As-Built Drawings and Project Handover

The effects above come from an as-built drawings overview and a CROSS safety report on as-constructed drawings.

What are as-built drawings? They are the final set of plans showing exactly how a building was built, including changes made on site. Their value depends on changes being captured during construction, not guessed at afterwards.

Handover is the closing stage of the architecture and building project phases. It is the point where drawings, manuals and warranty paperwork pass from the builder to the people who will run the building.

What goes wrong without accurate records

An owner who receives only the original design drawings is working from a document that describes the intention, not the result. Walls, ducts and pipes often move during construction because of site conditions, design changes and on-the-spot decisions, and as-built drawings are meant to capture all of those modifications. When they are missing, the gap shows up later and costs money. Design changes of any origin, including those arising from a review such as what is value engineering in construction, need to reach the final record set.

• Rework on later projects. Undocumented changes can lead to significant rework when a designer or contractor relies on the original drawings and a relocated wall or duct is somewhere else.
• Surveying before any alteration. Without reliable drawings, renovation or maintenance work needs extensive surveying and analysis. An owner planning alterations should treat this as a cost that accurate records would have reduced.
• Structural assessment. The CROSS report notes that in New Zealand the lack of accurate as-builts hinders the seismic assessment of existing structures. Owners of older buildings may meet this problem when an engineer asks for the original construction details.
• Liability. Accurate as-built records provide protection if lawsuits or liability claims related to defects arise. That is a practical reason to treat the drawings as a legal record as well as a technical one.

The usual root cause is simple. If changes are not thoroughly documented and marked on plans during construction, no later effort fully recovers them, which is why the next sections deal with who prepares the records and when.

Using the drawings to operate the building

After handover the main user of the drawing set is rarely the designer. It is the owner’s facility manager or maintenance team, who need to know what is behind a ceiling or inside a riser without opening it.

Facility managers and hidden services

As-built drawings let facility managers and maintenance teams quickly locate pipes, wires and ducts. Sets are usually divided by discipline, so the mechanical, electrical and plumbing (MEP) drawings, which show the final installation of those systems, are the sheets a maintenance team will open most often. A facility manager taking over a building should check that these sheets are present before accepting handover, because a missing discipline is much harder to replace once the contractor has left site.

Keeping the set after handover

Building owners and managers should ensure that as-constructed drawings are retained for future purposes. Retention is not automatic. The CROSS report warns that drawings are more likely to be misplaced when assets are transferred or staff change, and that the full set of final documents is not usually collated and passed on to the owner or a later purchaser.

In practice, that argues for a single named custodian, a clear storage location and an index of what was received. The index matters because a later buyer or manager can only look for what they know exists.

As-built drawings versus record drawings

The two terms are often used loosely, but they describe documents with different authors and different levels of review. Record drawings are the architect-approved versions of as-built drawings, derived from the as-built information and approved by the design professional.

• Who prepares them. Contractors usually create and update as-built drawings. Design professionals, typically architects, prepare record drawings. In the field, the as-built drawing is made by the contractor or the drafter responsible on site, and it is approved by the contractor, construction management and planning consultant, according to a Indonesian-based survey firm’s explainer.
• Level of review. The term “as-built” can carry risk because those drawings may not meet building codes, whereas record drawings receive professional review.
• What they are for. Record drawings are needed to obtain occupancy permits and for any future renovations or changes.

For an owner, the practical choice is to ask for the contractor’s as-built information and for the architect’s record drawings, not to treat them as alternatives. The first is the raw field record. The second is the version a building department or a later designer can rely on. How the design professional’s role fits into earlier stages is covered in architectural design phases.

How field changes become a drawing set

The mechanism is straightforward. Changes are usually marked in red ink on the construction drawings as work proceeds, giving a red-lined set that the contractor or field drafter later turns into clean drawings.

What the set should record

A well-prepared set shows actual dimensions, the exact locations of structure and utilities, design changes, the materials used, and revision records with dates and reasons for the changes. The revision record is the part owners tend to overlook. It explains why something differs from the design, which matters when someone later questions a deviation.

Why timing decides accuracy

The weak point is timing. As-constructed drawings are typically produced after practical completion, when many of the people with first-hand knowledge of the work have left, according to the CROSS report. A separate industry overview makes the same point about staff: drawings are often left incomplete when staff turn over.

An owner’s representative should therefore expect marked-up drawings to be maintained during construction. A set assembled from memory after the general contractor’s site team has dispersed is the one most likely to contain errors.

O&M manuals and warranties

O&M manuals are the operating companion to the drawings. The drawings show where systems are, and the manual is where an owner should expect guidance on running and maintaining them. The CROSS report goes as far as recommending that each jurisdiction require a comprehensive building manual for commercial buildings, lodged with owners, which signals how often this material fails to reach the people who need it.

The exact contents of a manual depend on the project specification, so an owner should ask for the required contents list before construction ends and check delivered manuals against it. Matching the manual to the MEP drawings is a useful test, because every system shown on those sheets should have operating and maintenance information somewhere in the package.

Warranty paperwork belongs in the same handover package. The CROSS report recommends that submission of as-constructed drawings be a contractual obligation with the responsible parties defined. Owners can apply the same logic to manuals and warranty documents, naming each item in the contract so that nobody has to assume it will be delivered.

Certificate of occupancy and handover timing

Record drawings are among the documents needed to obtain occupancy permits, so the drawing workflow affects the occupancy date. Because record drawings derive from the contractor’s as-built information and are approved by the design professional, the architect’s review needs time in the programme. Waiting until the building is finished to start that review is a common reason for delay.

The specific steps for a certificate of occupancy are set by the local building department. The most useful early step is to ask it which drawings and documents it requires, and whether it accepts as-built or record drawings. Certifiers are advised to withhold certificates until satisfactory drawings arrive, and the CROSS report notes that pressure to issue them earlier is common, so owners should not count on flexibility.

Frequently asked questions