Architects from the University of Sheffield studied how natural light in living spaces influences mood. The findings, published in Building and Environment, show that higher levels of daylight can boost happiness, while certain materials used in walls can dampen it. These insights add nuance to what many people already sense about how a room makes them feel and point to practical steps for homes and workplaces alike.
In this exploration, researchers sought to determine which features of interior design most strongly affect emotions. A diverse group of 750 participants evaluated 25 room designs that varied in natural light across living rooms, kitchens, bedrooms, and bathrooms. Each room presented different patterns of window placement and sizes, with some designs oriented to face north and others toward the south. Participants were asked to rate their immediate mood responses as they viewed each space.
The results were telling. People tended to feel happiest in rooms where windows covered about 40 percent of the wall area. This balance of daylight seemed to optimize visibility while avoiding glare. The materials used on wall surfaces also mattered. Plaster and timber wall finishes were linked to more positive mood responses, whereas visible brickwork tended to produce lower happiness ratings. One plausible explanation is that different materials interact with light by absorbing and reflecting it in unique ways, shaping the overall atmosphere of a room.
While the precise mechanisms behind these mood changes require further study, a body of evidence indicates that light exposure can elevate serotonin levels, sometimes called the body’s happiness hormone. Light therapy is a recognized treatment for seasonal affective issues, underscoring the strong connection between light and mood. In a world where people spend more time at home for work and leisure, these findings have practical implications for designers, builders, and city planners. The researchers suggest prioritizing indoor daylight in new construction and renovations to foster healthier, more uplifting environments.
This line of work supports a broader view of the built environment as a contributor to well-being. By incorporating daylight-rich layouts and thoughtful wall finishes, homes can become sources of daily emotional stability. The study underscores the value of daylight-aware design as a standard practice for residential development, encouraging stakeholders to consider light as a core aspect of architectural quality and community health. Researchers emphasize that simple design choices—how much of the wall is windowed, and what materials cover those walls—can meaningfully affect how people feel when they are at home.
In summary, optimizing natural light and selecting appropriate wall materials are practical, impactful strategies for improving mood inside living spaces. The University of Sheffield work adds to a growing understanding of how the indoor environment shapes daily emotions, offering guidance for homeowners and professionals aiming to create brighter, more welcoming interiors. The findings invite cities and developers to rethink typical housing layouts, placing daylight and material choice at the forefront of human-centered design.