Conference Agenda

To further reduce greenhouse gas emissions, calculating the carbon footprint of buildings is a critical criterion for assessing their sustainability. According to the EU’s new Energy Performance of Buildings Directive, the life-cycle carbon assessment will be mandatory from 1 January 2028 for all new buildings with a useful floor area greater than 1000 m2 and from 1 January 2030 for all new buildings. Therefore, the Guidelines for low-carbon buildings of Slovenian public housing funds were introduced in 2024 to help design, procure and assess carbon emissions of publicly-funded residential buildings in Slovenia. This study aims to assess the embodied carbon of the selected publicly-funded multi-apartment buildings following the LCA methodology presented in the guidelines. The methodology focuses on the production-related embodied upfront emission (modules A1–A3 per EN 15978). The functional unit also includes the parking infrastructure, which can include detached or underground parking garages. The embodied carbon is presented by the global warming potential (GWP) indicators: total (GWPt), biogenic (GWPb) and fossil (GWPf). The GWP indicators were calculated for each of the selected building projects. Depending on the project, this can include a single multi-apartment building or residential neighbourhoods consisting of multiple residential buildings. Then, the data was further analysed using descriptive statistics and compared to the data gathered from other countries in the EU. The material-related carbon footprint hotspots were identified and compared via various normalisation bases (housing unit number, floor area and per capita). The results showed that in the final embodied carbon footprint of the buildings (life-cycle phases A1–A3), the largest share is contributed by the elements of the load-bearing structure. The latter thus represents the most significant potential for optimising (reducing) the embodied carbon footprint of similarly designed buildings. Additionally, the data highlights that underground parking facilities, constructed as cast-in-place reinforced concrete structures, contribute an important share of the environmental burden. The integration of parking space in multi-residential building projects is therefore identified as an important design related influencing factor for embodied carbon reduction.

Life Cycle Assessment (LCA) is an effective method for estimating the envi-ronmental impact of products that are widely used in the construction sector. Various techniques are available to calculate and estimate the environmental impacts of buildings and their materials throughout their life cycle. These approaches deliver scientifically robust evidence to identify materials and products that are environmentally optimal by tracing the origins of major en-vironmental impacts. Over the last ten years, the volume of scientific re-search and publications on LCA within the construction sector has grown twofold. The aim of this paper is to present the environmental assessments of building materials used in a typical family house in Central Europe using different LCA methods (ReCiPe, Impact World, CML, Environmental Foot-print, IPCC, BEES and TRACI). The environmental indicators calculated were used to identify the constructions with the lowest and highest environ-mental impact in each environmental category. The findings revealed that the absolute values of the calculated climate change, expressed in terms of GWP, varied slightly and all methods consistently identified the same struc-tures as having the minimum and maximum climate change impact. The structures with minimum GWP values represented the materials of horizontal structures and the maximum values represented the materials of vertical structures. However, for the other environmental categories, the results were not as clear-cut and different structures were identified as the best or worst for the different methods.

Mitigating the environmental impacts of building construction is currently a key area of applied Life Cycle Assessment research and is receiving increasing attention in the European regulations too. This paper introduces the results of the upfront carbon footprint calculation for a 7-story + 2 basement mid-rise multi-story residential building with 906 technically feasible design variants. The goal of the research was to clarify the carbon range of the available technical construction solutions and reveal the improvement potential with available low-carbon technologies. The novelty of this simplified approach is that it is not based on inhomogeneous data from existing building stock and does not use a limited number of design variants produced by dedicated design software. However, it is intended to cover the whole available design spectrum with generated building solutions with uniform technical parameters and life cycle assessment scope. The analysis method is based on the statistical evaluation of a database of technically equivalent virtual building variants created with a full combination of different building structural designs, common in current construction practice. Calculation has shown ~10-15% advantages of purely timber frame or CLT structural solutions over RC and hybrid RC structures. The analysis also showed that for the building materials studied, only concrete’s carbon intensity has a significant effect on the building level.

The research looked at the environmental impact of historic buildings from different periods, from their creation to the present day. Contemporary attitudes and the increasing use of energy are major drivers for tightening energy standards. Compliance with stringent standards encourages practitioners and researchers to improve the environmental impact of buildings by looking deeper at the root of the problems, which requires an understanding and analysis of the whole life cycle of buildings. People's attitudes have changed, both in terms of raw materials and energy use. We tend to waste our resources regardless of environmental impact and sustainability, and forget that the existing building stock represents both tangible and intangible assets.

The article is a literature review of research published in recent years in the field of environmental impact assessment of historic buildings. It analyses and summarises the questions that researchers have sought to answer, the methods they have used, the data and databases they have relied on, the calculations they have carried out and the results they have obtained. We would like to explore how curricular the life cycle analysis of historic buildings is at present.

When collecting the sources analysed (research papers), the aim was to find a large number of sources presenting case studies. The case studies were classified in terms of geographical location; the size and function of the building stock studied; the historical age of the buildings and, in this context, the materials and structures used; the extent of extensions, alterations and modernisation carried out.

The literature search will provide insights into the current state of the science on how the value of historic buildings can be quantified by comparing the material costs of the buildings with the environmental impacts associated with their operation. The analysis of the sources will identify gaps in the analytical methods and research gaps that should be focused on in further research. Based on the experience gained, it will also be possible to formulate and conduct our own domestic research. The article contributes to a deeper understanding of the calculation of environmental impacts in historic buildings, which can help to comply with legislation, energy and environmental requirements and to protect existing buildings.

The EU Taxonomy aims to guide investments toward sustainable economic activities through a harmonized framework for environmental classification, including the construction sector. In Sweden, building sustainability has traditionally been assessed using certification systems such as Miljöbyggnad, BREEAM-SE, and LEED. Since 2021, some of these systems have begun incorporating EU Taxonomy criteria, but the impact of this integration remains unclear. Questions persist regarding whether the Taxonomy improves sustainability outcomes, simplifies or complicates certification processes, and how it is perceived by practitioners. This study addresses these questions through a mixed-method approach, combining a targeted literature review with a survey of Swedish professionals, including sustainability consultants, developers, and certification assessors. The findings indicate that while the Taxonomy is becoming increasingly relevant, professionals report challenges such as unclear guidance, limited alignment with existing systems, and a narrower scope than current certification frameworks. Concerns about green-washing and weak verification were also noted, alongside mixed views on financial benefits. The study concludes that the EU Taxonomy and certification systems serve different but potentially complementary roles. Better alignment could strengthen their combined impact. Future research should explore how certification systems can support compliance under emerging EU policies, including the Omnibus proposal and the Green Claims Directive, and assess their long-term effects on sustainability practices in the building sector.

Hungary, as a member of the European Union, adapts to the EU’s climate strategy and energy policy, which includes the implementation of the Energy Performance of Buildings Directive (EPBD). The first version of EPBD was published in 2002. A recast was formulated in 2010, which were revised in 2018, and in 2024. Based on the revision of EPBD in 2018, the Hungarian national decrees had to be revised. After the COVID and the energy crisis, finally in 2023, the 9/2023. ÉKM decree was formulated, and replaced the former 7/2006. TNM decree. The new decree modified the calculation and certification methods of buildings energy performance in Hungary according to EPBD and the up-to-date European standards. The significant changes in the regulation rise the questions of how the calculation and certification results have changed, and how the building designs should change to meet the modified requirements. In this research, residential buildings were examined according to the energy calculation and certification methods defined in the old and the new decrees. Eight relatively small residential buildings were selected from the author’s architectural design praxis, and energy calcula-tions were made in two versions, according to the two regulations using the Auricon Energetic software. The partial results of the calculation, and the final results of the certificates were compared in pairs. The differences in the results were identified, and the reasons were revealed behind them. The research can also provide useful conclusions for the architectural and building engineering design of new nearly zero energy buildings.