The focus of this study is on the hygrothermal and mechanical properties of the elaborated insulating composite based on flax straw. Flax straw is considered as an agricultural waste of organic origin, which has a high sorption capacity and a low thermal conductivity potential due to its natural porosity. Investigations on sorption moisture, thermal conductivity and mechanical properties under laboratory conditions have allowed us to develop a perspective building material suitable for use in ‘green’ construction, especially in rural areas, due to the relative accessibility of the base component. Liquid glass is proposed as a binder. The optimal composition of the filler and binder, sorption moisture, thermal conductivity and surface mapping of the proposed material were investigated. The thermal conductivity reached a minimum value of 0.0728 W m⁻¹ K⁻¹ at relative humidity of 50% during desorption, which is highly competitive to the values for conventional insulation materials on an organic basis. The binder was visually distributed evenly over the surface according to the SEM analysis. Corresponding to the spectral analysis by chemical elements, Na and SiO₂ in total showed 17.69% quantity volume on the composite surface of 2–5 μm in depth. Graphical Abstract

The operational energy efficiency of new buildings in the EU should be at the level of ultra-low or near-zero energy buildings. It is therefore relatively difficult to achieve further energy savings. However, the pre-operational phase—raw material sourcing, manufacturing, transportation, and construction—offers significant energy savings and greenhouse gas reduction opportunities, referred to as embodied energy and equivalent CO₂ emissions. Unlike operational energy, no standard or legislative criteria have yet been established for embodied energy. Setting maximum embodied energy values converted to the unit of heated building area, accounting for building shape factor, and differentiating between high-mass and lightweight constructions are proposed. This study illustrates assessing environmental indicators based on building shape, highlighting the necessity of relative assessments over absolute values to favour energy efficiency. It also emphasizes that precise criteria should derive from authentic data collected during the energy certification and building permitting processes. Integrating assessments of embodied energy and operational energy demand facilitates a comprehensive evaluation of buildings’ environmental performance.

A survey and assessment of the technical condition of basement and semi-basement structures in public buildings aged 60 to 130 years were conducted to evaluate their suitability for use as basic shelters. Based on the survey results, the most adverse impacts were identified, including changes in groundwater levels, improper building operation, and the characteristic damages to underground structural elements. Structural solutions were proposed to eliminate the consequences of these damages. The reviewed cases indicate that the vertical and horizontal waterproofing systems used during construction cannot perform their function throughout the building’s entire life cycle. When designing new buildings, waterproof materials should be used for the enclosing structures of underground premises. While this may have a higher initial cost than membrane or coating waterproofing, considering life-cycle costs, it can provide a positive economic effect and improve the quality and comfort of the indoor environment.

This study investigates the influence of geometric parameters—size, proportions, number of floors, and roof shape—on the environmental efficiency of family houses using a simplified life cycle assessment (LCA) method. The analysis focuses on the product stage (A1–A3), commonly referred to as “cradle to gate,” which encompasses embodied emissions and energy. It demonstrates that even within the limited scope of the product stage (A1–A3), geometric parameters such as floor area, proportions, and compactness exert a decisive influence on embodied environmental impacts. In addition to absolute and per-square-meter indicators, the analysis highlights the importance of the shape factor, defined as the ratio of envelope area to heated volume, as a fairer basis for comparing buildings of different geometries. Similar to its established role in operational energy certification, the shape factor provides a meaningful link between geometry and embodied impacts. The findings suggest that future implementation of the Energy Performance of Building Directive IV (EPBD IV, EU 2024/1275), which mandates the calculation of the global warming potential (GWP) of new buildings from 2028 onwards, could benefit from evaluating both primary energy non-renewable (PENRT) and global warming potential (GWP) in relation to the shape factor, once sufficient data become available. The presented study thus contributes to the ongoing European debate on whole-life-cycle carbon assessment while clarifying its novelty as a geometry-based, product-stage method that can be scaled and adapted to different contexts. The proposed simplified, geometry-oriented approach to estimating embodied impacts (A1–A3) with shape factor-based normalisation enables a fair comparison of buildings with different geometries at the concept stage.

Achieving carbon neutrality by 2050 is one of the European Union’s key priorities. Yet, the attitude of numerous politicians, of the professional community, and of society in general towards the threat posed by climate change is ambivalent. Arguments are frequently heard about the transition to a low-carbon economy that will be very costly, with increased unemployment, and that in reality climate change may not even be that severe. Added to this, there are human rights and freedoms, and in the case of architects and designers, the right to freedom of creation, to choice of materials, etc. The present article seeks to show that the issue of sustainable architecture and construction is not a whim, but an absolute necessity, and that true freedom lies in recognizing this fact and adapting our actions accordingly. However, even if we have the good intentions to adapt the needed actions, there is still the question of how to react in the right way, without causing myriad unwanted side-effects or being completely counterproductive. As there is not yet any comprehensive account of the history of energy-efficient and sustainable building and architecture, this paper has attempted to give a brief overview of developments in this field from a Central European perspective. Furthermore, the aim was to point out some conceptual mistakes that have been made in the past and that should be avoided.

This paper investigates the conditions under which moisture condensation occurs on the surface of the bottom chord of a steel truss at the ceiling level of the attic hall of a historical building in Poltava, Ukraine. Moisture condensation on steel structural elements leads to steel corrosion and a decrease in the thickness of structural elements. As a result, the load-bearing capacity of both individual elements and the entire structure can be reduced. This paper describes how different parameters affect the process of condensate formation on the surface of steel bottom chord angles of the truss. Three parameters are investigated: the filling of the gap between the angles and precast reinforced concrete elements resting on the lower flange of the angles with thermal insulation; the filling of the gap between the two angles of the bottom chord of the truss with thermal insulation; and the possibility of detachment of the different sizes of finishing layer from the bottom flange surface of the angles. Verification calculations of the possibility of condensation forming on the metal surfaces of the bottom chord of trusses were also performed for the developed design solutions for restoration.