Conference Agenda

The increasing impacts of climate change pose significant challenges to the effectiveness of energy performance regulations for buildings. This study investigates the resilience of Wallonia’s Performance Energy Building (EPB) standards in light of contemporary climate realities, as well as using weather projections that account for the SSP585 scenario for the end of the century. Focusing on a comparative analysis between historical residential buildings and those compliant with current EPB regulations, the research aims to assess how well these standards withstand the projected climate scenarios outlined by the Intergovernmental Panel on Climate Change (IPCC). Through a detailed evaluation of thermal performance, energy efficiency, and adaptability to extreme weather conditions, this paper seeks to highlight potential shortcomings and areas for improvement in Wallonia's building regulations. Ultimately, the findings will contribute to the discourse on enhancing building resilience, ensuring that energy standards not only address present needs but also anticipate future climate challenges.

During the summer of 2018, northern Europe endured a heat wave rarely seen before. The heat wave was exceptional, with high temperatures and long duration, leading to 700 reported heat-related deaths in Sweden. Such extreme events are projected to increase even more in the future, yet the extent of overheating occurrence in different buildings and dwellings in Sweden is unknown. Currently, the Public Health Agency of Sweden recommends an upper threshold of 26°C (78.8°F) for sensitive occupants and that nighttime temperatures above the same threshold should be avoided for all occupants. However, it is not established how these recommendations should be used for the evaluation of overheating occurence in the building stock.

Over the last few years, several overheating assessment methods have been developed worldwide to address the growing overheating risk. The focus remains primarily on preventive measures and methods that apply to simulation studies. Although these methods can be applied to monitored data, they are not usually constructed with that in focus. The aim of this paper is,

therefore, to compare how two overheating assessment approaches apply to large-scale monitoring datasets and identify their respective strengths, weaknesses, and limitations. The approaches examined are exceedance over thresholds and the overheating assessment method TM59 by CIBSE. Hourly indoor air temperature measurements from 25,788 apartments in Gothenburg from 2018 and 2024 are used in the analysis. The results demonstrate that the approaches studied are highly sensitive to threshold selection, whether static or adaptive, and the method followed. The analysis also highlights the uncertainty in selecting assessment period and occupancy schedule when dealing with measured data. There is a need for benchmarking methods specifically tailored to big data overheating analysis, which can provide reliable indicators of both the extent and patterns of overheating in existing building stocks.

Climate change and urban heat island effects are increasing the frequency and intensity of extreme urban heatwaves, highlighting the critical need for innovative, resilient, and sustainable cooling strategies. Urban trees have consistently been identified as effective solutions due to their cooling potential, yet guidance on their deployment remains limited, particularly in the Canadian continental climate. This study investigates the role of increased tree canopy coverage in enhancing thermal resilience within a neighbourhood in London (ON), Canada. A validated microclimate model and archetype building simulations are employed to evaluate the effects of tree canopy coverage on outdoor and indoor thermal stress. Tree canopy coverage is increased from a baseline of 6% to 30%, in alignment with Nature Canada’s recommendations, through two deployment strategies: 1) a straightforward approach targeting outdoor temperature hotspots, and 2) a building-focused approach aimed at reducing indoor heat stress. Building thermal resilience is evaluated accounting for microclimate impact, heat stress intensity and exposure time. Results show that increased tree canopy coverage leads to thermal benefits. Both strategies achieved similar maximum reductions in building surrounding outdoor temperature by up to 4.0 ºC and Standard Effective Temperature (SET) by up to 6.9 ºC at 3 PM. Indoor thermal stress also decreased significantly under both deployment strategies. Furthermore, grown tress demonstrated cooling effects compared to young trees, reducing outdoor and indoor temperature by an additional 1.5 ºC and 1.7 ºC, respectively. While both strategies were effective, the indoor based strategy provides a more uniform distribution of building thermal resilience. This distinction, however, diminished at higher canopy coverage by 30%. These findings suggest that increasing tree canopy coverage to 30% by targeting outdoor temperature hotspots, offers a practical and effective strategy to enhance thermal resilience in urban communities.

The International Energy Agency (IEA) predicted that in the coming years, the frequency and intensity of heat waves will increase significantly. This rise will be matched by a greater need for air conditioning by populations, while the performances of current methods are expected to reach their limits. It is in this context of a need for a more resilient technology that this study takes place. The SWAC technology (Sea Water Air Conditioning) uses deep seawater to cool buildings. There are three operational SWAC systems in French Polynesia, including two that are instrumented for performance monitoring. Using the installation in Tetiaroa as a case study, a SWAC-with-building-integrated model was developed in EnergyPlus to replicate its behavior. This led to an accurate depiction of the performance compared to measured results.

The study presented here explores the integration of SWAC systems into standardized building models to evaluate their potential for energy resilience across various regions and climates. Our approach follows the recommendation of Annex 80 of the IEA by integrating this original SWAC model with two innovative frameworks: (1) prototype building models developed by the U.S. Department of Energy (DOE), representing various buildings (offices, hotels, hospitals), combined with climate files produced by Annex 80 that include projections of future climates (2050–2100) in numerous regions; and (2) a global cartography of SWAC feasibility that accounts for geographic and bathymetric variations in pipe length requirements.

By combining these frameworks, the study bridges a critical gap by adapting a localized SWAC model with standardized building prototypes and adjusting sizing and operational parameters—such as pipe length—to regional conditions. The results underscore SWAC’s significant potential as a sustainable cooling solution, demonstrating its ability to reduce energy consumption while ensuring thermal comfort in a global warming context.

With the rising extreme weather events due to climate change, heatwaves have become a critical public health concern. During the 2021 Vancouver heatwave, over 600 heat-related deaths were recorded, many of which occurred in multi-unit residential buildings (MURBs) and primarily affected older adults without access to mechanical cooling. This study investigates the thermal resilience of MURBs under such conditions.

The study’s objectives include identifying the most heat-vulnerable zones within MURBs, understanding the rate of indoor temperature escalation, and determining when spaces become thermally unsafe. To mitigate the impact of extreme heat, we evaluated passive cooling strategies using energy simulation, distinguishing between tenant-implemented methods (e.g., natural ventilation, fans) and owner-led interventions (e.g., cool walls, cool roofs), which often require resources and planning beyond tenants' control.

Using a spatiotemporal approach, key performance indicators (KPIs) such as Indoor Overheating Degree (IOD), Exceedance Hours (EH), Standard Effective Temperature (SET), and Heat Index (HI) were applied to assess overheating during the heatwave period. Both tenant and owner strategies increased comfort hours, but owner strategies were more effective at reducing overheating hours, particularly on the top floors. Combined tenant and owner strategies proved most effective, further increasing comfort hours and significantly reducing overheating hours. Additionally, we found that different KPIs varied in their effectiveness at detecting unsafe conditions. Notably, SET-based KPIs were less effective at detecting overheating during the heatwave and were more sensitive to physiological factors, such as air movement, metabolic rate and clothing.

These findings underscore the importance of selecting appropriate KPIs that align with specific resilience goals, as different KPIs provide distinct insights into overheating, comfort, and health impacts. Furthermore, the interventions necessary to improve thermal safety often exceed tenant capabilities, highlighting the need for policy-driven, owner-led retrofits in MURBs to enhance heat resilience in urban housing and preparedness for future heatwave events.