As-Built Drawings: The Record of What Was Actually Installed

Why it matters on a project

Every future change to the building depends on this document.

Adding a meeting room means knowing where the sprinkler main runs. Moving a desk cluster means knowing where the floor boxes are fed from. Investigating a leak means knowing which pipe is above that ceiling tile. Without a record, all of those start with opening up ceilings and floors to find out.

The cost of that, repeated over a building's life, dwarfs the cost of producing the drawings properly in the first place.

Three sets of drawings, three different things

Drawing set	Shows	Produced by
Design	What was intended	Design team
Shop / fabrication	How it will be made and installed	Contractor or specialist
As-built	What was actually installed	Contractor, at completion

They differ because construction always involves change — a clash resolved on site, a route altered around a structural member, a substituted item with different dimensions. Those changes are precisely what the as-built set exists to capture, and precisely what gets lost when it is produced from memory.

The failure mode

As-builts are meant to be maintained as work proceeds, with changes marked up when they happen.

In practice they are often assembled at the end, by marking up the design set from whatever notes survive. Changes made early in the programme, by trades who have long since left, are the ones that go unrecorded — and those tend to be the deep services changes that matter most.

The practical control is to require marked-up records at interim stages rather than only at completion, and to tie the final deliverable to a payment milestone.

What belongs in the handover pack alongside them

• Operating and maintenance manuals
• Test certificates and commissioning records
• Equipment schedules with make, model and serial numbers
• Warranties and their start dates
• Spare parts and attic stock schedule
• Training records for the client's facilities team

Documentation and record requirements sit within the administrative framework of NBC 2016, Part 2, with building services covered in NBC 2016, Part 8.

Common mistakes

• Producing them at the end from the design set. Early changes are lost.
• Accepting PDFs only. The next alteration cannot build on the record.
• Not tying them to a payment milestone. They arrive late or incomplete.
• Omitting the level of detail from the contract. "As-builts" without a defined scope gets interpreted minimally.
• Storing them where nobody can find them later. A record the facilities team cannot locate is the same as no record.

Standards referenced

Administrative provisions covering documentation and records in NBC 2016, Part 2; building services provisions in NBC 2016, Part 8. The required scope, format and detail of as-built documentation for a specific project is set by the project's contract and consultants.