Commercial projects require as-built drawings and an engineer’s certification letter if the project required engineering plan submittal and approval by the Public Works Department. For commercial projects, the engineering plan requirement is usually triggered by the stormwater section of the standards. Section 2.3 on page 28 of the Engineering Standards provides details on the content and format of as-built drawings. A project that includes standard water and sewer services, without a hydrant, main extension, or stormwater plan, would not require engineering plans or as-built drawings. Please note that some projects may require approval from additional regulatorily authorities such as DEQ, MDT, FWP, FCD, or others.