Humans spend almost 90% of the time indoors; that's approximately 20 hours a day in closed rooms and 9 hours a day in our own bedrooms. The architectural configurations of these spaces are not random - that is, they have been designed or thought of by someone, and are at least slightly "guided" by the conditions of their inhabitants and their surroundings. Some people inhabit spaces specially catered to their needs and tastes, while others adapt and appropriate designs made for someone else, perhaps developed decades before they were born. In either case, their quality of life may be better or worse depending on the decisions that are made.
Understanding the importance of carefully designing our interiors, particularly through the lens of access and enjoyment of natural light, was the purpose of the 8th VELUX Daylight Symposium, held on October 9 and 10 of 2019 in Paris. This year, more than 600 researchers and professionals attended and reaffirmed the importance of natural light, presenting a series of concrete tools that could help quantify and qualify light by designing its entry, management, and control with greater depth and responsibility.
Natural light nourishes physical space and impacts people's lives
Architects seem to agree: today, more than ever, it's essential that buildings and homes incorporate natural light and fresh air as a fundamental part of their environmental conditions. Whether through new designs or transformations of existing buildings, natural light – properly manipulated – can deliver much of the quality of life that the density of large cities makes increasingly difficult to achieve. Although this claim seems obvious, other issues are often prioritized, especially when resources or technical knowledge are scarce.
We humans can spend 3 weeks without food, 3 days without water, but only 3 minutes without air. And the health problems associated with an unhealthy space (poorly lit, poorly ventilated, noisy, excessively cold and/or hot) result in very high expenses for people and, on a larger scale, for governments. Thus, this issue is more complex than just 'add windows'. Its arrangement must not be random and the understanding of environmental conditions must be profound, delivering specific solutions in accordance with the architectural space and its functions.
Along these lines, Nicolas Michelin, founder of ANMA, presented a series of projects in which natural light was used in consideration of their occupants, associating it with large central meeting spaces. In the ARTEM University Campus in Nancy, France, for example, the architects designed a naturally ventilated gallery 700 meters long covered stained glass.
Here, the light is managed and screened to create a unique collective space: "The gallery is both a center of student living and a brand new public space. It is set to become a key focal point for the city, unique in its dimensions and spatial qualities," they comment in the description of the project.
A similar operation was developed by the architects of Cui Kai Studio in the design of the China Pavilion for the Beijing International Horticultural Exhibition 2019. Its large interior space is covered by a steel and photovoltaic glass structure, which absorbs energy from the sun while also collecting and storing rainwater. In this case, sunlight not only nourishes and activates the functions of the interior, but also incorporates sustainable solutions of high impact for its users and context.
Research and new technologies: design tools focused on natural light
Virtual Reality, simulators, predictive software, saliency maps, and innovative measurement systems. A series of recent advances and research have allowed us to develop new methodologies to quantify and qualify the lighting and other environmental conditions of our projects. And although each place in the world presents a particular climate, studies such as the one presented by Clotilde Pierson, Ph.D. Candidate of the University of Louvain (BE), indicate that people from different cultures do not show significant differences in their subjective perceptions of indoor natural light. Observations of human behavior, the application of appropriate measurement tools, and a hint of intuition could result in valuable contributions to the design of the buildings of the future. How will this architecture relate to natural light?
Design molded by environmental conditions
In their presentation titled 'Can natural lighting shape architecture?', Aline Branders, Sebastian Moreno-Vacca, and the architects of A2M consider the importance of designs shaped by 'flows' such as energy, humidity, and light. Their approach is to respond to these conditions with the sensitivity of passive design, using the tools and technologies available to empirically guide the process:
"New tools and software allow us to precisely acknowledge the implications of the building envelope as soon as the first sketch is created. We aim to design buildings that don’t rely on high technology and mechanical input to be comfortable but on the physical design of the volume itself. It means relying on the physical capacities of the materials (insulation, mass, shading, glass...) instead of the mechanical energy of the systems (heating, cooling, artificial, light...)."
Design focused on creating healthy spaces
It's clear: a poorly lit room is a perfect space for the incubation of microbes. According to research led by Kevin Van Den Wymelenberg, Ph.D. of the University of Oregon (USA), "Microbial communities are found in the dusty corners of buildings, on floors, walls, and in the air. Indoor dust includes particulate matter that settles from the air, impacting indoor air quality and providing the moisture and nutrients needed for microbial communities to thrive indoors."
To increase their understanding of this relationship, Van Den Wymelenberg and his team of researchers developed experimental and controlled spaces, replicating different temperature conditions, relative humidity, and daylight exposure. The results of the study, which concluded after 90 days, indicate that sunlight deactivates certain taxa in microbial communities, reducing their flowering and propagation.
Design conceived from people's needs
Glare and thermal discomfort are conditions that could affect us all. And although they can be controlled through user-managed systems, such as blinds or solar screens, there are automated and responsive systems that could be much more efficient and accurate when handling the shadow levels of interior space.
For example, the obstruction maps presented by Andy McNeil, specialist in façade behavior of Kinestral Technologies (USA), allow building technologies to check the position of the sun in real-time and thus determine the 'shadow state' of a specific window: "These maps allow the dynamic façades to admit diffused daylight when a window is in shadow for prolonged periods of time, improving daylight amenity provided to occupants." In addition, they provide a visual record of the light conditions of a building when installing the device.
For people with reduced mobility, there exist software programs that identify and score potential visual risks within a space, helping us design safer and more accessible environments in consideration of different degrees of lighting and shade. For example, at a certain time of day, the edge of a step could go unnoticed because of a low-contrast light, causing accidents. Situations such as these could be avoided by using predictive tools such as this prototype presented by Rob Shakespeare, Lighting Designer at the University of Indiana (USA) and a member of the Designing Visually Accessible Spaces (DeVAS) group.
Design based on efficiency and profitability
Vivian Loftness, a professor at Carnegie Mellon University in Pittsburgh (USA), said in her presentation that "a certain degree of quantification is essential for investors to opt for high-quality natural light solutions." The idea is to be able to demonstrate with concrete data the savings generated by the design decisions, for example, by quantifying the number of years in which the investments made will be recovered by opting for a specific solution. "We need systems that are turned off as long as possible – buildings that ‘surf” through hours, days, months and seasons," she added.
In the same way, the ability to ensure the precise amount of natural light that the different interiors of a property will receive can help increase its profitability. According to the study presented by Christoph Reinhart, head of the MIT Construction Technology program in Cambridge (USA), the value of a lease in well-lit apartments in Manhattan, New York, is on average 5% higher than in those with low natural lighting. In the study, the metric used was the spatial autonomy of daylight (Spatial Daylight Autonomy or sDA), which describes the 'percentage of habitable area' that receives enough natural light. To be considered 'well lit', space must receive at least 300 lux for at least 50% of the hours in which it is used.
The importance of darkness
The presentation by Suzanne Deoux, Doctor of Medicine and Professor at the Université d'Angers (FR), reminds us that the levels of darkness in an interior space are as important as their light levels. Natural lighting synchronizes our biological rhythms, and darkness, especially, is necessary for our bodies to secrete melatonin, a hormone that regulates the cycle of sleep and wakefulness. Light and noise pollution at night is potentially harmful to people's health, effecting the development of diseases such as breast cancer, diabetes, or obesity. Therefore, darkness must also be considered when designing with light in mind, making sure that the same openings that allow daylight to enter can supply necessary darkness, in quantity and quality, so that our internal clock works correctly.
We spend almost 90% of the time indoors, will it always remain that way?
This percentage is repeated like a mantra. Increasingly extreme climates and increasingly populated cities don't suggest a very different picture. Meanwhile, the ways in which we inhabit these compact interiors are gradually changing, driving the development of open and collective typologies such as those presented by Carla Cammilla Hjort, Co-Founder and Director of SPACE10 (DK), based on her research How will we live in the year 2030?.
A deep understanding of the interaction between buildings, sunlight, and natural environmental conditions is essential, allowing us to correctly guide increasingly prevalent trends and ensuring, at least, quality environmental conditions for the millions of people who will continue to make our architecture their home.