What are Shop Drawings in Construction? An Owner’s Guide

Shop drawings are one of the most misunderstood documents on a construction project. Owners often see the term in a contract and assume it means the same thing as the architect’s plans. It doesn’t.

This guide walks through what shop drawings actually are, how the review process works, who is legally responsible when something goes wrong, and what happens to them once the project closes out.

What Are Shop Drawings? Common Examples by Trade

Shop drawings are detailed drawings prepared by a contractor, subcontractor, or supplier. They show exactly how a specific piece of work will be fabricated and installed. These are not the architect’s original design drawings. Shop drawings are the trade’s translation of that design into buildable and/or manufacturable detail.

The architect’s drawings might show a steel beam as a single line on a structural plan. The structural steel shop drawing shows the exact beam size, every bolt hole, every connection plate. They may also show every weld location needed to fabricate that beam in a shop.

Shop drawings show up across nearly every trade on a project. Common examples include:

• Structural steel: beam sizes, connection details, bolt patterns, and erection sequencing for the steel fabricator.
• Wood trusses: engineered layouts showing truss spacing, bearing points, and load paths for the truss manufacturer.
• Roofing: flashing details, membrane layouts, and drainage patterns specific to the roof system chosen.
• Millwork: cabinet and casework dimensions, joinery details, and finish specifications built to the actual field conditions.
• MEP (mechanical, electrical, plumbing): ductwork routing, conduit layouts, schematics, and pipe sizing coordinated around the building’s actual structure.
• Flooring: transition details, expansion joint layouts, and pattern orientation for the specific product ordered.
• Wallcovering: seam locations, pattern matching, and material takeoffs tailored to the actual wall dimensions.

Each of these documents is produced after the contract is signed. They translate a general design intent into something a fabricator or installer can actually build from.

How Shop Drawings Fit Into a Larger Submittal Package

Shop drawings are only one piece of what a contract typically requires from a contractor. The broader category is called a submittal, and it usually includes three types of documents.

• Shop drawings: the fabrication and installation drawings described above.
• Product data: manufacturer’s catalog sheets, spec sheets, and performance data for a standard product.
• Samples: physical pieces of a material, like a paint swatch or a tile sample, submitted for approval.

Owners sometimes assume “submittal” and “shop drawing” mean the same thing. They don’t. A submittal is the umbrella term, and shop drawings are the most detailed and often the most consequential type underneath it.

How the Shop Drawing Review Process Works

Most construction contracts follow a similar review sequence for shop drawings, even though exact timeframes vary by contract.

• The contractor or subcontractor prepares the shop drawing based on the approved contract documents.
• The general contractor reviews it first, checking for coordination with other trades before it goes further.
• The general contractor formally submits it to the architect or engineer for review.
• The design professional reviews it within a set window, commonly 10 to 15 business days for standard industry specifications.
• The design professional returns it marked with one of several outcomes, ranging from “reviewed” or “accepted” to a full “revise and resubmit”.

That last outcome matters most for owners to understand. When a design professional marks a submittal “revise and resubmit,” the contractor must correct it and send it through the entire review cycle again. Each resubmittal typically gets its own full review window, often another 10 to 15 days.

This is where schedule impacts creep in. A single revise-and-resubmit cycle on a critical item can add two to three weeks to a schedule. If that item is on the project’s critical path, the entire completion date can shift.

Why Shop Drawings Must Be Submitted Well Before the Material Is Needed

Shop drawing review takes time, and fabrication takes more time after that. Contracts typically require the contractor to build a full submittal schedule at the start of the project. They will list when each shop drawing must be submitted relative to when that material needs to arrive on site.

Real World Example:

An owner is building a custom home with imported tile flooring. The tile supplier needs approved shop drawings showing the layout and pattern before cutting begins, and cutting takes six weeks.

If the flooring contractor waits until framing is finished to submit those drawings, the review window plus a revise-and-resubmit cycle plus six to ten weeks of fabrication can easily push flooring installation back by a few months. The owner’s move-in date slips, even though nothing about the actual construction work changed.

This is why an experienced contractor pushes shop drawings for long-lead items early, often before other, more visible work has even started. An owner who sees a contractor requesting approvals in the first weeks of a project should understand this is normal, and expected.

Who Pays for Materials Before Shop Drawings Are Approved

Most contracts allow a contractor to bill an owner for materials or equipment before that item is installed. This is common for expensive, long-lead equipment that must be ordered months in advance. The catch is timing relative to shop drawing approval.

Standard contract language ties payment for stored materials to an approved submittal. The contractor typically must show proof of purchase, proof of insurance, and often an approved shop drawing before the owner is required to pay. Without an approved submittal, the contractor is usually ordering and purchasing at its own risk.

Long-lead items complicate this. Custom mechanical equipment, elevators, and specialty windows can take six months or more to manufacture. Waiting for full shop drawing approval before ordering can blow the schedule before construction even begins.

Because of this, some contracts allow a deposit to secure a manufacturing slot before the full shop drawing is even submitted. This deposit is a separate, smaller commitment than the full stored-materials payment tied to final approval. Owners should understand the difference between the two, since they carry different levels of risk.

Real World Example:

An owner is building a restaurant with a custom walk-in cooler. The manufacturer needs a 40 percent deposit to reserve a build slot, four months before the shop drawing is even finalized. The owner pays the deposit based on a preliminary spec sheet, not an approved shop drawing.

Full payment is withheld until the completed shop drawing is reviewed and the unit ships. This structure protects the owner from paying in full for a unit that hasn’t been verified against the actual kitchen layout, while still letting the contractor secure the long lead time needed.

Why Shop Drawings Are Not Part of the Legal Construction Documents

This surprises most owners. Shop drawings are not part of the Contract Documents, even after they’re approved. The AIA A201 general conditions, one of the most widely used construction contract forms, states this directly.

The Contract Documents are the agreement, the drawings, and the specifications signed at the start of the project. Shop drawings come later, and they cannot change what those original documents require. If a shop drawing conflicts with the contract drawings or specifications, the original contract documents still control, even if the design professional missed the conflict during review.

This matters because owners sometimes assume an approved shop drawing locks in a change. It doesn’t, on its own. Any real change to scope, cost, or design still needs a formal change order to be enforceable.

Why Design Professionals Disclaim Full Responsibility for Shop Drawings

Shop drawings are prepared by the contractor’s team, not the architect or engineer. The design professional’s contract only requires a review, not a re-design. That distinction is deliberate, and it’s baked into most standard-form construction contracts.

Common form contracts like AIA A201 and EJCDC state that the design professional’s review is only for conformance with the “design concept” expressed in the contract documents. It is explicitly not a check of every dimension, quantity, or fabrication detail. That responsibility stays with the trade contractor who prepared the shop drawing.

“Design concept” is a deliberately broad, somewhat undefined industry term. It generally means the design professional is checking that the shop drawing matches the intended look, function, and general approach shown in the original design. It does not mean verifying every field measurement or manufacturing tolerance. Courts and industry commentators have criticized the phrase for being too vague, but it remains standard language across most major contract forms.

Why the Designer’s Stamp Says “Reviewed,” Not “Approved”

Owners often see a shop drawing marked “Reviewed” or “No Exceptions Taken” and assume it means the same thing as “Approved.” It doesn’t, and the wording is intentional.

Through the 1970s, design professionals commonly stamped submittals “Approved.” Professional liability insurers pushed a change after a string of costly claims, and the industry shifted toward softer language like “Reviewed” or “Revise and Resubmit.” The goal was to signal a limited check, not a full guarantee that the drawing was error-free.

Real World Example:

This distinction was tested, and found wanting, in one of construction’s most well-known failures. In 1979, a fabricator proposed a last-minute change to a walkway hanger connection at the Hyatt Regency in Kansas City. The engineer of record stamped the revised shop drawing “reviewed” without re-running the load calculations for the new configuration.

The change doubled the load on the connection. Two elevated walkways collapsed in 1981, killing 114 people. Courts and licensing boards later held the engineers professionally responsible, ruling that a review stamp still carries a duty to actually check the work. This is even when contract language limits that review to general design conformance. The case remains a standard reference point for why “reviewed” is not a rubber stamp, on either side of the relationship.

Trade Contractor Shop Drawings vs. Design Professional’s Own Details

There’s an important difference between a shop drawing a contractor produces and a “typical” detail a design professional draws and stamps directly. Understanding which is which affects who carries liability if something fails.

• Trade contractor shop drawings: prepared by the contractor, subcontractor, or fabricator, then reviewed by the design professional for general conformance only.
• Design professional’s own details: drawn and stamped directly by the architect or engineer, who bears direct responsibility for their accuracy. Even though even a stamped detail can fail if it doesn’t match actual field conditions.

When a trade contractor’s shop drawing fails, responsibility is usually shared and fact-specific. The contractor bears responsibility for fabrication errors, incorrect field measurements, and any deviations not flagged to the design professional in writing.

The design professional can still bear responsibility for missing an obvious design conflict during its review, as the Hyatt Regency case showed. A “reviewed” stamp limits the design professional’s scope, but it does not eliminate their duty to actually look.

Even a design professional’s own stamped detail isn’t immune from failure. If a “typical” detail doesn’t account for actual field conditions, the design professional can end up directly liable, sometimes in litigation, when the contractor builds to it “as designed”.

What Happens When Shop Drawings Are Wrong

Shop drawing errors happen for several different reasons, and each one tends to point to a different party. Understanding the pattern helps an owner know where to look when something goes wrong on site.

• Incorrect field dimensions: usually the contractor or trade’s responsibility, since verifying field measurements is part of preparing the shop drawing.
• Lack of trade coordination: often the general contractor’s responsibility, since coordinating between trades is a core part of its role.
• Unapproved material substitutions: the contractor’s responsibility if not disclosed in writing at submittal processing, as most contracts require.
• Code or safety violations: shared responsibility, but the design professional’s review should have caught an obvious code conflict.
• Vague review stamps: the design professional’s exposure grows when a stamp is unclear about what was actually checked.
• Premature fabrication: the contractor’s responsibility, since building from an unapproved or still-under-review drawing is a known risk it accepted.

Owners are rarely directly responsible for these errors. Their exposure usually comes indirectly, through schedule delays or added costs the contract allows the contractor to pass through when the error wasn’t the contractor’s fault.

Real World Example:

A contractor submits shop drawings for custom kitchen millwork based on dimensions taken before the drywall was installed. The drywall adds thickness the drawings didn’t account for.

The cabinets arrive and don’t fit. Because the contractor is contractually responsible for verifying field conditions before fabrication, the rework cost typically falls on the contractor. It’s not the owner, even though the shop drawing carried a “reviewed” stamp from the architect.

Why Shop Drawings Are Often Overlooked in Owner-Contractor Contracts

Standard form language on shop drawings, like AIA A201, is written primarily to govern the relationship between the contractor and the design professional. Many owner-contractor agreements, especially smaller residential or commercial contracts, are drafted without that level of detail.

This leaves gaps. An owner-contractor agreement might never define who pays for a shop drawing delay, what happens after a “revise-and-resubmit” cycle, or whether the owner even has a right to see shop drawings before they’re approved. Without that language, disputes over schedule impact or added cost default to general contract interpretation. This favors whichever party’s position is better documented.

Owners working from a simpler contract should ask their contractor directly how shop drawing review and approval will be handled. Getting that answer in writing, even as a short added clause, closes a gap that standard boilerplate often leaves open.

Are Shop Drawings Archived as Part of Project Closeout?

Yes. Approved shop drawings don’t disappear once installation is finished. They typically become part of the project’s closeout package, alongside as-built drawings and operations manuals.

As-built drawings, sometimes called record drawings, document how the project was actually built rather than how it was originally designed. Standard closeout specifications require these to incorporate shop drawing information. This is important particularly for concealed work like MEP systems that would otherwise be difficult to locate later.

It makes the shop drawing archive genuinely useful after move-in. A future contractor doing renovation or repair work can reference the approved shop drawings to understand exactly how a system was fabricated and installed. They may not need to open up finished walls to find out.

Owners should confirm their closeout package includes this documentation. It’s easy for shop drawings to get lost in email threads during construction if no one is specifically tracking them for the final handover.

Shop drawings translate a design into something buildable. They are reviewed, not approved, and they never override the signed contract documents. Understanding who prepares them, who reviews them, and who carries responsibility when they’re wrong protects an owner from assuming more legal cover exists than actually does.

Shop drawing and submittal review requirements vary by contract form and jurisdiction. Always review the specific language in your agreement before relying on the general process patterns described here.