One Take #16 - The False Promise of Indoor Comfort: Why Current Building Standards May Be Harming Our Health

What if the very standards designed to keep us comfortable in buildings are actually making us unhealthy? This provocative question lies at the heart of groundbreaking research from Delft University of Technology.

It challenges the fundamental assumptions that have guided building science for decades. Even when our buildings meet all current standards for temperature, lighting, acoustics, and air quality—and even when occupants report feeling comfortable—the fact remains that spending 90% of our lives indoors may be harming our health.

The problem stems from our reliance on simplistic "single dose-response" models that isolate individual stressors like CO2 or temperature. These models fail on three fronts: they prioritise preventing short-term discomfort over promoting long-term health, they ignore how environmental factors interact with each other, and they're based on an "average person" who doesn't actually exist. The thermal comfort example is particularly striking—our pursuit of thermally neutral environments might be contributing to obesity by never challenging our bodies to regulate their own temperature.

Professor Bluyssen advocates for a shift toward "situation modeling"—a holistic approach that considers the entire context of environment, individual, and activity. Her field studies reveal just how diverse our environmental preferences are, even within shared spaces like classrooms. When a teacher opens a window, it might please some students while making others miserable by letting in traffic noise.

The path forward isn't about finding magic numbers for ventilation rates or perfect temperatures. It's about creating flexible, adaptive spaces that accommodate our diverse needs and give us greater control over our environments. Though this approach is more complex, it represents our best chance at designing indoor spaces that truly support human health and wellbeing rather than merely preventing immediate discomfort.

The need to go beyond the comfort-based dose-related indicators in our
IEQ-guidelines

Chapters

• 0:00 Welcome to One Take
• 0:37 Challenging Indoor Environment Standards
• 1:32 Three Flaws in Current Standards
• 4:31 Situation Modeling: A New Approach
• 6:23 Implications for Building Design
• 8:07 Concluding Thoughts and Thanks

Transcript

Speaker 1: 0:14

welcome back to air quality matters. And one take one take, my take on a paper or report on indoor air quality, ventilation and the built environment. One take in that it's well in one take and tries to summarize for you a scientific perspective on something interesting in well, usually 10 minutes or less, because who has the time to read all these amazing documents? Right? This week we're looking at a paper that throws down a real gauntlet. It's a fundamental challenge to the way we've thought about and regulated our indoor environments for decades. The paper is titled the Need to Go Beyond the Comfort-Based, dose-related Indicators in Our Indoor Environmental Quality Guidelines, and it's by Professor Philomena Blyson from Delft University of Technology. The core argument is provocative but simple. Even when our buildings comply with all the current standards for temperature, light, acoustics and air quality, and even when people say they feel comfortable, staying indoors for 90% of our lives is still not good for our health. She's essentially arguing that our entire regulatory framework is built on a flawed foundation and we need a radical rethink. So let's get into it.

Speaker 1: 1:36

The paper starts by laying out the central problem Our guidelines for indoor environmental quality. Things like setting a minimum ventilation rate, a target temperature range or a maximum noise level are almost all based on what she calls single dose response relationships. What does that mean? Stressor at a time, say co2, and working out a dose, a concentration level that an average person can tolerate before they start to feel uncomfortable or their performance drops. We do this in isolation for temperature, for lighting, for noise and from this we've built our standards.

Speaker 1: 2:22

But, she argues, this approach is flawed for three big reasons. First, these standards are designed to prevent short-term discomfort, not promote long-term health. The paper uses a brilliant example thermal comfort. Our standards are all about achieving a thermally neutral state where our bodies don't have to work to stay warm or cool. But she points to studies suggesting that this constant thermal neutrality might be contributing to increase obesity, because our bodies are never challenged to burn energy to regulate their own temperature. So what we've defined as comfort might not actually be healthy in the long run. Second, the single dose model completely ignores the fact that in the real world we're never exposed to just one stressor at a time. We're exposed to a complex cocktail of thermal, air quality, lighting and acoustic conditions, all interacting with each other. The paper highlights research on cross-modal effects how, for example, being exposed to annoying traffic noise can make you perceive the air quality is worse, even if nothing about the air quality has actually changed. Our brains don't experience these things in neat, separate boxes. They integrate them into a single holistic experience. Our standards and guidelines, however, still treat them as completely separate issues.

Speaker 1: 3:54

And third, and this is the most important part, the model is based on a concept of an average person, but there's no such thing. We all know that, right. We're all different. Our needs and preferences change depending on our age, our health and our gender, and even what we're doing at any given moment. The right lighting for concentrating at work is different from the right lighting for a relaxing break. A temperature that's perfect for one person might be too cold for another person at a desk.

Speaker 1: 4:26

So, having laid out why the old model is broken, professor blyson proposes a new model. Instead of effect modeling based on single dose, she advocates for a situation modeling. This is a much more holistic approach. It says we need to stop thinking about isolated stresses and start thinking about the entire situation, the combination of the environment, the person and the activity they are performing. So, instead of just measuring co2 and temperature, for example, this model brings in what she calls building relating indicators like is there an operable window, and occupant related indicators like are are there or is this person's individual preferences and needs taken into account. The goal is to move beyond generic, one sizesize-fits-all standards and towards an understanding that allows for more personalized and adaptive environments.

Speaker 1: 5:23

The paper then presents the results from a whole series of field studies in offices, homes, schools and hospitals that tried to put this new model into practice. They used detailed questionnaires to cluster people into different profiles based on their preferences. For example, in a study of school children, they found distinct groups. Some were primarily concerned with noise, others with temperature, others with light and some weren't particularly concerned about anything. And the crucial finding was that in any given classroom, all of these profiles were present. So when a teacher opens a window, it might make the thermally concerned child happy, but it might make the noise concerned child more miserable by letting traffic noise sounds in.

Speaker 1: 6:14

This is the fundamental challenge of managing shared indoor spaces, and it's something our current uniform standards completely fail to address. So to wrap this up, what's my take on this? This is really thought-provoking piece of work. It's a call to move beyond the simplistic, reductionist approach that has dominated building science for a century is an argument for embracing complexity. The idea that comfort is not necessarily healthy is a powerful and challenging one that should make us all stop and think.

Speaker 1: 6:51

Now, does the paper give us a new, ready-to-use set of guidelines to replace the old ones? No, it doesn't, and it admits that this new situation model is far more complex and difficult to implement. But that's not the point. The point is to change our way of thinking, challenge our way of thinking. It's a plea to stop looking for a single magical number for the right ventilation rate or the perfect temperature. Instead, we need to focus on understanding the interactions between stressors and, most importantly, on understanding the diverse needs and preferences of the actual human beings inside our buildings. It suggests that the future of healthy buildings might lie less in rigid standards and more in creative, flexible, adaptive and personalized environments that give occupants a greater sense of control. This is a much harder task, but, as this paper argues so persuasively, it's one that we need to take on if we're serious about creating indoor environments that don't just avoid discomfort but genuinely promote long-term health and well-being.

Speaker 1: 8:07

Thanks for listening. I hope you enjoyed this week's episode of one take. As always, these podcasts are not possible without our partners safe traces and input. So thank you to them. See you again next week.