The necessity of adjustments: The alley opening

The patterns of alley geometry and alley-associated buildings, where they meet the block faces and surrounding streets, may be usefully adjusted in a variety of ways. It is necessary to understand standard configurations, but also how they may be tuned to local situations.
Adjustments begin with some study of the alley’s contribution to the character of the block as a whole. While there is no predestination, different alley configurations will tend to balance the utilitarian aspects of the block interior with its social and psychological uses. Some configurations, too, are more easily adaptable over time and changing circumstances. It is wise to make a habit of consciously calibrating alley intentions, even though no certain match of form and fate is possible in any urban element.
The most rudimentary alley is the center-block “I” pattern, running equidistantly from the longer block faces down the axis of the block, and debouching without modification into the streets at the shorter faces. This is the alley at its most utilitarian, minimally masking the activities it encloses. It offers the easiest possible access for utilities and services and the most open invitation to traversal by anyone — resident, legitimate user, or not — passing on foot or by vehicle.

tactics to adjust privacy
Several tactics can adjust an alley’s visual privacy, the sense of it being semi-private rather than wholly public, and hobble the ease of movement through it. Toward such ends, both the alley travel surface and the buildings flanking it may be modified.
Necking down the alley width at the mouth to a minimal single travel lane contributes in such ways; so does pushing closer the alley-fronting building components of the two end lots. The two garages — such buildings usually are garages — then begin to behave like gatehouses for the entire block. (This has the side benefit of freeing space for the main buildings on these lots, which are usually corner lots appropriate for more intense use.) Thinking of these service buildings as gatehouses opens them to architectural treatment, including arching over the alley between them, even gating it, strongly increasing the sense of trespass. If the end lots are fifty feet or more in width, the pushed-in garage pair may use the alley for access — as there is enough backing-out space in this width — if less, they must have their aprons facing the street, and require their own curb cuts, a definite drawback.
Another possibility includes a dogleg at the alley entry, fully closing visual access to the alley interior. When the alley entry is blocked in this fashion there must be a widened area immediately behind to make the transition to the center-block main alley section. The jog must not be so drastic as to render service truck access impossible or cripple utility layouts. Providing second-floor apartments above the pairs of axially located garages (one watching the alley’s entry, the other looking up its length) adds very effective surveillance to the block.
The building that accomplishes the blocking may be like others on the alley, but it is also possible that it assumes a different status because of the different relationships inherent in its location. For example, early in the twentieth century this was often where communal garages, shared by those few households on a block owning motor vehicles, were placed. In the early twenty-first century, with the advent of the ideas of car-sharing and dispersed car rentals in more urban situations, such a use may be appropriate to revive. Similarly, it is a logical location for shared work or meeting places.
The alley entrance is one of many common, unassuming components of urbanism which, when consciously designed and adjusted, refine the experience of urban living. This is not to fetishize the quotidian; it is to acknowledge that good urbanism is not mere mechanical assembly of prefabricated elements, but a craft.

Copyright © 2006 Andres Duany, Michael Morrissey, and Patrick Pinnell. Libraries, universities, institutions, and businesses may not circulate, hire, print, use as a teaching aid, or reproduce this article and/or images without the prior written permission of the authors.��