As-Built Drawings and Redlines: From Field Markups to the Record Set

The field set comes back from site at the end of the job rolled in a tube that lived behind a truck seat. It has a coffee ring on E04, pencil notes from one tech, Sharpie from another, and a terminal change on the PLC rack that you know was made at startup because you were there, and that nobody wrote down. The drafter gets the tube at closeout and is asked to produce as-builts. What they produce is a guess with a title block.

As-builts are cheap when they are captured the day a change happens and expensive when they are reconstructed months later. This article covers who marks up, the conventions that keep a markup readable, how to keep the set current during the job, the difference between as-built and record drawings, and what the closeout spec usually asks for.

Who marks up

The person who made the change marks it up, the same day. On a controls job that is usually one of three people:

• The panel shop, for anything changed during fabrication or FAT: a relocated terminal block, a substituted relay, a wire renumbered to fix a duplicate.
• The field tech, for anything changed during installation and termination: a device mounted somewhere else, a spare conductor pressed into service, an I/O point moved to a different channel.
• The startup engineer, for anything changed during checkout and commissioning: rescaled analogs, swapped I/O to fix a rotation, network addresses reassigned.

Keep one master field set per job, in one place, and make it the only set anyone marks. Five partial sets on five clipboards merge into one set about as well as five spreadsheets do.

Redline conventions

A widely used convention reads red for additions, green for deletions, and blue or black for notes that explain rather than change. Many owners publish their own CAD or record drawing standard that sets colors and symbols, so check before you adopt a house rule.

Color alone is a weak convention, though. Red and green are the pair most often confused by readers with red-green color vision deficiency, and both turn the same gray on a photocopier or a cheap scan. Give every mark a second cue that does not depend on color:

• Cloud every change, so the reader finds it without hunting.
• Strike through deletions with a single line, never erase or white out. The original must stay readable.
• Write additions as new text or linework with an arrow to where they go.
• Add a delta or a note number beside the cloud, tied to a short note in the margin.
• Initial and date each change.
• Reference the source: the RFI, field change, or change order that drove it.

A markup that follows these rules still reads correctly in black and white, a year later, to someone who was not on site.

What to redline on a controls job

The approved panel drawings are the obvious target, but they are rarely the only drawings that drift. Keep an eye on:

• Wire numbers, terminal numbers, and conductor colors.
• I/O assignments: point moved to a different channel or card.
• Device locations, mounting heights, and enclosure positions.
• Conduit routing and cable runs, if routing is in your scope.
• Network topology, addresses, and switch port assignments.
• Panel layout and bill of materials substitutions approved during the job.
• The I/O list and instrument index, which must agree with the drawings at the end just as they did at submittal.

Setpoints and tuning values belong in the as-left program and the sequence of operations, not scribbled on a schematic. The drawings record how things are wired. The program records how they behave.

Keeping redlines current during the job

Redlines go stale in the gap between the field set and the office. Close the gap on a schedule:

1. Mark the field set the day of the change. Not at the end of the week.
2. Transfer weekly from the field set to a master electronic markup in the office. A phone photo of the marked sheet, sent the same day, is a reasonable bridge.
3. Tie markups to change events. Every RFI answer, field change directive, and change order that touches your work gets a redline when it is implemented. If you track those documents, you have a checklist for the redlines.
4. Review the set monthly as one line on the PM's agenda: what changed, what is marked, what is missing.

Some specs require the record set to be kept on site, available for the engineer's inspection, and a few tie progress payment to it being current. Check yours. Even where the spec is silent, a current set protects you when a dispute starts with "the drawings show something different."

As-built versus record drawings

The terms are used loosely and sometimes interchangeably, so read your spec's definitions. A common usage separates them this way. As-built drawings are the contractor's marked-up prints showing what was actually installed. Record drawings are the final set that incorporates those markups into clean drawings, prepared by the engineer, the contractor, or the owner's consultant depending on the contract, and often carrying a certification of who prepared them and from what.

For an integrator, the distinction often collapses on the drawings you authored. Your panel drawings are your shop drawings, so the record version is usually your own CAD revised to match the field and issued as a new revision marked as-built or record. On the engineer's contract drawings, you typically supply marked-up prints and the engineer or GC produces the record set. Find out which applies before closeout, because one means drafting hours in your budget and the other doesn't.

What the closeout spec asks for

Project record documents usually live in Division 01 at 01 78 39, with the technical section adding its own demands. The list commonly includes:

• Marked-up contract drawings, and revised shop drawings showing the installed condition.
• Annotated specifications noting substitutions and approved changes.
• Product data marked to show what was actually installed.
• The format: PDF, native CAD files, or both, and any layer or naming standard.
• How many copies, how they are transmitted, and when: before substantial completion, with the O&M manual, or before final payment.

Record documents are a closeout submittal, numbered and transmitted like any other, and the engineer can return them with comments. Put the review cycle on the schedule. A redline set returned for corrections the week of final payment holds up retainage just as surely as a missing warranty. Where record documents fit among the other closeout deliverables is covered in closeout checklist for a control system project.

A redline log keeps the set honest. One row per change, written when the change is made:

At closeout, every row reads incorporated, and the drawing revision proves it.

How Submittal Kit handles this

The pain is a pile of flattened, hand-marked scans where fixing one callout means redoing the sheet. In Submittal Kit a redline is a submittal type, and every mark stays editable on top of the source drawings until you build the output. Start from an issued revision, an equipment document, or an uploaded set, and drop in a hand-marked field PDF to replay its marks as editable objects. The editor has clouds, text, arrows, lines, and a company stamp with your name and the date. Build PDF bakes the marks and warns you when the output is out of date, and the set issues with a number and a permanent record. Because marks stay data, the next round starts from the last one. See redlines.

Disclosure: I build Submittal Kit. The conventions and the weekly habit matter more than the tool you mark up in.