Ask the proposal to distinguish retained sections, alterations, new components and repairs. Include any new entrances and the practical maintenance access needed around the added building. If construction must finish before part of the installation can be assessed, have the remaining step clearly identified rather than assuming it is included in an earlier visit.
Obtain applicable owner or shared-property approval before altering the boundary. Keep the final work description and relevant inspection documents together. Normal operating information should reflect the completed arrangement, so future users do not rely on instructions or drawings from before the perimeter was enlarged.