A business could ask about surfaces, accessible areas and periods when the premises are free. An assessment visit would define tasks and frequency. Tracking would distinguish recurring visits from occasional work. A change in how the premises are used would trigger a scope review before the regular calendar or expected tasks are altered.
An illustrative example to adapt to your business. It does not represent a completed project in this municipality.
Can a price per square foot be advertised?
It can provide a reference when conditions are explained. Frequency, surfaces and tasks still need verification before a price can be confirmed for the customer’s particular premises.
How should an exceptional request be handled?
Add it as a separate task requiring approval. Customers can then see its cost and scheduling effect without having the recurring service silently changed by an additional request.