Managing As-Built Drawings Through Project Closeout

What are as-built drawings?

As-built drawings are a record of what was actually built. They document deviations from the design drawings, field conditions that were discovered during construction, changes that were made as RFIs were resolved, and the final locations of all building systems as they were left when the contractor demobilized.

On the day of substantial completion, as-builts feel like paperwork. The project is essentially done. There's no value visible. Getting contractors to produce accurate as-builts is a constant battle. Contractors want to move on to the next job. The as-built drawings take time, and the value won't be obvious until months or years later.

But that value is real. In year 1, when facilities staff need to locate a valve in the MEP system or understand the final layout of the electrical panelboards, accurate as-builts answer the question immediately. In year 2, when a renovation is planned and the design team needs to understand what was built, the as-builts save weeks of investigation. In year 5, when a component fails and the equipment manufacturer needs to know the installation details, the as-builts are the only record that exists.

Buildings last 50+ years. As-built drawings last the entire life of the building. They're worth getting right.

What should as-built drawings document?

As-builts should document every deviation from the design drawings, including RFI answers, field changes, and the final locations of building systems after the contractor demobilized.

Deviations from Design

As construction progresses, changes happen. An RFI answers a question about the design. A contractor proposes a deviation because the original design doesn't work in the field. A change order modifies the scope. All of these create differences between what was designed and what was built.

As-builts need to show these deviations. If the structural engineer designed a beam at a certain elevation but the contractor had to relocate it 6 inches due to a field condition, the as-built shows the relocated beam location. If the architectural design specified a wall in one location but the wall was moved during construction, the as-built shows the moved wall.

Without these deviations documented, the as-builts look like the original design. Someone later thinks the building was built exactly as designed, when in fact there were significant changes. This creates problems when renovations are planned or when troubleshooting a building system.

Final Equipment and Component Locations

The location of mechanical equipment, electrical panelboards, fire extinguishers, exit signs, and other components shown on as-builts may differ slightly from the design drawings due to field coordination. A rooftop HVAC unit designed at one location may be installed 10 feet away due to structural conflicts that weren't caught in design. A main electrical panel may be relocated due to MEP coordination issues.

These final locations need to be documented on as-builts so the facility manager knows where to look when that equipment needs service or replacement.

Final Dimensions and Elevations

Ceiling heights, floor elevations, wall locations, and other dimensions may be discovered to be slightly different from the design during construction. Maybe the concrete slab was poured 1 inch higher in one area. Maybe a wall was built 3 inches off from where it was designed. These small differences matter when future work needs to be planned.

The design drawings were based on assumptions. The as-builts document what was actually built, and that's what matters for future work.

MEP System Final Routing and Details

The final routing of ductwork, electrical conduit, plumbing lines, and cable trays often differs from the design due to field clashes and coordination changes. As-builts need to show the final routing so maintenance personnel can find systems and renovation planners can understand what exists.

Additionally, valve locations, disconnect switches, equipment connections, and other details that were left to field coordination need to be documented on as-builts. When the chiller needs to be serviced, the maintenance team needs to know where the isolation valves are located. Without as-builts showing these details, the team has to explore the ceiling or mechanical room to find them, wasting time and potentially damaging finishes.

Field Conditions and Unforeseen Circumstances

Unforeseen conditions discovered during construction, underground obstructions, structural damage, utility conflicts, often result in changes to the design. As-builts need to document what was discovered and how it was addressed.

For example, if the excavation uncovered an old utility line that wasn't on the utility locates and the foundation had to be redesigned around it, the as-built shows where that utility is located. When future excavation is planned, that information is invaluable.

What is the most practical way to track as-built changes during construction?

The most practical way to track as-built changes during construction is to have field personnel mark up a set of field prints as work progresses.

Setting Up a Markup System

The most practical way to manage as-built information is to have field personnel mark up construction drawings as the project progresses. A set of "field prints" (physical or PDF copies of the design drawings) are used in the field, and changes are marked on them as they happen.

A good markup system includes:

• Clear marking conventions: Different colors or symbols for different types of changes (dimensions in blue, relocations in red, etc.)
• Dated and initialed marks: So it's clear when the change occurred and who observed it
• Reference to RFIs or change orders: Connecting field markups to the corresponding documentation
• Assignment by trade: Each trade responsible for marking their own as-built information (framing on structural prints, mechanical systems on MEP prints)

The advantage of this system is that changes are documented as they happen, not reconstructed after the fact. The superintendent, foreman, and trade contractors all have visibility of what changed and why.

Responsibility by Trade

Each trade should be responsible for the as-built information relevant to their scope. The structural contractor marks structural deviations. The mechanical contractor marks MEP routing. The electrical contractor marks circuit locations and equipment connections.

This is typically addressed in the contract documents with a requirement that each trade maintain marked-up sets of drawings showing their final work. At project closeout, these marked-up sets are collected and transferred to the design team or owner.

The challenge: contractors often don't prioritize this task. They see marking up drawings as extra work that doesn't directly affect their deliverables or their payment. GCs have to actively manage the process and incentivize compliance.

What is the most common failure in as-built documentation?

The most common as-built failure is contractors submitting unmarked design drawings and calling them as-builts, as if the field matched the design exactly.

Unmarked Prints Submitted as As-Builts

The most common failure: contractors submit unmarked design drawings as "as-builts." They claim they built exactly to the design, so no markups were needed. But nearly every project has some deviations, changes, and field adjustments. If the submitted as-builts are unmarked, either the contractor didn't actually follow the design (and didn't document the deviations) or they didn't do the work required to produce accurate as-builts.

Incomplete Trade-Specific Information

General contractors may mark up the architectural and structural drawings but fail to collect detailed as-built information from MEP subcontractors. The MEP contractor has the most complex coordination challenges, yet often produces unmarked prints.

Vague or Illegible Markups

Handwritten markups that are unclear or vague don't become useful as-builts. "Relocated 3 ft" is insufficient if it doesn't say in which direction or from which reference. Illegible handwriting makes the markup useless.

Lack of Reference to Documentation

A markup showing a change should reference the RFI, change order, or submittals that authorized or documented that change. Without that connection, future users of the as-builts can't understand the context of the change.

Delays in Transfer to Record Drawings

Marked-up field prints are often collected at project closeout but never transferred to clean CAD drawings or PDF record documents. The marked-up prints sit in a storage box. They're difficult to read, hard to navigate, and essentially unusable for anyone except the people who lived through the project.

What is the ideal format for as-built drawings?

The ideal as-builts are in CAD format such as AutoCAD or Revit, so later renovations can search and update a clean record of what was built.

Digital CAD As-Builts

The ideal as-builts are in CAD format (AutoCAD, Revit, or similar). Changes are incorporated into new drawing files, creating a clean, searchable, up-to-date record of what was built. Digital as-builts can be updated easily for future renovations or expansions.

The challenge: creating digital as-builts requires a designer or CAD operator to process field markups and redraw modified details. This is expensive and time-consuming. For large projects, it may take weeks or months after closeout to complete digital as-builts.

PDF As-Builts

PDF as-builts are marked-up design drawings saved as PDFs, either scanned from marked-up prints or marked up digitally on PDF files. They're faster and cheaper to produce than digital CAD as-builts.

The limitation: PDFs are static documents. They can't be easily updated. They don't have the searchability or layer organization of CAD files. But they're better than unmarked prints and much easier to share with facilities personnel or future designers.

Practical Approach

Most projects use a hybrid approach: marked-up field prints are collected and scanned. The scans are provided to the owner as PDF as-builts. Significant changes or the most important drawings (MEP systems, for example) are redrawn in CAD to create clean digital versions for long-term storage and future use.

What as-built requirements should owners put in the contract?

Smart owners include specific as-built requirements in the contract documents:

• Marked-up prints collected by trade and submitted at substantial completion
• Clear markup conventions (colors, symbols, legend) specified in advance
• Markups tied to change orders, RFIs, or submittals with specific references
• MEP systems shown in detail, including valve locations, equipment connections, and final routing
• Digital CAD as-builts required for MEP systems (due to their complexity) and architectural plans (for future renovations)
• Timeline specified for completion of digital as-builts (e.g., within 30 days of substantial completion)
• Responsibilities defined: which contractor is responsible for which portions of the as-builts

These requirements need to be in the owner-contractor agreement and subcontract documents so all parties understand the expectation.

When does the value of as-builts become obvious?

The value of as-builts becomes obvious when the building enters a renovation or expansion phase. If accurate as-builts exist, the designer for the renovation can understand what was actually built and design new work that coordinates with existing systems.

Without as-builts, the designer has to use the original design drawings (which may be inaccurate) or conduct extensive field investigation (which is expensive and time-consuming). This often leads to RFIs during the renovation phase asking what the actual building conditions are.

A renovation project with accurate as-builts available can start with a clear understanding of what exists. The design can incorporate that information, reducing RFIs and construction changes during the renovation.

Are accurate as-built drawings just a closeout formality?

Accurate as-built drawings are an investment in the building's 50-year life, not a closeout formality. They're an essential resource for the 50-year life of the building. Owners who prioritize as-builts during construction, and contractors who take the responsibility seriously, create documents that prevent problems, reduce future costs, and make the building easier to maintain and modify.

The cost of producing good as-builts is small relative to the overall project cost. The cost of not having them becomes apparent the first time the building needs work and no one knows what's actually installed.

As-Built Drawings FAQ

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