What is a Comfortable Home?

Comfort is probably one of the most important and overutilized concepts in housing. All kinds of professionals—Architects, Building Scientists, Builders, Engineers, Real Estate Agents, and developers, Architectural product manufacturers, and others—often claim that whatever they offer “is comfortable” and/or that “it makes your home more comfortable”. They very often do it with genuinely good intentions, but some people just exploit the fact that the word “comfort” has a good connotation while being vague enough to prevent any binding commitment. Building Science, however, has no choice but to deal with this concept. After all, buildings are supposed to be comfortable and thus evaluating whether a certain design decision improved comfort requires a more concrete definition of what a comfortable building is.

In order to operationalize the concept of comfort, Building Scientists have developed the concept of Indoor Environmental Quality. This concept suggests that a room or building will be more comfortable if it offers Thermal, Acoustic and Visual Comfort, and good Air Quality. The way to evaluate Indoor Environmental Quality is by using quantitative data about factors such as temperature, noise, light, relative humidity and pollutants in the air to estimate how acceptable the current conditions are. While this makes sense at first sight, this approach can be limiting. For instance, this concept provides no explanation as to why we do not feel uncomfortable when going inside of a giant fridge to get some beer, or why tropical places are so popular and "relaxing", even if fridges are too cold and the tropic is (for many people) too hot. It also does not explain why people with more control of their environment seem to be more tolerant of discomfort. The model of the Feeling of Comfort—from which the Atlas of Comfort was derived—can help explain these situations.

The model of the Feeling of Comfort defines Comfort as the result of the meaning people give to situations. In other words, people will decide—consciously or unconsciously—whether a situation is comfortable based on multiple factors. This judgement has three components.

First, people will judge the here and now through Perceptions. This is relatively straightforward. For instance, people check whether they feel cold or hot, or whether a room is noisy or quiet. Some Perceptions have been widely studied within the context of Indoor Environmental Quality. However, virtually all of them can be relatively easily linked to people’s physiology. For instance, Glare is in peoples eyes; Thermal Sensation, in their skin; Loudness, in their ears; and Air Quality, in their noses or lungs. This is limiting because people often feel more or less comfortable for reasons located outside of their physiology and the physics of the environment. For instance, whether a space looks dirty or clean, whether they feel a connection with the exterior world, whether they think they are bothering their neighbours, or whether they think their families are feeling fine. Hence the importance of not only overemphasizing the physical and physiological components of Comfort.

The second appraisal people make reflects an awareness of the future. Namely, they will infer some Expected Outcomes that will influence their Feeling of Comfort. This is not considered by the concept of Indoor Environmental Quality at all, and yet it can be crucially important. For example, Thermal Comfort studies—as part of Indoor Environmental Quality—suggest that being exposed to extremely hot conditions is uncomfortable. What Thermal Comfort studies do not mention, however, is that the same temperature can result in different levels of comfort depending on the situation. For instance, being exposed to extremely hot conditions in a laboratory experiment is much less dramatic than being exposed to the same temperature during a real heatwave. Namely, while in the first case we know that the experiment will last one or two hours and that they will keep us safe, it is kind of hard for us to know how much an actual heatwave will last and thus we might panic. Furthermore, experiencing a heatwave while living by yourself might be very different to experiencing one when being responsible for others.

Finally, the third appraisal people make reflects how they always put the current situation in a broader context, checking the Trade-Offs they have made. In other words, people know that improving one aspect of Indoor Environmental Quality can deteriorate other aspects of their lives and thus studying or focusing on one element in isolation can be misleading. For example, people often need to choose between opening the windows to cool down their home or keeping them closed to avoid the noise and thus people's operation of windows cannot be explained based on temperature only. Moreover, some people mentioned how they keep the windows closed because of safety concerns, even if they would have rather keep them open, suggesting that the operation of windows cannot be explained exclusively based on physical variables. Contrary to this, Building Science has generally (not always) kept these domains separated. In fact, building simulation tools generally focus on only one or two of these things. From my perspective, we should never forget that people do not separate between Indoor Environmental Quality domains and that they do not separate Indoor Environmental Quality from the rest of their lives.

Based on these three appraisals, a comfortable home needs to comply with three requirements. First, it needs to offer a good here and now environment (i.e., satisfying Perceptions); second, it needs to suggest to people that their future will keep being comfortable (i.e., the Expected Outcomes must look good); and third, it needs to do all this at a low personal cost (i.e., minimal Trade-Offs). The result of this is a home that maximizes people’s freedom and wellbeing.

I want to conclude by emphasizing that the model of Feeling of Comfort and the Atlas of Comfort do not just allow visualizing comfort data, but also reflect a new understanding of the concept altogether. This has implications for research, public policy, and practice. Very soon I will write a blog article on how can the Atlas be used in different scenarios, but they will just be examples. After all, when you change the way you understand something, a huge number of changes can follow.