Write down what happens now before changing anything
The first document is descriptive, not aspirational. Walk each area and note what is visibly maintained, what is clearly not, and what nobody has looked at in a while. Ask whoever manages the premises which days the cleaner attends and roughly how long they stay. If the current cleaner is willing to talk through their round, that conversation is worth an hour, because much of the arrangement exists only in their working habits.
Resist the temptation to redesign the service at this stage. An informal arrangement that has survived several years usually contains sensible local adaptations, such as skipping a storeroom that is never used or attending late on the day the bins go out. Capturing those decisions preserves them. Once they are on paper you can decide deliberately which to keep, rather than losing them by accident when the arrangement changes hands.
