The perceptive experience

The second part of the literature presents the perceptive human experience – a study that introduces the skylight as the aperture being investigated and then elements of our perception, linked to sky windows and views.

Skylights: visual confluence between outside and inside

This chapter gives context to two types of toplighting methods people are accustomed to experiencing the sky through and emphasizes the one that will be referred throughout the rest of the paper.

Architects’ concern with daylight has been motivated thus far by a need to manage the indoor climate, preserve comfort, and pierce the skin of the indoor area to allow light. The window has traditionally served as the principal interface and filter for daylight (Velux, 2011, p.51).

Toplighting, the broad term for getting daylight into a structure from above, was one of the earliest, and continues to be one of the most effective architectural strategies for daylighting an interior space and creating the connection with daylight. This design feature has been in use since ancient times – smoke holes on the roofs of Native American tepees and kivas allowed smoke from fires to escape and light from the sky to enter, while the Greeks and Romans refined the use of courtyards and atria in their structures to let light in from above as well (Heschong, p.136). A glazed skylight window, often known as a roof window, is used in the modern day. A roof window is best known as a view window installed at eye level in a sloped roof, whereas a skylight is installed overhead and designed to offer illumination but no look out other than that of the sky.

Roof windows have been demonstrated to offer at least twice as much light as vertical windows of the same size under identical conditions, and three times more light than dormers of the same size (Figure 6). The roof window also gives a wider range of light levels, increasing the aesthetic

attractiveness of the space. Roof windows, in addition to providing more daylight, have been demonstrated to provide higher wall luminance than dormer and facade windows, resulting in a gentler transition between the high brightness of the window pane and the surrounding wall, reducing the danger of glare (Velux, 2014, p.49).

As physical dimensions of the aperture, such as height and size, are not relevant to the scope of this study, we will further refer to the aperture as “skylight”, to emphasize its role of illuminating and providing access to the sky. Toplighting provides a variety of significant benefits as a daylighting approach, which has not been contested, but rather emphasized in a great amount of research today. For starters, it directs sunlight far into a place, where it is most beneficial. Secondly, the toplighting opening, also known as the aperture, is likely to view far more of the sky, and a brighter part of it, than a window installed on a wall. This goes to show the dual function of toplighting openings, which consequently creates a dual form of experience: that of the inside world (of the home) and the outside world (the surrounding environment and life), where the geometric shape of the window to the sky is the gateway to those experiences.

Figure 6. Comparison of daylight factor levels along the depth of a room (Source: Velux)

Changing elements of the sky

A look outside enhances the desirable experience of window views, particularly for natural, beautiful, and intriguing sights and have been discussed in the context of roof windows, like the sky and its elements. However, the mechanisms underlying the experience of skylight views are not entirely understood (Knoop, p.433). One significant contributor to how desirable these views are is how often and how quickly they change (Heschong, p.145). An amplified type of change that can is experienced through a skylight window is a result of daily weather. In a place

like Denmark, this tends to be more visually entertaining, as there is always motion on the sky. Other irregular events happening outside our dwellings, that can be observed through a roof aperture, such as street parties, parades, fireworks – give extra meaning to the skylight window view, adding both memories of the past event and anticipation of the next (ibid.). Therefore, unpredictability increases the desirability of such view.

Adaptation is the most prominent aspect of human vision that perceives change. All we perceive has a reference level, whether it is brightness, darkness or color, and we interpret it in terms of that reference level (Lam, 1986, p.13). Hence, every visual perception has some basis in old or current knowledge subjected to each individual’s experience, context and anticipation. Simultaneous contrast influences both brightness and color. Similarly, the view out a window may be several times brighter than the interior; nonetheless, this difference in brightness will only be unpleasant if the two are in strong contrast. Illuminating the wall near the window creates a transitional space, which reduces the contrast created by the aperture.

Light and color variations, as well as contrasting shadows, contribute to how we perceive daylit spaces and consequently, the surrounding environment. When sunlight and daylight combine, they produce a wide range of lighting patterns. The circumstances in which these perceptions emerge are intricately linked to 1) the sun’s location in the sky, when visible, 2) the clearness or haziness of the sky, 3) the appearance of different cloud types and 4) the properties of the natural and man-made reflecting environment (Mardaljevic, p.558).

The term skylight refers to the light reflected from the sky (Figure 7), that being the sunlight which has been scattered by particles in the atmosphere that travels each way (Heschong, p.94). Because its light is diffuse, one perceives its cast shadows as soft. For this reason, when it permeates a skylight window, it provides a general illumination that appears diffuse. The softer shadows and bluish light of daylight create a gentler ambience, especially favoring the rendition of all colors. A sensible phenomenon is sunlight scattering in the atmosphere, which occurs when sunlight is variably dispersed by random molecules. Short blue wavelengths are dispersed the most, giving the sky its blue hue, but longer-wave, yellow and red wavelengths, travel farther and are scattered less. (Heschong, p. 101). Sunlight scattering thus explains why the sky is so changeable in hue, in this sense, the color of the sky being an illusion that fluctuates significantly depending on your vantage position relative to the sun.

Sunlight refers to the light ray that travels in parallel beams directly from the sun (Heschong, p.93). Sunlight is characterized by its intense brightness, the sharp shadows it creates, and its reflection off glossy surfaces provides highlights that are nearly as bright. Because human eyes are accustomed to midday sunshine as an evolutionary reference for pure white light, sunlight

also serves as a scientific reference for a full-spectrum light source, providing the most accurate perception of all hues. Sunlight also introduces an element of radiant heat, commonly known as infrared radiation (IR), which, depending on the temperature, may be beneficial or unpleasant. We can detect extremely modest quantities of solar heat through our skin sensors. After gaining a wider understanding to discuss daylight and the color property it accompanies the sky, we now have a deeper look at daylight as a source of illumination that travels through roof windows.

Figure 7. Components of daylight (Source: Velux)

The fascinating sky view

“Look at your feet. You are standing in the sky. When we think of the sky, we tend to look up, but the sky actually begins at the earth. We walk through it, yell into it, rake leaves, wash the dog, and drive cars in it. We breathe it deep within us. With every breath, we inhale millions of molecules of sky, heat them briefly, and then exhale them back into the world.” (Diane Ackerman)

According to Heschong, the positioning of a window, or more broadly, an aperture, impacts not just the flow of light into a structure, but also the view out of a building (p.151). Few other architectural features serve such clearly dualistic, and sometimes contradictory, functions. Where we want the maximum daylight illumination in a space may not be the same as where we want to gaze out.

Ultimately, creating a symphony of daylight illumination within a building may conflict with the perspective we want of the world outside (ibid.). One of the difficulties of effective daylighting design is resolving this disparity. We discussed the relative brightness of a view earlier, whether it is sunlight or in shadow based on direction and time of day. Later, we discussed how to balance

the brightness patterns inside a space by bringing in daylight from numerous directions and diffusing direct sunlight as it comes in.

If previously we looked at how the path of the sun through the sky is entirely understood and predictable, here we can mention that the sky itself, has many elements in relation to the perceptive experience, that are impossible to reproduce. Many of these items of the sky move in an unorganized way and cannot replicate their reality by any simulation tool. Views provided by the roof window give information on diurnal and seasonal changes, as one is aware of, as well as the extra visual interest of the moving clouds, birds, floating particles, pollen clouds and other transient activities, all of which provides cognitive stimulation and respite from the more regulated inside environment. They therefore offer a unique experience to the viewer at any moment in time.

But what generally constitutes the benefits of a view to the sky is, in some respects, a fairly difficult wondering, due to the intricacy. There have been a few studies that have attempted to identify various perspectives, but most would agree that thorough study on sky views is still in its infancy (Heschong, p.155). We will begin by exploring the more tangible aspects of views top lighting that people experience, such as the sky and its ephemeral elements then advance to more abstract features, such as complexity, ambiguity, and change (FIgure 8). This chapter then concentrates on perceptual characteristics, whereas subsequent chapters will look at the deeper emotional, social, and cultural relationships we create with views.

The sky is usually described as an important aspect of any view. When they can see the sky, people frequently express simple appreciation for this experience. But what is it about the sky that makes it so special? When Lisa Heschong asked respondents why they appreciate their office window view, the most common response was “I want to know what the weather is doing.” (p.157). This makes a lot of sense in areas where the weather is very variable and unpredictable, similar to Denmark, where rain and clouds come and go swiftly throughout the day. This leads to the possibility that knowing the weather is a code for some other need or desire.

Figure 8. Renderings of the sky during the day, with its fascinating variations (self-produced)

Temporal orientation is a strong candidate, according to Heschong (ibid.). A view of the sky is likely to contain the chance to see a ray of sunshine entering the room, creating a dramatic time marker for the day, as well as the chance to see the changing hues of dawn or dusk. As previously noted, atmospheric dynamics offer a temporal foundation for the day: humans intuitively evaluate the time of day based on the hue and brightness of the sky.

But the sky with all its glory, is not just something to gaze at. In her meditative book “A Natural History of the Senses”, Diane Ackerman defines the sky as the lively environment we live inside, the medium of our existence: “Take a look at your feet. You’re up in the clouds. We tend to glance up when we think of the sky, although the sky truly begins at the earth”. She goes on to describe the complexities of the living around us: “Without thinking, we commonly talk of an empty sky” – however, the sky is never empty, and it is never the same. People have to be reminded that there is so much more to be experienced, that moves beyond the roof window to the sky. “The air is always vibrant and aglow, full of vital gases, staggering spores, dust, viruses, fungi, and animals, all stirred by a skirling and relentless wind. (…) Beginning at the earth and stretching up in all directions, the sky is the thick witching realm in which we live.” (Ackerman, p.236).

Perceived restorative quality of the sky

“What is most human is not rationalism but the uncontrolled and incontrollable continuous surge of creative radical imagination in and through the flux of representation, affects and desires.” (Cornelius Castoriadis)

According to Marianne Krogh in her book Connectedness: An Incomplete Encyclopedia of the Anthropocene, “we look at nature as something that is detached from ourselves”. It is true that in recent history, we have lost sight of the close, basic link that exists between us and environment. Yet, physiological effects of light are one piece of evidence for the inevitable connection that we have to nature and our surroundings still (Ravn, Mach, Hansen, Triantafyllidis, p.1). The more we learn about light’s impacts, the more we realize that the dynamic changes that natural phenomena provides have a relationship not just to our sense of our interior environment, but also to our intrinsic reality, biological clock and wellbeing, as seen thus far.

The distinctive status of skylight windows is connected to the fact that views out the window capture one’s attention, according to the previous chapter’s premises. These distracting attention pulls, in turn, result in brief interludes that can give a break from the present activities,

resulting in a micro-restorative experience. Based on prior research, it is plausible to believe that the restorative properties of such brief pauses to the sky are dependent not only on the availability of the view but also on its content (Tennessen, Cimprich, 1995). Because each viewing opportunity may be brief, the restorative benefits of window views are most likely the result of repeated opportunities.

A study on the nature of the view from home gives substantial support for the assumption that having natural components in the view from the window helps occupants’ sense of wellbeing significantly, according to Rachel Kaplan (p.507). Views of constructed features, on the other hand, influenced satisfaction but not wellbeing. Extended restorative experiences may be few and few between for many people, as viewing out a window is more frequently lasting only for a brief moment at a time, but micro-restorative experiences, on the other hand, may be significantly more accessible.

Studies show that the health focus appears to have established daylight as a research field for the natural sciences, as well as for architects and engineers, which transforms daylight into a phenomenon devoid of sociality (Hauge, p.3). Since daylight and skylight experienced from a skylight window are interconnected, we draw from these studies to investigate how people experience the phenomenon of looking at the sly next. Therefore, a qualitative study of the elements of the skylight window (dynamic patterns, light, sky) and their relation to one another will follow. With this study being conducted in residential homes, the aim will be to encourage an intentional connection to nature and to one’s wellbeing. Lastly this will be assessed in terms of restorative qualities.

However, we must acknowledge that this study cannot be left to architects, but rather to the residential occupants, who are responsible to creating generational knowledge and conduct qualitative, rather than laboratory research. This research study embraces daylight for its strength, energy and good environmental consequences, which will be given a residential application in chapter 3, later on.

As human civilization has progressed from independently dispersed structures to today’s congested megacities, the struggle and demand for daylight has grown increasingly competitive. This tendency was projected to gain traction as 70 percent of the world’s population was to be living in urban areas by 2020. As Velux writes, we have become constant ‘cave’ dwellers, more disconnected from the ‘naturalness’ of daylight, its sequencing, rhythm, and rituals and enduring a loss in health and mental advantages (Velux, 2011, p.44).

As human civilization has progressed from independently dispersed structures to today’s

congested megacities, the struggle and demand for daylight has grown increasingly competitive. This tendency was projected to gain traction as 70 percent of the world’s population was to be living in urban areas by 2020. As Velux writes, we have become constant ‘cave’ dwellers, more disconnected from the ‘naturalness’ of daylight, its sequencing, rhythm, and rituals and enduring a loss in health and mental advantages (Velux, 2011, p.44).

More reflections on the literature

The paper has so far addressed the physiological mechanisms of human circadian and cognitive systems in relation to the sky, later on exploring the visual and sensory experience related to skylights and views to the sky. These overall defined the experience of looking out through a roof window as an intrinsically desirable act. It demonstrated that the sky visually exists as a result of our predictable and perceptive grasp of natural phenomena of daylight and skylight. Therefore, the first problem statement has been answered. In order to add to the knowledge summarized above, as well as to continue to peel of the layers of the problem statement, we will further look at what meaning is attached to the phenomenon of looking at the sky through skylight windows.

Visual perception linked to skylight window views was accepted as an ongoing process of predictions and anticipation and we are now making grounds for an unfolding of a phenomenological approach, where it is expected that the sky view boosts perceptions of restorative qualities through mind wandering.