What Are As-Built Drawings and Who Prepares Them?

As-built drawings are the contract drawings marked up to show what was actually installed: every relocated pipe, rerouted conduit, changed dimension, substituted product, and field change that differs from the design. They are usually prepared by the contractors who did the work. Each subcontractor marks up its own scope during construction, and the general contractor maintains the master set, reviews it, and turns it over to the owner at closeout. The owner then relies on those drawings for years to maintain, renovate, and troubleshoot the building.

As-builts are a contractual deliverable on most commercial projects. The requirement is usually written into the Division 01 closeout sections of the specifications (often a section titled Project Record Documents, 01 78 39 in CSI MasterFormat), which spells out what must be recorded, how often the set is reviewed, and what format the owner receives.

This guide explains how as-builts differ from record drawings and shop drawings, who is responsible for what, what each trade should record, how to keep them current during construction, and how to hand them over.

As-Built Drawings vs. Record Drawings vs. Shop Drawings

These terms are often used loosely, and your contract is what actually defines what you owe. In general:

As-built drawings are the marked-up drawings (often called redlines) that the contractor and subs maintain during construction to show deviations from the design. They are field documents first.

Record drawings are typically a clean set prepared from the contractor's as-built markups, often by the architect or engineer, that incorporates the changes into the drawing files. Some contracts ask the contractor to produce this final set; others assign it to the design team.

Shop drawings are drawings prepared by a subcontractor or fabricator showing how a specific item will be fabricated and installed (steel connections, duct layouts, sprinkler layouts, millwork). They are submitted for review before the work is built. Approved shop drawings often feed into as-builts, but they are not a substitute for them.

Redlines are simply the markups themselves, named for the red pen traditionally used.

Who Is Responsible for As-Built Drawings?

Subcontractors record changes to their own scope as the work is installed. The electrician records conduit and circuit changes, the plumber records valve and cleanout locations, and so on. The subcontract should flow down the as-built requirement from the prime contract.

The general contractor maintains the master as-built set on site, collects markups from each trade, reviews them for completeness and legibility, and records GC-performed and architectural changes. The GC also makes sure RFI answers, change orders, and design bulletins are reflected.

The architect or engineer reviews the as-built set when the contract requires it, and may produce the final record drawings from it. Some contracts have the architect check the as-built set as a condition of approving monthly pay applications.

The owner receives the final set, often along with O&M manuals and warranties, and keeps it for facility management.

What to Record on As-Builts: A Checklist by Trade

The general rule: record anything that differs from the drawings, anything concealed that someone will need to find later, and the location of anything that needs maintenance access. Dimension concealed work from permanent, findable references (grid lines, finished walls, building corners), not from temporary objects.

General and architectural

Wall, door, and window relocations or size changes
Changes to ceiling heights and floor elevations
Concealed blocking and backing locations
Access panel locations
Product substitutions and where they were used

Structural

Footing and foundation changes, including changes in bearing elevation
Embed and anchor bolt locations that changed
Added or modified framing, openings, and reinforcement

Site, civil, and underground utilities

Horizontal location and depth of every underground line, dimensioned from permanent features
Inverts, cleanouts, valves, and fittings
Abandoned or capped lines found during excavation
Utility crossings and conflicts that were resolved in the field

Plumbing

Shutoff valve, cleanout, and trap primer locations
Changes to pipe routing, especially in walls, slabs, and underground
Water heater, backflow, and equipment locations

Mechanical and HVAC

Duct routing changes and equipment relocations
Fire and smoke damper locations with access door locations
Equipment tags matching the equipment schedule
Valve and balancing damper locations

Electrical

Conduit routing concealed in slabs, walls, and underground, with depth for underground runs
Panel schedule changes, including circuit numbers that were reassigned
Junction and pull box locations above ceilings or in walls
Device relocations and added devices
Home run changes and feeder routing
Grounding and bonding locations
Low-voltage, fire alarm, and security device locations if in scope

Fire protection

Head, branch line, and main relocations
Riser, control valve, and test connection locations
Reference to any revised hydraulic calculations

For every trade, write the source of each change on the markup ("per RFI-023" or "per CO-007"). That reference is what lets the owner, architect, or a future contractor understand why the building differs from the design.

How to Keep As-Builts Current During Construction

As-builts done at the end of the job are reconstructed from memory. As-builts done during the job are accurate. A few habits make the difference.

Designate one master set. One set on site (paper or digital) is the official as-built set. Trades mark up that set, or submit their markups to the GC on a schedule for transfer to it.

Mark up before cover-up. Record concealed work before walls are closed, slabs are poured, ceilings go in, or trenches are backfilled. Tie as-built checks to the same moments as cover inspections.

Take location photos. Photograph concealed work before it is covered, with a reference point (a grid line tag, a tape measure against a finished surface) visible in the frame. Photos back up dimensions when questions come up later.

Use a consistent markup convention. A common convention is red for added or changed work, green for deleted work, and another color for notes, but check whether your specs define one. Whatever you use, use it consistently.

Mark the current revision. When a sheet is reissued, carry existing markups forward to the new revision. Markups on a superseded sheet can point to geometry that no longer exists.

Review monthly. The GC should check the as-built set for each trade on a regular schedule, not just at closeout. Missing markups are much easier to fix while the crew that did the work is still on site.

Paper Redlines vs. Digital As-Builts

Paper redlines still work, but they have familiar problems: sheets get lost or damaged in the job trailer, handwriting made in the field is hard to read months later, markups from different trades end up on different copies, and scanned pen markups often lose detail. Consolidating several trades' paper markups onto one clean set at closeout can take days.

Digital as-builts move the same process onto PDFs. Trades mark up the current drawings on a tablet or laptop, markups can be kept on separate layers by trade so they can be reviewed individually or combined, measurement tools calibrated to the drawing scale let you add real dimensions, and the final set exports as annotated PDFs. The underlying discipline (mark up before cover-up, dimension from permanent references, cite the RFI or change order) is the same either way.

Handing Over As-Builts at Closeout

Check the spec for format. Many owners accept annotated PDFs. Some require native CAD files, which means someone has to draft the changes into the drawing files. Know which you owe before the project starts, since it affects who does the work and what it costs.

Organize by discipline. Deliver the set in the same order as the contract drawings, with a cover sheet or index and a clear label that these are as-built drawings.

Include the paper trail. Where the contract calls for it, include the RFI and change order references on the drawings so the owner can trace why things changed.

Confirm local requirements. Some jurisdictions or utility providers require as-built documentation for certain systems, such as underground utilities or fire protection, before final approval. Requirements vary, so confirm them with the authority having jurisdiction early.

Keep a copy. Store your own copy of the final as-builts with the project record. They are useful in warranty claims and on future work for the same owner.

Common As-Built Mistakes

Waiting until closeout to start the as-built set
Recording changes without dimensions, or dimensioning from temporary objects
Marking up a superseded drawing revision
Relying on the superintendent's memory instead of the drawing
Missing RFI answers and change orders that never made it onto the drawings
Delivering low-resolution scans that are hard to read

Frequently Asked Questions

What is the purpose of as-built drawings?
They give the owner an accurate record of what was built, so future maintenance, renovations, and repairs start from real conditions rather than the original design. They also document field changes in case questions come up about the work.

Who pays for as-built drawings?
On most projects, maintaining as-builts is part of the contractor's scope under the closeout requirements, so the cost is carried in the base bid. If the owner requires something beyond the specified deliverable, such as converting markups into CAD files, that may be additional scope. Check the specifications.

Are as-built drawings the same as record drawings?
Not always. As-builts are usually the contractor's marked-up drawings. Record drawings are usually a final, clean set produced from those markups, sometimes by the architect. Contracts define the terms differently, so read yours.

Do I need CAD software to create as-built drawings?
Not unless the owner requires native CAD deliverables. Most as-builts can be produced by marking up the PDF drawing set with a markup tool that supports scaled measurements.

What software do electrical contractors use to create as-built drawings?
Electrical contractors commonly mark up the PDF drawing set with a construction markup tool rather than drafting in CAD. Look for scale-aware measurement (for conduit runs and device locations), layers or colors to separate your markups from other trades, the ability to mark up on a tablet in the field, and clean PDF export for the GC. If the owner requires CAD files, confirm who will do the drafting.

Producing As-Builts Without Paper

If you want to keep the as-built set on a tablet instead of in the job trailer, AECify's as-built drawing software lets your team mark up PDF drawings with redlines, callouts, and clouds, add measurements that respect the drawing scale, organize markups on layers by trade or phase, see who made each markup and when, and export the final set as annotated PDFs for owner handover. The drawings live alongside the rest of the project record in document management, so RFIs and change orders are easy to reference from the same place.