Why the cleaner is the right person to notice
Cleaners walk every room of a building on a regular cycle, including the ones nobody else enters between visits. They touch surfaces, run taps, empty bins and open doors. That produces a level of contact with the fabric of a building that no periodic inspection matches. A dripping cistern, a flickering fitting or a smell in a store room will be found by the cleaner well before it is found by anyone else.
The value only materialises if there is somewhere for the observation to go. Without a route, the cleaner has three options: mention it to whoever they happen to see, write it somewhere nobody reads, or say nothing. All three produce the same outcome. Establishing the route is a small piece of work that unlocks something the building is already generating for free. The building is already producing that information; the question is only whether anyone collects it.
