Conference Agenda

Managing the indoor microbiome is an underutilized dimension of Indoor Environmental Quality (IEQ), holding significant potential to optimize occupant health, well-being, and building performance. This paper discusses the current understanding of a healthy building microbiome and identifies critical gaps in existing research that must be addressed in order to integrate the building microbiome into IEQ performance metrics. It explores the interplay between indoor and outdoor air quality, microbial communities, occupant health, and configurable building factors such as natural versus mechanical ventilation, air cleaning technologies, humidity control, surface properties of materials, and space utilization. Additionally, it explores the influences of cultural practices, socioeconomic status, and proximity to outdoor air hazards on microbial exposures and health outcomes, providing an important opportunity to decrease environmental inequities.

While optimizing IEQ for occupant health, productivity, and building performance is increasingly incorporated into sustainability goals and climate resilience, understanding the role of indoor microbiomes is lacking. We see a future of building design for healthy building microbiomes using microbial sampling tools, health data, real-time smart sensor technologies, and machine learning models. This could lead to transformative IEQ policies and best practices, fostering buildings that simultaneously support beneficial microbes, mitigate harmful pathogens, and thus enhance occupant health. This framing paper’s intended audience includes researchers, practitioners, and policymakers.

The health risks of heat exposure are well established, particularly when temperatures exceed minimum mortality thresholds (MMTs). While most epidemiological research focuses on outdoor temperatures, this study adapts a burden-of-disease framework to estimate acute health impacts from indoor heat exposure using Disability-Adjusted Life Years (DALYs). We developed a new harm intensity metric to quantify DALYs per degree of daily indoor temperature exceedance above the MMT. The method combines risk estimates, incidence rates, damage factors, and indoor temperature profiles. We applied this approach to monitored social housing in Bolzano, Italy, during summer 2024. Four scenarios were analysed, varying by age group (all ages & 65+) and two MMTs (24.4°C & 28°C ). Inputs were based on meta-analyses of temperature-mortality associations and Global Burden of Disease data. Estimated impacts ranged from 0.005 to 0.022 DALYs/day for a population of 791, with higher burdens in older adults and at lower thresholds. The highest burden (0.022 DALYs/day) was observed in the 65+ group using the 24.4°C threshold . This framework supports the integration of health metrics into building and housing assessments. By expressing harm in DALYs, it enables comparison with other environmental risks and offers a foundation for future research and policy development.

In Ventilation Information Paper VIP 38 of March 2018, AIVC defines smart ventilation as “process to continually adjust the ventilation system in time, and optionally by location, to provide the desired Indoor Air Quality (IAQ) benefits while minimizing energy consumption, utility bills and other non-IAQ costs (such as thermal discomfort or noise).” While these objectives are clear and the benefits of smart ventilation are now obvious, the assessment of the solutions is still a matter of debate. The assessment of smart ventilation solutions faces significant challenges due to the lack of standardized metrics and the variability of indices used, which depend on priorities such as occupant health, indoor comfort, or building preservation. This study, based on literature review of IAQ indices and numerical simulations, highlights this divergence and their impact for system assessment.

Several smart strategies for 3 different ventilation systems (Mechanical Heat Recovery Ventilation, MHRV, Mechanical Extract Ventilation, MEV, and Positive Input Ventilation, PIV) were simulated in a single dwelling. The number of occupants and attendance times are fixed and 1 week scenario and 1 weekend scenario are modeled for 4 weather conditions typical of each season. Concentrations of four pollutants (Humidity, CO2, VOCt and PM2.5) were analyzed using two IAQ indices from the literature. For each ventilation system, the results of the different smart strategies were compared against a reference strategy.

The results show that IAQ criteria related to health, comfort and prevention of building pathologies do not always coincide.

Airborne contaminants pose health risks in office environments, where adults spend a significant portion of their day. We integrated data from global systematic reviews of contaminant sampling in office environments and applied a harm-based methodology using the Disability-Adjusted Life Year (DALY) metric. This approach quantifies the health impact of indoor air contaminants in offices. By examining the "cost per DALY" from literature on global north countries, we calculated the annual monetary costs due to exposure to selected priority contaminants in office buildings per 100,000 people. Results indicate that particulate matter (PM) is a major contributor, accounting for 62% of total costs. These findings underscore the importance of effective control strategies to reduce contaminant exposure. If control strategy costs for each contaminant are lower than the monetary costs associated to the harm (as DALYs) they cause, these strategies may serve as cost-effective interventions in offices. This study contributes to the ste of the art about the value of DALY-based harm metrics in guiding cost-effective interventions and improving indoor air quality in office buildings. Further research should investigate the broader implications of these findings and develop targeted interventions to enhance workplace health and safety in offices.