What is an as built drawing?

As Built drawings document the completion of works and are an essential part of the contractor’s hand over manuals. As the need for documentation throughout the construction process increases so does the need for as built drawings and other drawings.

As Built drawings can also be called As Installed drawings, As Constructed drawings and As Executed drawings.

An As Built drawing documents the changes that have been made throughout the job and the changes that have been made since the last revision of drawings.

For example, in electrical drawings the design phase for a construction project the electrical circuits are named P1, P2 etc. (for power) and L1, L2 etc. (for lighting). On the as built drawings these circuit tags are changed to show the distribution board number and circuit breaker number that the lights (or power etc) are connected to.

For example: DB1 CB37

Another good example is that data outlets are numbered to the client’s requirements.

Sydney University uses a unique numbering system for the data network which shows the room that the cable is fed from, including rack number and port number of the patch panel. Then the room number that the outlet is located in and the number of the outlet in the room.

A typical data outlet tag in Sydney University looks like this. 524.

These can be quite challenging to add to an as built.

There are several stages that drawings take through a project, here’s a few examples.

A project will start with several stages of design drawings however the first set that a contractor will usual see for the For Tender drawings which are used for quoting.

Once the builder has been awarded the contract they take the role of Prime Contractor and pick electrical, mechanical, hydraulic, fire and security contractors to complete the project.

The next set of drawings are the For-Construction drawings where most the design changes have been made and these drawings allowing the contractor to start work.

The next set of trade drawings that aren’t normally required are Shop Drawings, these are required when a builder wants to see any potential changes the contractor can see before work starts.

Then we come to the Revision changes (usually shown as R1, R2 etc.) which document any changes the client has requested or any issues that have been resolved during the construction phase.

The next step towards As Built or As Constructed drawings is the most neglected, the contractor’s mark ups.

Pens, pencil, highlighters, chewing gums, blood, a bit of electrical tape and Bob’s your Uncle. A true mark up is not complete unless it’s been kicked around the work van for a few weeks, and has a generous splash of coffee and smudge of meat pie with sauce.


The last and probably most important stage is the As Built, As Executed, As Installed or As Constructed drawings, these critters help the contractor get paid!!

The As Built drawings are included in the hand over manual which also covers the products used during the jobs, their specification sheet and maintenance details.

As Built drawings can take anything from 5 minutes to hundreds of hours depending on the size of the project.

As the need for more details are required many Australian projects are now being completed using Revit models. Revit allows the engineers, contractors and clients to view every facet on the job in 3D. With addition of programs like Navisworks clash detections allows any potential issues to be resolved before construction begins.

If you need any help with As Built drawings or any other revisions, please feel free to contact us at Drawable on (02) 9519 0000.


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