It is estimated that about 70% of a person’s total life span is indoor life, and the health effects of different building types have just begun to be the subject of investigation. Modern residential architecture has not only been public concern due to its beauty and functional properties, but has also become a health issue by being recognized as a vital part of the general health of the population, whose impact could be compared with that of diet and physical activity in terms of the combined effect.

The Circadian Architecture Crisis

Light coming from the sun is considered the main and the most important source of support for the production and elimination of hormones and the immune system as well as practically all human biological processes. Nevertheless, a study carried out by Lighting Research Center revealed that office staff get merely about 58 minutes of sun exposure a day as opposed to the 2–3 hours needed for the proper functioning of the circadian rhythm. The residential sector is not free from the problem; pre-1990 houses, on average, have only a 12% window-to-wall ratio, whereas current buildings are suggested to have a ratio of 25–30% to be called good in terms of daylight penetration.

If one seeks to see through a different lens the light’s medical effects and the world’s views on the matter, The Netherlands would be an ideal spot. The minimum daylight factor in all habitable rooms that was part of the 2012 building code revisions was the reason why longitudinal research was carried out that eventually had 3,400 people following up and reporting the decline of their sleep disturbances by 23% and the rise of their winter mood stability scores by 19%. The projects involved were not lofty ones; rather they were regular social housing estates where architecture intervention was able to bring health benefits to different socioeconomic groups equally.

Spatial Configuration and Behavioral Patterns

The way the floor plan is shaped influences the habits of the inhabitants so subtly that they often do not realize it. Open-plan housing, which occupied about 68% of the new construction market share by 2023, has a big influence on family dynamics. A study from the Space Syntax Laboratory at the University College London shows that open-floor plans lead to a 41% increase in social interactions, but also result in a 32% decrease in concentration for tasks that need it, due to noise and sight distractions.

The tradeoffs made by the pandemic were very clear and dramatic. Housing units without a specific area set aside for work-from-home were found to have 47% higher stress levels compared to the ones with segregation of space, according to data from the International WELL Building Institute that was collected from 14 countries. The “Zoom room” is no longer a luxury but has become a building response to the working style of 35% global knowledge workers that has been developed.

In comparison, Japanese housing can serve as an exemplary case. The habitual spatial fluidity of the sliding fusuma panels allows each room to have a different function while at the same time keeping the psychological boundaries. The application of this principle in the case of modern 45-square-meter apartments in Tokyo, where spatial flexibility is considered to have a greater impact on perceived spaciousness than the actual size of the apartment, is a revelation with far-reaching consequences for crowded cities.

Air Quality’s Significance

Indoor air quality is what architects do not pay attention to as the health care limit of their buildings. The EPA mentions that indoor air pollutants in most cases are 2 to 5 times dirtier than those outdoors, and sometimes, due to certain activities, the indoor air pollutants can be even 100 times more polluted than outdoor air. Building scientists are labeling the modern airtight building, which is energy-efficient and having filth in airflow, as a “sick building syndrome”.

The German Passive House standard is one of the potential solutions to this problem as it has constant mechanical ventilation with heat recovery installed to allow the air exchange of 0.6 per hour while at the same time providing excellent thermal insulation. A health research carried out for 10 years on 8,000 Passive House residents revealed 40% and 52% less incidence of respiratory ailments and asthma attacks respectively as compared to the conventional housing cohorts. The initial construction costs of 8–12% more led to savings in healthcare of around €3,400 per household annually.

Materials used have the opposite effect to that of the given. The VOCs from synthetic finishes, glues, and other treatments will still be off-gassing long after construction — sometimes even years. The trend of low-VOC materials is much more than just a ‘green-washing’ effort. Considering the fact that formaldehyde at the levels common in new constructions (0.1 to 0.5 ppm) has been shown to reduce cognitive performance in standard testing, this trend cannot be simply put down to environmental theater.

Mental Strain from Environmental Noise

Infiltration of sound is the least considered health factor in architecture. Noise is recognized by WHO as the second most important environmental health issue after air quality. The cardiovascular disease risk goes up by 8% for every 10 decibel rise if the residential noise level exceeds 55 decibels — this happens, for instance, in urban apartments with insufficient acoustic insulation.

Lightweight constructions adopted by builders are a cause of noise disturbance in rooms. Their technical acoustics are still leaving a lot to be desired, as minimum sound insulation requirements in building codes are letting the impact noise reach up to 65 dB, which is above the level where sleep is disrupted and cortisol, the stress hormone, is increased in the body. Under the new regulations, which came into effect in 2020, the necessary acoustic performance in South Korea for multi-family housing is now 43 dB for impact noise isolation. The first compliance data indicates such a remarkable reduction of neighbor disputes (31%) and such an improvement in sleep quality (as per residents’ reports).

Thermal Experience and Productivity

In fact, temperature can impact cognition significantly more than it is usually thought. The study done by Lawrence Berkeley National Laboratory, has let us know that cognitive performance at its best is between 21 °C and 22 °C, hence each degree of temperature deviation would be accompanied by a 2% productivity loss. However, traditional HVAC systems still work in such a way that the temperatures in single rooms differ by around 3–5 °C, meaning that at different times, 30–40% of the workforce would be feeling thermally uncomfortable.

Radiant heating and cooling systems are in the building construction of which the environmental benefits and the reduction of energy consumption are similar. In Scandinavia, Energy savings in occupant studies showed an increase of 18% in concentration and a decrease of 24% in fatigue. Not only the mechanical systems have to cope with such architectural implications — thermal mass, insulation placement, and window performance together determine thermal comfort in the first place before the HVAC capacity.

Recommendations

Throughout the study, the evidence supported the need for the architectural standards to consider human health as the primary concern along with energy performance and structural safety. The Dutch case is to be replicated and a minimum of 2.0–3.0% daylight factors are to be specified for all living spaces, as this will enable the policymakers to do so. The building codes shall also include the performance standards for acoustics that would treat sound as a health factor rather than just a comfort preference.

Ventilation should be based on actual occupancy and activity patterns rather than outdated minimum standards. The new construction requirement for continuous mechanical ventilation as stated in California’s Title 24 is the least that can be done for air quality management.

Tax deductions should be available for renovations that promote health, like replacing windows, upgrading ventilation, and improving acoustics. When all these interventions are considered in terms of health and productivity losses, as well as healthcare costs, they lead to public health returns that are significantly higher than the costs involved.

Professional licensing should be such that architects must have knowledge in the field of evidence-based health outcomes, not only in aesthetics or structure. Architecture has a direct impact on biology, thus it is very much time that the building standards mirror this reality.