As-built drawings are the final set of drawings produced at the completion of a construction project. They include all the changes that have been made to the original construction drawings, including notes, modifications, and any other information that the builder decides should be included. While the original drawings are typically produced using computer-aided design (CAD) software, the as-built drawings usually contain handwritten notes, sketches, and changes.
To understand how as-built drawings are created, it is helpful to understand the process of developing construction drawings. The owner or developer of a project will hire an architect or engineer to design the proposed building. These design professionals will use the owner's ideas and requirements to create construction drawings for the project. Once the owner has approved these plans, they are submitted to the local permitting agency to obtain building permits. This final set of plans is often known as the "permit set" or "100 percent construction drawings."
As the builder begins work on the project, he will use the construction drawings to lay out walls, install ductwork, run electrical wiring, and construct the remainder of the building. During this process he may run across unforeseen conditions that require items to be installed differently than they are shown on the plans. For simple changes, he will often simply work the problem out himself and note the changes on his set of building plans. With more significant problems, however, the builder must contact the architect or owner for direction.
The builder will typically send an explanation of the issue in the form of a Request for Information (RFI). When the architect or owner responds, he or she may send a sketch, a full drawing, or simply a written directive. The builder will make use this response to address the problem, and will also include the changes on his as-built drawings. Throughout the project, the owner may also issue other formal change requests to the construction documents. The builder will also include these changes on the as-built drawings as a record of the owner's requests.
On larger projects, all major contractors and subcontractors may maintain their own set of as-built drawings. This allows the electrician, plumber, drywall contractor, and other professionals to make changes without holding up the job to track down a single set of plans. At the end of the project, all sets of as-builts are combined into a single comprehensive set for delivery to the project owner. Most construction contracts include a requirement for as-built drawings, but it is good practice to provide these plans even when they are not required.
As-built drawings serve several important functions. They can inform the owner of locations for wiring, plumbing, and other hidden components to make repairs and maintenance easier. They are also helpful for future renovations, and can be used as a base when creating remodeling plans at a later date. The local government or permitting agency may also require a copy of the as-builts to show locations of sprinkler pipes, fire alarms, and other safety devices.