It’s a tribute to the framer of this dictum that modern city planners still fervently adhere to it. The trouble is, it was made by William Penn, the founder of Pennsylvania, around the time he laid out Philadelphia in 1682. A lot has changed since then, but you wouldn’t know it by looking at our planning codes.
Even though residential building lots have shrunken from acres in Penn’s time to a few thousand square feet in our own, most suburban planning codes hardly acknowledge the difference. They still doggedly insist on strips of setback land surrounding houses, no matter how narrow or useless.
Essentially, setbacks are reserved areas on each edge of your property, like margins on a page, that you’re not allowed to build upon. The idea is to help ensure William Penn’s ideal of houses spaced well apart, with usable land on all sides. Given the long historic trend toward higher land prices, smaller lots, and bulkier houses, however, many suburban setback requirements no longer make sense.
Today’s typical five-foot side yard setbacks, for example, serve mainly to mandate sunless, useless slivers of land between houses. Yet rather than doing away with these vestigial separations altogether, moribund planning codes stubbornly cling to them, stymieing the growth of more intelligent arrangements.
Among these alternatives is zero lot-line development, a way of laying out houses so that one long side--ideally the north side--lies directly on the property line. The strip of setback land normally required on that side can then be compounded with the setback on the opposite side of the house, yielding one larger and more useful outdoor court, while leaving the actual distance between houses unchanged.
Typically, to comply with fire codes, houses in zero lot-line arrangements have a solid, windowless wall on the north. While this feature draws moans of horror from design-review zombies who demand lots of happy-happy windows, it actually enhances both privacy and energy efficiency. What’s more, it allows proportionately more glass to open onto the south-facing outdoor space.
Another land-friendly alternative is the courtyard house, which takes the zero lot-line format and bends it into a U-shape or a rectangle. In this case, all of the outside walls lie on the property line, much like an urban commercial building. Completely enclosing the court in this way gives additional space and privacy without squandering a single square inch to unusable setback land.
If these sound like radical new ideas, they’re not. Cities in Asia and the Middle East have benefitted from such arrangements for thousands of years. Nevertheless, Americans who’d like to develop their own land more intelligently still face an almost insurmountable setback battle in most planning jurisdictions. After three hundred-some-odd years, even William Penn might find that pretty silly.