In his new book, Building Time: Architecture, Event, and Experience (Bloomsbury, 2020), David Leatherbarrow, professor of architecture, gives a series of close readings of buildings, both contemporary and classic, to demonstrate the centrality of time in modern architecture. In this excerpt, Leatherbarrow describes how the “move-in” condition of a new structure is not permanent. “The first hour of inhabitation inaugurates a history of modifications that only ends when the building falls to ruin or is demolished,” Leatherbarrow writes.  

"Forever—is composed of Nows— 
‘Tis not a different time—"
Emily Dickinson, n. 624, c. 1860

Architecture, it is said, results from the thoughtful making of space. But time is the dimension in which buildings actually come to life: how their shadows and steel engage the days and seasons of the world, how they guide the movements of people and things, and how they project the past into the future, the once-was into the could-be. Time is not a contingent attribute of the places intended in design and realized through construction but a key dimension of their structure and significance. 

Perhaps it’s no surprise that time gets little direct attention in an art dedicated to permanence. Once they’re built, we expect rooms, houses, and offices to remain as they were, as if time hadn’t passed or didn’t matter—here they are, still ready for use, available now as before, rather like one’s body. Although much in life changes, buildings seem not to. When we stop to think about it, probably some differences between appearances then and now will be allowed, changes that result from deterioration, refinishing, alterations, and so on. These are of course changes of state, not position. Even so, when compared to the aspects of furnishings and rooms that are presently apparent, qualities that once were and will be, former and future phases hardly matter—and that’s by design. An architectural work is complete when what’s meant to remain has been realized. As months fade into years, the once-was and the now stand shoulder to shoulder, as if concurrent, no matter if the floor, walls, and roof are a little worse-for-wear, having suffered the effects of inhabitation and environmental influence. Endurance is a building’s most basic task and chief ambition. 

Uncontroversial as these truisms might seem, they are contradicted by the fact that the building’s “photo-ready” or “move-in” condition never lasts very long, hardly more than a season, certainly not through the years and decades of its use, well after the builders have left the site. The first hour of inhabitation inaugurates a history of modifications that only ends when the building falls to ruin or is demolished. Even then traces remain, and thereby supply memory with a secure foothold, not only for one’s own recollection, but more importantly for collective memory: traces of the Wall in Berlin, for example, or that same city’s Memorial Church on Kurfürstendamm. Famous examples aside, the beginnings of the end are often trivial. First come scuffs on the floor and marks on the walls, then re-painting and re-furnishing, leading to the insertion of new doors, windows, or partitions, and the still more significant subtractions and additions that will come later. Succession follows on the heels of inception; new appearances supplant old, veiling the initial conception, although their appearance rarely attracts notice. Retrospective views of resemblance do not overcome; they reaffirm these differences. My thesis is that a key task of design is making space for this kind of time, the time of continual change, without, however, disavowing the desire for permanence.

Everyone likes landscapes of newly fallen snow, before they’re spoiled when the day begins. Pristine buildings have a similar appeal, before the residents move in. When trying to describe the settings in which we actually live our lives, however, there is no good reason to privilege a work’s first over its later appearances, nor to judge any present condition as necessarily superior to those that preceded and will follow it. The tendency among professionals, professors, and critics to concentrate on the qualities of the work that display the designer’s intentions is a disciplinary prejudice that neglects the reality of a building’s post-professional life. I realize this observation runs against the grain of most building restoration campaigns, no matter whether they are undertaken by preservationists, historians, or the designers themselves. The target of their efforts is normally the work’s uninhabited condition, before its years of suffering began. 

The truth of the matter is that many buildings improve over time. Maintenance doesn’t always wind the building’s clock backwards. Improvements can result from modifications that compensate for inadequate foresight or faulty execution on the construction site. Positive changes can also result from the installation and operation of manual instruments or digital devices that improve a work’s usefulness. They alter its appearance as well. Today, buildings that incorporate some of these devices are said to be “intelligent.” A smart façade, for example, is one that incorporates instruments that moderate climate, accepting or rejecting free energy from the external environment, while reducing the amount of artificial energy required to achieve comfortable internal conditions. Materials, too, can be smart, which is to say endowed with their own manner of intelligence, more or less successfully and reliably. But design is not required for changes to occur; alterations can also result from a work’s natural tendency to settle into its location, absorbing into its physical body qualifications that can render it more congenial to ambient conditions, including light, air, and temperature together with patterns of use and, more broadly, cultural norms. Here the intelligence expressed by the work has its source in the world, not the design. Taking the long view, it would seem that buildings have no choice but to submit themselves to re-qualifications of this kind, for though they are often unforeseen they are also unavoidable. Cumulatively, they would seem to be fateful. Georg Simmel, speaking of material change in his essay on ruins, said that in every instance of building nature eventually reclaims what was taken from it. Progress toward that end takes many forms. Considering surface alterations, for example, the spectrum ranges very widely, from bleaching, absorption, saturation, and staining, to polishing and abrasion. One of the most well-known instances of abrasion—not from natural but human forces—is the dishing of stairway treads that occurs over years of use, a re-profiling to which thousands of anonymous individuals contribute unknowingly. The result is not only prominently visible, but also usefully legible, showing the path most have preferred. Another eloquent example is the festive or seasonal whitewashing of vernacular buildings.