How Buildings Learn: What Happens After They're Built

by Stewart Brand

The sequence of effects of deterioration on ordinary buildings has never been formally studied—a curious lapse, considering the massive capital loss involved—but some rules of thumb have emerged. Due to deterioration and obsolescence, a building’s capital value (and the rent it can charge) about halves by twenty years after construction. Most buildings you can expect to require complete refurbishing from eleven to twenty-five years after construction.2 The rule of thumb about abandonment is simple: if repairs will cost half of the value of the building, don’t bother. This is the point at which owners either demolish the place (often leaving a vacant lot, which is considered to be more salable than a shabby building, to the despair of city planners and preservationists), or they burn it for insurance, or they let it stand empty.