Friday, September 4, 2009

The Pantheon



The Pantheon in Rome is a great theater for the display of sunlight. It depends for its illumination on a single opening, an oculus located at the center top of its dome, just where one would expect solidity. The domed rotunda is a great space and vessel for light, but daylight is not distributed as well as it might be.

The entry of sunlight is dramatic. The movement of the sun though the sky can be traced as a bright splash that moves across the interior surface of the dome; the impact of this is heightened by the otherwise relatively low light levels. It’s just not that bright inside the rotunda; inside, it feels a little like inhabiting an old sepia photograph. Top lighting can be very efficient as it is capable of distributing light equally from a central point. In this building, the surfaces of the dome redirect some light downward, but these surfaces are not, or no longer highly reflective. Clearly, the ancient marble floor is reflecting a substantial amount of light back onto the rotunda surfaces. But seeing to the walls sometimes requires additional effort, a squint, to focus on the details.

When you step into the Pantheon, you step from the real world into an ideal world, from the everyday world into an idea about the shape of the universe, from the remains of the Roman Empire into the Roman spiritual cosmos. The visual result is one of visual comfort but at seeing through a thin brown veil, or through history, to the drum’s surface of colored marble and shadowed niches, and coffered concrete.

Sunday, August 9, 2009

Notes on Complementarity 3


The Case for Non-Uniformly Lighted Spaces

There was a time when a room uniformly illuminated by electric light was seen as innovative and efficient. The opportunity to work continuously and effectively without the drawbacks of the daily and seasonal cycles of day and night, long and short days, represented the promise of increased productivity at work and even at home. Constant and uniformly distributed electric lighting overcomes the unreliability of daylight, which may leave some areas too dark and, just as easily, other areas too bright. Daylight varies from moment to moment. Direct sun can overheat a space in summer while its absence leaves us shivering in the winter. Daylight is just unreliable.

We thought, for a time, that our engineering sophistication and the availability of inexpensive electricity permitted us to overwhelm the inopportunities of the sun. Think of the gleaming insistence of a fluorescent room with its almost subconscious greenish prejudice. Rooms like this broadcast light from so many sources that strong shadows are cancelled. Without shadow, we lack clues to depth, distance, and orientation. There is evidence for a link between uniform electric lighting and worker inefficiency—exactly the opposite of what was planned. More often now, we see the presence of unvarying light, illumination of a constant intensity and color--particularly light of an un-sunlike color bias--and lacking distinct shadow, as discomfiting. Think of a room you hate: this is that room.

To take advantage of daylight, we have to design each façade of a building a little differently. Daylight from different directions has different characteristics and they correspond to different times of day and the seasons. Each orientation of a building has to perform in a different way to provide the correct measure of control over incoming light. The asymmetry of daylight can never be eliminated, but it can be exploited to enliven spaces, animate facades, and gain energy advantages. Building envelope design should be responsive to the sun and skylight and open to variation and so should interior spaces. Architecture thrives when it is responsive, when it accepts and makes sense of the qualities of daylight, including its variability.

Wednesday, August 5, 2009

Notes on Complementarity 2


The Overlapping and Simultaneous Qualities of Light

It is typical and entirely logical that multiple characteristics of light appear simultaneously. Imagine light doing only one thing at a time. We’d see light sources, but no surfaces would be brightened. Or, we’d have bright wall surfaces without a source. Light in a space might only be one color. We’d have spaces of endless shadow or in uniform dimness. These singular events sometimes happen and they can be dramatic, but it is more common that we see light performing in various ways and altogether sensible that we design spaces that invite an array of daylighted events to occur.

Dependency on one characteristic makes most spaces less useful, less interesting, visually stagnant, and even inefficient. They separate us from the changes in daylight that occur during the day. Change and variation in lighting are not necessarily distracting or confusing. They are necessary.

In most buildings and even within single spaces, we should see a carefully designed range of daylight character and quality. We should see light sources and brightened surfaces, diffused reflected light as well as specular reflections, mirror-like in their accuracy. There should be shadows, shade, dim light, sometimes punctuated with bright sources or a beam of light selecting finding a target, and so on. By these means, among others, daylight may orchestrate the organization buildings. This enables daylight and shadow to direct us, making important things visible, other places stimulating or restful, and whole buildings logical and coherent. Light is not about one characteristic or quality. It is about the ensemble of those characteristics and how they perform together.

Saturday, August 1, 2009

Notes on Complementarity 1


All light is light.

Light in the everyday world is delivered by different sources: the sun, fire, electric light fixtures, lightning, and moonlight. Light from those sources may be differentiated in the sense that each source may have more of some characteristics than others. One of those sources is intense, regular, encompassing in its influence, and a requisite for life; one flickers when domesticated, but roaring when it threatens; one is constant, quiet, and subject to fingertip control; yet another arrives in a crooked flash, a near-blinding expenditure of energy; and the last is a cyclical, soft, echo of the first. But what they have in common is equally important. At the level of particle physics, the light from all of the sources is the same thing: radiation within a thin slice of the electromagnetic spectrum. It’s all the same stuff, which means that light from one source works with another without conflict. Light from the sources can be combined and no one source cancels another. The sources and characteristics are often are combined to make rich and varied architectural environments. It also means that there is no such thing as “artificial” light. All light is light.