A scope of work states what the business will do for the price quoted.
Exclusions matter as much as inclusions
A scope listing only what is included leaves everything unmentioned open to argument, and the customer's assumption is usually the more generous one.
Stating what is not included — disposal, making good, permits, work behind or beneath the area, materials supplied by others — costs nothing and prevents the argument.
What is assumed
Most scopes rest on assumptions that are not written down: access at particular times, the condition of what is behind the wall, that power and water are available, that the site is clear.
Written as assumptions, a change in any of them is a visible reason for a change order rather than a disagreement.
Scope creep
Small additions agreed on site, each too minor to raise, accumulating into unpaid work.
It is rarely anyone acting in bad faith. It is the absence of a threshold at which something becomes a change rather than a favour, and the cost lands in job margin where it looks like a pricing failure.
Its relationship to price
A scope and a price are one document. A quote without a scope is a number attached to nothing, and it cannot be defended when the work turns out larger than the customer pictured.
For ongoing work
Recurring work needs the same treatment: what is covered by the agreement, at what frequency, and what is charged separately — see service agreements.