On recommendation from @mtnygard and others, I have acquired a copy of How Buildings Learn (Stewart Brand, 1994). Highlights so far:
Buildings are designed not to adapt, but they adapt anyway, because the usages are changing constantly. “The idea is crystalline, the fact fluid.” They’re designed not to adapt because “‘Form ever follows function’ … misled a century of architects into believing that they could really anticipate function.”
We think of buildings as static, because they change at a timescale slower than our notice. They change over generations. Humans operate at some natural timescale, and we see things slower as unchanging, and things faster as transient, insignificant. We are uncomfortable with change in stuff we think of as permanent, like buildings or culture or language. It isn’t permanent, just slower than us.
A jar of honey on its side will leak. The lid doesn’t trap the honey, just slows it down. Imperceptible movement is invisible, until the whole cupboard is sticky.
Software’s pace of change can be unnaturally fast, the opposite of buildings. That makes people uncomfortable. Updating buildings, “we deal with decisions taken long ago for remote reasons.” In software, “long ago” might be last year.
As usages change, so must our environs, in brick and in computers.
What changes faster than usages? Fashion. “Buildings are treated by fashion as big, difficult clothing, always lagging embarrassingly behind the mode of the day. This issue has nothing to do with function.” The latest hot tech may not improve on the value of your legacy software. “The meaningless change of fashion often obstructs necessary change.”