For some time now, we have been working closely with our partners JLP, COEX, and LLA on the ambitious expansion and major renovation project of the Institut national de psychiatrie légale Philippe-Pinel. The challenge is significant: transforming a building inaugurated in 1970 into an exemplary and innovative clinical and research environment. At the time, forensic psychiatry was an emerging field, and the government was urgently seeking new methods to treat and manage complex psychiatric cases.
Today, a growing body of research points to the same conclusion: architecture and design have a real impact on the physical and mental health of occupants. These impacts are even more significant when the buildings we design serve vulnerable populations such as older adults, young children, people with cognitive impairments, or individuals living with mental health challenges.
Below are a few examples of elements that shape a building’s interior environment and their effects on occupants’ mental health.
The quality and quantity of natural light
Studies have shown that exposure to natural light can improve mood and reduce symptoms of depression. It can help lower levels of cortisol, the body’s stress hormone. In addition, natural light stimulates the production of serotonin, which regulates mood and promotes a sense of well-being. Daylight is also a key regulator of circadian rhythms, which govern the sleep–wake cycle and improve sleep quality, an essential factor for both physical and mental health. Finally, natural light supports the production of vitamin D, which plays an important role in mood regulation and the prevention of depression.
Spatial layout and ergonomics
Thoughtful, ergonomic design helps create spaces that are pleasant and easy to use. Open, well-lit environments encourage social interaction and foster interpersonal relationships, which can have a positive effect on mental health.
Thoughtful use of color
Colors influence human mood and behavior. Bright, stimulating colors can be beneficial in spaces where energy and activity are required, while calmer, more soothing tones are better suited to areas intended for relaxation and rest.
The nature of materials used
The use of natural materials can positively influence occupants’ mental health by creating environments that feel more pleasant and calming. Materials such as wood, stone, bamboo, terracotta, and other organic elements help establish a warm and comfortable atmosphere that can reduce stress and promote relaxation. They can also improve indoor air quality by limiting the presence of toxic chemicals. More broadly, natural materials help reduce environmental stress by strengthening the connection to nature and fostering a sense of belonging to the natural world. This connection can help alleviate anxiety and stress associated with modern urban life, where people often spend extended periods in artificial environments disconnected from nature.
Acoustic performance and sound quality
Poor acoustics can lead to elevated levels of stress and distraction. Well-designed, acoustically controlled spaces help reduce noise levels and improve concentration, contributing positively to mental well-being.
Beyond functionality, performance, and technical requirements, the choices made by architects and designers can directly support the maintenance and improvement of occupants’ physical and mental health. In a project such as the Philippe-Pinel National Institute of Forensic Psychiatry, every design decision carries particular weight, as it directly contributes to patients’ well-being, their recovery, their reintegration into society, and ultimately their return to a healthier and more fulfilling life