As-built drawings record the final constructed condition of a project. They start as a copy of the original bid set and are marked up throughout construction to capture field changes, material substitutions, and deviations from the original design. Common changes include relocated electrical outlets, modified framing due to site conditions, different HVAC layouts, and updated dimensions once the actual structure is in place.
Once the project reaches substantial completion, the contractor compiles the marked-up set into final as-built drawings, typically produced in CAD. Some lenders require as-built drawings before final disbursement, particularly on complex projects or custom builds. As-builts are also invaluable for the new homeowner and future service providers because they show where utilities run, load-bearing walls are located, and what’s actually in the walls. They’re especially important for warranty work: if a plumbing leak appears years after close-out, the as-built drawing shows where the lines run. Creating and maintaining as-builts during construction prevents disputes at the end and provides a genuine roadmap for the building’s lifetime.