There is no universal schedule
A quiet professional office with ten employees has different needs from a call center that runs two shifts. Start with daily headcount, visitor traffic, food areas, restroom use and floor type. These details are more useful than square footage alone.
Common service patterns
Small low-traffic offices may do well with one to three visits each week. Busy offices often need weekday cleaning, especially for restrooms, kitchens, trash and entrances. Periodic work such as carpet extraction, floor refinishing and high dusting should have its own calendar.
Watch the pressure points
Full trash cans, restroom complaints, dusty edges, fingerprints at entrances and food buildup are signs that frequency or task time is too low. Before adding a full service day, ask whether targeted attention to the busiest areas would solve the issue.
Review after the first month
Treat the starting schedule as a working plan. Review it after 30 days and again when occupancy or seasons change. A good cleaning company should be willing to adjust frequency based on what the building actually needs.
