development project. Relying solely on the conventional linear model is likely to disappoint as it guides LCA practices toward producing accurate information efficiently, rather than focusing on the substantive actions, events, and mechanisms that reduce product environmental impacts. Recognising these limitations, practitioners are recommended to consider a wider spectrum of effect mechanisms by drawing on the proposed knowledge- and activity-based models of LCA use. Given the importance of reducing product environmental impacts, more research is needed to understand the substantive effects of LCA.

This paper explores the feasibility of increasing floor area in Swedish multi-family houses during renovations, emphasizing the equilibrium between financial and environmental advantages. The study is framed within the context of the European Union's stringent energy and emissions regulations, employing life cycle assessment (LCA) and life cycle cost analysis (LCC) to evaluate the impact of various renovation strategies. The study incorporates building energy simulations to investigate the results of different renovation scenarios, such as improving walls/roof and changing windows. Furthermore, thorough Life Cycle Cost (LCC) analyses are carried out to identify the most financially advantageous choices that optimize energy conservation. Life Cycle Assessment (LCA) is also conducted to evaluate the environmental consequences of each scenario. The main findings highlight the financial benefits of constructing additional floors, which result in higher income for property owners and immediate revenue for housing companies from selling extra floor space. The strategy of adding floors is environmentally friendly and has a smaller carbon footprint than building new structures, providing a sustainable option for urban growth. The study emphasizes the possibility of achieving substantial energy savings and reducing carbon emissions by incorporating advanced insulation methods, such as insulated roof panels, and upgrading less efficient windows. The research presents a case for the addition of floors during renovation to enhance energy efficiency and sustainability in the Swedish construction industry. It offers a pathway for stakeholders to evaluate the long-term economic and environmental consequences of their renovation decisions.

Existing buildings are valuable resources of secondary material, whose carefully planned recovery and reuse have the potential to decrease the construction industry's resource use, waste generation, and associated embodied carbon emissions. To enable circular strategies, stakeholders across the value chain need varying types of information, including type, quantity, quality, and location of material and building components. The bottom-up approach used in material stock analysis (MSA) provides useful estimates of material stocks in buildings by applying average material quantities to typical buildings. But such results are too coarse to inform circular strategies – building-specific and component-level information is also needed. In that respect, data capture and artificial intelligence open many possibilities. This chapter investigates the level of information needed by stakeholders, and the potential of integrating machine learning, big data, and remote sensing into traditional MSA. The chapter also discusses how these approaches may be leveraged to automatically update buildings' material and component information with the support of a digital twin platform, thereby facilitating the sharing of information with key stakeholders.

This study provides a detailed exploration of how innovation management and digital entrepreneurship models can help transform technical use cases in smart grid contexts into viable business cases, thereby bridging the gap between technical potential and market application in the field of energy informatics. It focuses on the I-GReta project Use Cases (UCs). The study employs methodologies like Use Case Analysis, Portfolio Mapping of Innovation Level, Innovation Readiness Level, and the Tech Solution Business Model Canvas (TSBMC) to analyse and transition from technical use cases to viable business cases. This approach aligns technological solutions with market demands and regulatory frameworks, leveraging digital entrepreneurship models to navigate market challenges and foster energy management, sustainability, and digitalization.

City Digital Twins have emerged as pivotal tools for representing and modelling urban systems. While existing literature emphasizes technological and framework development, limited attention has been given to the practical usability of digital twins in urban planning and decision-making processes. This paper addresses this gap by presenting a participatory approach for a city digital twin (CDTE) development, specifically tailored for supporting stakeholder communication and decision-making in the urban energy transition domain. The study, conducted in three phases, utilizes participatory methods, involving local stakeholders in the development process. The focus is on the Swedish city of Gothenburg, which is actively pursuing climate-neutral goals by 2030. The research integrates quantitative energy modelling and the creation of a web-based interface for the CDTE. The scenarios, grounded in local needs and challenges, explore the impacts of urban development models, climate warming and renovation measures on the building stock. The CDTE, developed and tested through workshops with diverse stakeholders, proves to be effective for the visualization and the discussion of various decarbonization scenarios. Key findings from users’ assessments underscore the significance of clarity and readability in scenario content and user interface for fostering interactions among different administrative spheres. This research contributes to the broader discourse on leveraging City Digital Twins for informed decision-making in urban contexts, providing insights into the practical application of digital twins in addressing the complex challenges of urban energy transition.

Abstract This research develops a multi-criteria framework and Quality Assurance checklist (QA) for Positive-Energy-Districts (PEDs). PEDs have a large potential to contribute to reach urban climate goals but require also changes of planning, development, and transformation processes of neighborhoods. Our understanding of PEDs has been broadened to include aspects of circularity and economic viability, ensuring that PED concepts not only contribute to environmental sustainability but are also economically feasible. In this enhanced perspective, Digital Twins serving as essential carriers of information and facilitators of communication, effectively bridging the gap between different dimensions of sustainable development and practical implementation and monitoring. This study is part of an ongoing European project, Digital Twin for PEDs (DT4PEDs), with Living Labs in three countries: Austria, Sweden, and Turkey. The presented study addresses the central research question, “In what phases can specific requirements be linked to the process to ensure PED development throughout the entire process using a Digital Twin?” within the context of the DT4PEDs project. Based on a participatory workshop with stakeholders from partner countries and a parallel literature review, the study encompasses three key areas. First, it seeks to consolidate property development practices across Austria, Sweden, and Turkey, including both new construction and retrofitting, into a unified framework. Second, it formulates a PED multi-criteria framework, complemented by a Quality Assurance (QA) checklist. Finally, the recommendations for digital twin are proposed to support energy related information flows and stakeholder dialogue.

This study investigates the effectiveness of an Optimal Time Recommendation model (OTR) in encouraging citizens to shift the usage of their home appliances, such as dishwasher to off-peak hours. The research was conducted at the HSB Living Lab + in Gothenburg city, involving 74 participants from diverse social groups, including students, one-person households, couples, and families with kids. The study employed a mixed-methods approach, combining surveys, interviews, and data from self-reporting QR-code or iPad-based web-interface. Participants were provided with personalised recommendations generated by the OTR model, which considered factors such as energy demand, grid load, electricity pricing and level of CO2. The recommendations aimed to assist users in identifying the optimal time slots for operating their home appliances during off-peak, motivated by the lower price, lower CO2 emission or both. Results indicated a positive response from participants across all social groups. Most participants reported an increased awareness of their energy consumption patterns and a willingness to adopt delay shifting practices. However, some frictions and obstacles to adopt shifting time of the behaviour were highlighted as well. The findings from this case study contribute to the existing knowledge on flexibility and Demand-Side Management (DSM). These findings can inform home appliances producers to increase the delay start function usability, policymakers to emphasise the eco-design of the white goods, and researchers in developing effective strategies to encourage energy conservation practices on a larger scale.

Life-Cycle Assessments (LCA) have become a common tool of decision support in the built environment regarding environmental impacts. The goal of this study is to investigate the influence of different LCA approaches and system boundaries on decision support regarding circular design strategies. Three different ways of applying attributional LCA (ALCA) and one consequential LCA (CLCA) are assessed using a case study of a wooden beam with either virgin or reclaimed timber. While the conclusions are not readily scalable, the case study's results indicate that using reclaimed material is environmentally beneficial when applying ALCA. However, when applying CLCA the reclaimed material performs worse than the virgin material. This highlights the potential pitfalls of scaling up solutions based on LCA results without considering the broader consequences. While the current ALCA approach is useful for declarations, it may not provide comprehensive decision support for driving a transition in the built environment.

PROCEEDR aims to create tools to enable National Road Administrations to identify innovative and sustainable solutions to facilitate the transition from linear to circular economy in the field of roadside infrastructure. At the same time, high functional demand and technical performance requirements still need to be met. Therefore, the scope of PROCEEDR is to gather an overview of innovative and sustainable solutions with focus on noise and safety barriers, as well as to provide tools for selecting the most suitable and cost-effective solutions. The paper gives a general overview of the project goals and the methodology to be used, showing also the first activities performed. More detailed results will be presented at the conference in November 2022, while other project results will be presented in the frame of upcoming conferences.

Energy Management Systems (EMSs) play a vital role in managing energy consumption for both utilities and consumers. By using EMSs, utilities can influence on energy usage and ensure a more reliable and efficient grid operation, while consumers can make informed decisions about their energy consumption, leading to significant cost savings and reduced environmental impact. In this paper, a real-time rolling-horizon model is developed for managing energy consumption in public laundries aiming at minimizing energy costs, peak demand, and CO2 emission under the traditional Energy-Based Tariff (EBT) and the Power-Based Tariff (PBT). The developed model can not only reduce energy costs, peak demand, and CO2 emission by optimal task scheduling for washing machines and tumble dryers but also ensure users' preferences for a comfortable lifestyle. To demonstrate the effectiveness of the proposed EMS, several simulations were performed under different scenarios using real data and by a realistic case study in HSB living lab demonstration site. The simulation results reveal that implementing the proposed EMS can significantly decrease energy costs and peak demand in public laundries by 13.59% and 39.40%, respectively, when using the PBT tariff. However, the reduction in energy costs and peak demand is negligible when using the EBT tariff. Likewise, the results indicate that using the EMS and changing tariffs have a minimal impact on CO2 emissions reduction.

Activity-based flexible offices (AFOs) provide a variety of workspaces to meet the need for social interactions and privacy at work. This study investigates the relationship between the design characteristics of AFOs and users' perceptions of visual and acoustic privacy and social interactions. This case study is based on post-occupancy evaluations in three AFO layouts at a public service organization in Sweden. A mixed-method approach is adopted that combines questionnaires and layout analysis. In general, the results showed that while aesthetics received the highest satisfaction scores, office functionality, task support, storage and visual and acoustic privacy received the lowest ratings. Key design characteristics for AFOs were operationalized, observed and exemplified: zone diversity, proportion, readability, spatial enclosure, sharing ratios and functionality of furniture and tools. These insights may contribute to better-informed decisions about the design characteristics that influence privacy and social interactions in AFOs.

In order to meet greenhouse gas reduction goals, cities need to develop robust energy transition strategies relying both on the local capacity of combining social, economic and environmental perspectives in the decision-making process and on the collaboration between different actors to achieve knowledge and data integration. Scenarios are well-established methodological instruments to guide decisions in energy and spatial planning and have been employed to compare possible future pathways and envision the consequences of implementing decarbonization measures. However, qualitative and quantitative scenarios approaches are often disconnected. With the primary goal of supporting the implementation of the energy plan, this study develops for the City of Gothenburg a participatory method to support the alignment of qualitative and quantitative scenarios approaches. Decarbonization actions and drivers of change were discussed and prioritized in workshop sessions with representatives from the energy supplier(s), municipal administrations (city planners, environmental department), and researchers to develop relevant qualitative scenarios descriptions. Based on this, a list of requirements for quantitative scenarios analysis is developed to be, in a next step, translated and integrated into urban building energy models. Findings indicate the importance of early knowledge integration from different fields and highlight the lines of advancement in urban energy modelling to facilitate decision-making towards successful implementation of decarbonization targets.

Buildings are responsible for around 30 to 40% of the energy demand and greenhouse gas (GHG) emissions in European countries. Building stock energy models (BSEMs) are an established method to assess the energy demand and environmental impact of building stocks. Spatial analysis of building stock energy demand has so far been limited to cases where detailed, building specific data is available. This paper introduces two approaches of using synthetic building stock energy modelling (SBSEM) to model spatially distributed synthetic building stocks based on aggregate data. The two approaches build on different types of data that are implemented and validated for two separate case studies in Ireland and Austria. The results demonstrate the feasibility of both approaches to accurately reproduce the spatial distribution of the building stocks of the two cases. Furthermore, the results demonstrate that by using a SBSEM approach, a spatial analysis for building stock energy demand can be carried out for cases where no building level data is available and how these results may be used in energy planning.