Windows, once simple openings in walls, have evolved through advancements in materials and technology, maximizing efficiency and expanding their role in architectural design. If Gothic architecture showcased marvelous glazing through towering stained glass windows, modern architecture shifted toward horizontal forms and fully glazed facades, transforming how daylight is integrated into spaces. However, relying solely on facade glazing presents a limitation—natural light is often confined to the building's perimeter, leaving central areas in shadow. Overhead openings, such as skylights and flat roof windows, overcome this challenge by channeling daylight deep into interior spaces, reducing reliance on artificial lighting.
Beyond their functional benefits, these openings serve as powerful aesthetic tools, sculpting interiors with light and shadow to define central spaces. This dynamic interplay enhances spatial perception, adding depth and visual interest. Additionally, roof windows contribute to natural ventilation, improving air circulation and overall indoor environmental quality. As a result, they have become essential elements in contemporary design, seamlessly merging efficiency with architectural expression. Below, we explore some key aspects to consider when specifying flat roof windows, highlighting their benefits and strategic applications for different projects.
1. Understanding the Importance of Natural Light for Spaces and Users
Beyond enhancing spaces and reducing dependence on artificial lighting, natural illumination plays a crucial role in user comfort and health by regulating circadian rhythms and improving the experience of performing household tasks. To ensure adequate lighting levels, specific regulations establish guidelines on the sizing and distribution of openings in buildings. The European standard EN 17037, for instance, recommends that at least 50% of occupied areas receive sufficient illuminance during half of the daylight hours of the year.
Illuminance is measured in lux (lx), an International System unit representing the amount of luminous flux incident on a surface, equivalent to one lumen per square meter. Its analysis can be performed through lux meter measurements, computer simulations, manual calculations, and qualitative assessments, considering factors such as solar orientation, window size and positioning, glass light transmittance, and impact on visual comfort. Different spaces require different lighting levels: kitchens and dining rooms demand 500 lux; bedrooms and bathrooms, 300 lux; home offices and study areas, 500 lux; while hallways and staircases need 100 lux for safe navigation.
