Benchmarks
Everyone assumes an older building costs more to service. We measured it and the assumption is half wrong: routine service does not move at all with age, while replacement work roughly doubles. Testing total revenue hides both.
Building Age Doubles Replacement Work and Does Nothing to Service Revenue
Older buildings do not spend more on mechanical service. They spend more on replacement. Split the revenue and a 1.85x effect appears where total revenue shows nothing, measured across 25,912 buildings.