Tadeusz Kuczyński

Buildings are increasingly expected to operate as flexible components of low-carbon energy systems while maintaining thermal resilience under disturbances. This study investigates the impact of slab–ground coupling on indoor temperature dynamics during heating interruptions through a full-scale experimental comparison of two geometrically identical residential buildings with different under-slab boundary conditions, supported by a calibrated reduced-order dynamic model. The results reveal a multi-scale thermal response. In the short term (6–12 h), the ground-coupled configuration exhibits faster initial cooling and a 3–4% reduction in thermal retention. However, after approximately 24–48 h, a crossover occurs, after which the ground-coupled building maintains higher indoor temperatures. After six days, the temperature difference reaches up to 3.8 K, indicating enhanced thermal resilience. A simplified analytical expression is derived, showing that the initial cooling rate is governed by the indoor–ground temperature difference rather than total thermal capacity. This provides a mechanistic explanation of the observed crossover behaviour. In addition, the analysis separates the contributions of structural thermal mass and ground coupling, showing how their roles evolve from short-term envelope-dominated response to long-term ground-driven stabilisation. From an energy systems perspective, slab–ground coupling redistributes thermal storage across time scales, reducing short-horizon thermal accessibility while enhancing multi-day stability. This reveals a fundamental trade-off between demand-side flexibility and thermal resilience and highlights the importance of time-scale compatibility in building–energy system integration.

This paper examines building performance under extreme conditions by treating thermal resilience as a process-based and time-dependent property. Existing approaches remain fragmented: resentation, extreme event definition, resilience metrics, passive strategies, and energy systems are typically handled in isolation, leaving current methods with limited capacity to explain how buildings respond to prolonged disruptions such as heatwaves or power outages. The study offers a cross-domain synthesis of thermal resilience research, drawing together climate modelling, indoor thermal response, resilience metrics, passive design strategies, distributed energy systems, and regulatory constraints. Building on this synthesis, a trajectory-based framework is developed that links climate inputs, event definition, indoor thermal response, and performance metrics within a unified structure. This integration is extended into architectural design through a decision-oriented framework that interprets resilience as the outcome of a hierarchy of decisions structured by reversibility and operational dependence. Early design decisions define the constraints and the range of achievable performance within which subsequent optimisation occurs. Building performance emerges from the interaction of passive strategies and energy-supported systems under constrained conditions. The results establish that thermal resilience cannot be inferred from conventional indicators; it must be understood through the temporal evolution of indoor conditions. The proposed framework provides a consistent basis for linking resilience assessment with design decision-making, supporting a unified approach to resilience-oriented design.

Buildings are increasingly expected to operate as flexible components of low-carbon energy systems while maintaining thermal resilience under disturbances. This study investigates the impact of slab–ground coupling on indoor temperature dynamics during heating interruptions through a full-scale experimental comparison of two geometrically identical residential buildings with different under-slab boundary conditions, supported by a calibrated reduced-order dynamic model. The results reveal a multi-scale thermal response. In the short term (6–12 h), the ground-coupled configuration exhibits faster initial cooling and a 3–4% reduction in thermal retention. However, after approximately 24–48 h, a crossover occurs, after which the ground-coupled building maintains higher indoor temperatures. After six days, the temperature difference reaches up to 3.8 K, indicating enhanced thermal resilience. A simplified analytical expression is derived, showing that the initial cooling rate is governed by the indoor–ground temperature difference rather than total thermal capacity. This provides a mechanistic explanation of the observed crossover behaviour. In addition, the analysis separates the contributions of structural thermal mass and ground coupling, showing how their roles evolve from short-term envelope-dominated response to long-term ground-driven stabilisation. From an energy systems perspective, slab–ground coupling redistributes thermal storage across time scales, reducing short-horizon thermal accessibility while enhancing multi-day stability. This reveals a fundamental trade-off between demand-side flexibility and thermal resilience and highlights the importance of time-scale compatibility in building–energy system integration.

The integration of digital tools and environmental design methods is widely recognised as essential for sustainable architectural practice. However, their influence on early design decisions and lifecycle continuity remains limited. This study introduces the concept of integration readiness and operationalises it through the Integrated Environmental Design Framework (ILPP+), which links environmental methods to project phases, decision leverage, and organisational conditions. An exploratory survey of 37 architectural design offices in the Lower Silesian region of Poland was conducted to examine how BIM, life cycle assessment (LCA), passive strategies, performance-based analysis, and monitoring practices are embedded in design workflows. The analysis combines descriptive statistics with exploratory correlation analysis to identify relationships between selected integration dimensions. The results indicate uneven patterns of integration. Passive strategies and simulations show moderate coupling (ρ = 0.60), while weaker relationships between simulations and structured decision processes (ρ = 0.40) suggest that analytical tools are not consistently used as decision-support mechanisms. Similarly, BIM shows only partial integration with LCA (ρ = 0.41) and post-occupancy evaluation (ρ = 0.46), indicating limited lifecycle continuity within the analysed sample. These findings suggest that environmental integration may be constrained not by the availability of tools but by their positioning within decision processes and across project phases. The study highlights the importance of aligning analytical methods with high-leverage design stages and strengthening feedback loops between design and operation.

Life Cycle Assessment (LCA) is widely applied in building research and practice to quantify environmental impacts, yet its contribution to architectural decision-making remains limited. This paper argues that this limitation is not primarily methodological, but interpretative. LCA results are often presented independently of the hierarchy, timing, and reversibility of architectural decisions, obscuring where environmental responsibility can meaningfully be exercised. This study reframes LCA as an interpretative tool for understanding environmental responsibility across successive orders of architectural decision-making. A conceptual framework linking decision hierarchy, reversibility, and the temporal distribution of impacts is developed and examined through six deliberately selected case studies drawn from the peer-reviewed literature. The cases span early geometric and structural decisions, retrofit strategies, operational constraints, regulatory lock-in, and methodological assumptions. The analysis shows that the effectiveness of LCA varies systematically with decision order. At early design stages, LCA can inform highly irreversible choices and shape long-term environmental trajectories. At later stages, its role shifts toward exposing constrained trade-offs, residual conflicts, and limited remaining agency rather than enabling optimisation. By explicitly linking life-cycle impacts to decision hierarchy and time, this paper addresses a conceptual gap in current LCA research and supports more reflective architectural decision-making under uncertainty.

This study presents an empirical evaluation of winter heating performance in two full-scale single-storey residential buildings located in a temperate transitional climate in western Poland. The buildings, identical in geometry, layout, and insulation levels, differed in wall thermal mass and subfloor configuration. During the 2018/2019 heating season, the building with medium-weight masonry walls consumed 3.6% less heating energy than its lightweight timber-frame counterpart. In the following season, floor insulation was removed in the masonry building to enable direct ground coupling. While this led to a 12.2% increase in total energy use, the difference emerged only in the latter part of the winter. Continuous ground temperature monitoring confirmed that subsoil heat retained from summer acted as a thermal buffer, delaying the onset of increased losses. The actual energy penalty was substantially lower than predicted by standard calculation methods, indicating that steady-state models may overestimate seasonal ground-related losses. These findings highlight the dynamic nature of heat exchange between buildings and the ground and support the use of mass-based and soil-coupled envelope strategies as effective tools for improving seasonal energy efficiency and resilience in temperate climates increasingly affected by climate variability and power supply risks.

This study evaluates the passive thermal resilience of two full-scale residential buildings during natural summer heatwaves and blackout-like conditions in a temperate European climate. The buildings share identical geometry and ventilation but differ in envelope mass and ground coupling. Building B1 is a masonry structure with a slab-on-ground floor, while B2 is a lightweight timber-frame house. In 2019, B1 underwent a retrofit in which floor insulation was removed to enable direct subsoil heat exchange. Three complementary frameworks were applied: model IOD, AWD, OEF, the indicators AF and αIOD, and the health-based scenario rating HE, HIHH, and WBGT. Across all metrics, B1 demonstrated superior resilience, with overheating fully eliminated after ground coupling was introduced. B2, in contrast, remained vulnerable under both moderate and extreme events. The findings highlight the critical role of thermal mass and soil buffering in maintaining safe indoor conditions without active systems. Under certain circumstances, omitting under-slab insulation can improve summer resilience without significantly compromising winter performance. A companion life-cycle analysis confirms lower cumulative carbon emissions for B1 under all SSP scenarios to 2100. Passive ground coupling thus emerges as a low-cost, maintenance-free adaptation strategy with co-benefits for mitigation and occupant safety.