As-built drawing | Chalkline

An as-built drawing is the revised version of the construction drawings that records what was actually built, including any variations from the original design drawings. As-builts are produced at or near practical completion and form part of the handover pack delivered to the client. They are the authoritative record for the building going forward.

Why as-builts matter:

Future renovation reference: an architect or builder planning future work on the building uses the as-builts to understand what’s actually there.
Defect investigation: when a fault appears years later (slab crack, services leak, wall sag), the as-builts tell the assessing engineer what was built.
Services modification: electricians, plumbers, HVAC contractors working on the building later rely on as-builts for cable, pipe, and duct runs.
Resale and finance: a complete as-built set adds to the property’s documentation, valued in resale and bank-finance contexts.
Insurance claims: insurers may require as-builts to assess damage.

What gets recorded on as-builts:

Variations from design: where construction differed from the contract drawings. The architect, structural engineer, or builder marks the variation on the relevant drawing.
Service routes: actual cable, pipe, duct, and conduit runs as installed (often different from design).
Hidden elements: service penetrations through slabs, sleeves, hold-down bolts, embedded items.
Dimensions: measured and confirmed dimensions at completion.
Levels: floor levels, ridge heights, etc. as measured.
Connection details: actual connection types for structural elements where field decisions affected the design.
Material substitutions: where alternative materials were approved during construction.

Who produces the as-builts:

Architect: typically prepares architectural as-builts based on the design set plus on-site annotations.
Structural engineer: prepares structural as-builts where structural changes occurred.
Services consultants (electrical, hydraulic, HVAC): each produces their own as-built set.
Surveyor: prepares the as-constructed survey for site-related elements (boundaries, levels, easements).
Builder: typically responsible for coordinating the as-built process and handing the consolidated set to the client.

When as-builts are required:

Mandatory: government and commercial projects, public infrastructure, multi-residential developments.
Contractually expected: most residential contracts include “as-builts at handover” as part of the deliverables, though enforcement varies.
Practically essential: complex builds where the design and construction diverged significantly.

Common builder issues:

Variations not documented during construction: the builder must remember at handover what was changed and when. Better practice: maintain a running variation register and annotate the drawings as variations are approved.
Trade as-builts not collected: each services trade has their own as-built; the builder must collect them. Discovering at handover that the sparky never produced as-builts triggers a delay.
Survey not commissioned: if an as-constructed survey was required for the OC, it must be done before completion. Often forgotten.
Client receives no as-built set: client may be entitled to ask for them post-handover; the builder is still on the hook.

Format:

PDF preferred for client handover (one consolidated file or a folder per trade).
DWG / Revit native files for builders who own the design IP and may revise later.
Plot to A3 or A1 as appropriate; standard architectural sheets are A1.

For builders:

Maintain a variation register from day one. Every change should land on the drawing or the register at the time it happens.
Brief every services trade at engagement that they’re expected to produce as-builts at completion. Include it in the contract scope.
Hand over a consolidated as-built set at PCI; don’t leave items outstanding.

Also known as: as-built, as-constructed drawing, record drawing.

Category: Compliance / handover / documentation.

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