Schedule cleaning staff during the day so that they can make use of natural lighting

Why

Lighting accounts for almost a quarter of commercial electricity use.  Turning lights off can create considerable energy savings.

How

If cleaning staff can work during daylight hours, or when other staff are in the building and lights are already on, lights can be turned off outside business hours.

If they need to clean outside of business hours, help them find a way to have as few lights as reasonable on at a time.