Who Reviews Shop Drawings? Contractor, Consultant, and Supplier Responsibilities

A shop drawing may pass through several hands before a product is fabricated or installed.

The supplier prepares product information. The subcontractor confirms the proposed selection. The general contractor coordinates the submission. The architect or engineer reviews it. Other consultants may also provide comments.

Because several parties are involved, it is easy to misunderstand who is responsible for what.

One of the most important principles is that consultant review does not replace the contractor’s own review and coordination. Each participant has a different role, and the exact obligations are governed by the project’s contract documents.

This guide explains the typical responsibilities of contractors, subcontractors, suppliers, consultants, owners, and delegated design professionals during the shop drawing process.

What Is a Shop Drawing?

A shop drawing is a project-specific document that explains how a contractor, subcontractor, fabricator, supplier, or manufacturer proposes to provide part of the work.

Despite the name, a shop drawing does not always look like a traditional drawing. A submission may include:

• Fabrication drawings
• Equipment schedules
• Product data
• Performance curves
• Wiring diagrams
• Control diagrams
• Installation details
• Material samples
• Certifications
• Test reports
• Manufacturer literature
• Coordination drawings
• Design calculations

Shop drawings typically provide more product-specific or fabrication-specific information than the construction drawings.

The contract drawings and specifications establish the design requirements. The shop drawing shows the actual product, assembly, or installation proposed to meet those requirements.

Who Prepares Shop Drawings?

Shop drawings are commonly prepared by one or more of the following:

• Manufacturer
• Supplier
• Fabricator
• Trade contractor
• Subcontractor
• Specialty designer
• Professional engineer retained by a supplier or subcontractor

The preparer depends on the type of submission.

For example:

• An air-handling-unit manufacturer may prepare certified equipment selections.
• A sheet-metal contractor may prepare duct coordination drawings.
• A structural-steel fabricator may prepare steel fabrication drawings.
• A controls contractor may prepare control schematics and points lists.
• A fire-protection contractor may prepare sprinkler layout drawings.
• A curtain-wall supplier may prepare engineered system details.
• A millwork fabricator may prepare casework elevations and fabrication details.

Preparing the document does not necessarily mean that the preparer is responsible for every aspect of the project.

The supplier may understand the selected product but may not know all field conditions. The subcontractor may understand the installation but may not have coordinated every other discipline. The contractor therefore has an important role before the submission reaches the consultant.

The Typical Shop Drawing Review Workflow

A common shop drawing workflow is:

1. The supplier or fabricator prepares the submission.
2. The subcontractor reviews the proposed product or assembly.
3. The general contractor checks the submission for completeness and coordination.
4. The contractor applies its review stamp.
5. The submission is sent to the prime consultant.
6. The prime consultant distributes it to the relevant discipline consultants.
7. The consultants review the submission and provide comments.
8. The coordinated response is returned to the contractor.
9. The contractor, subcontractor, or supplier addresses the comments.
10. The submission is revised and resubmitted when required.
11. The accepted information is distributed to procurement and construction teams.

The exact routing process may vary. Some projects use construction-management software, while others use email or a document-control platform.

Regardless of the platform, there should be a clear line of communication and a controlled record of:

• What was submitted
• Who reviewed it
• Which version is current
• What comments were made
• Whether revisions are required
• Which document may be used for construction

Supplier and Manufacturer Responsibilities

The supplier or manufacturer is usually responsible for providing accurate technical information about the proposed product.

This may include:

• Correct model number
• Product dimensions
• Materials of construction
• Capacities and performance
• Pressure and temperature ratings
• Motor and electrical characteristics
• Accessories
• Control requirements
• Installation limitations
• Maintenance requirements
• Required certifications
• Applicable test data

The supplier should clearly identify the exact selection being proposed.

A generic catalogue showing ten models, four materials, and several optional accessories is not a complete project-specific selection unless the applicable information is clearly marked.

What the supplier should check

Before issuing a submission, the supplier should confirm that:

• The correct project and equipment tags are shown.
• The selected model matches the purchase request.
• Performance is based on the specified operating conditions.
• Required accessories are included.
• Product options are clearly identified.
• Irrelevant options are removed or crossed out.
• Any exceptions are disclosed.
• Drawings and schedules are internally consistent.
• The latest revision is being submitted.

What the supplier may not be able to verify

Unless specifically engaged to do so, a product supplier may not be in a position to confirm:

• Actual site dimensions
• Available ceiling space
• Coordination with other trades
• Structural support conditions
• Required access-panel locations
• Complete installation sequencing
• All contract requirements outside its supply scope

Those items normally require review by the subcontractor and general contractor.

Subcontractor Responsibilities

The subcontractor is typically the link between the supplier’s product information and the actual installation.

The subcontractor should determine whether the proposed product or assembly can be incorporated into its portion of the work.

Depending on the trade, this review may include:

• Verifying equipment tags and quantities
• Checking connection sizes
• Checking service orientation
• Confirming installation dimensions
• Confirming required accessories
• Reviewing access and maintenance clearances
• Checking compatibility with adjacent components
• Reviewing installation instructions
• Confirming that field measurements have been completed
• Coordinating with related trades
• Identifying substitutions or deviations

For mechanical work, this could mean confirming that a selected pump meets the required flow and head, uses the correct electrical service, fits within the mechanical room, and has compatible piping connections.

For electrical work, it could mean confirming ratings, fault-current requirements, enclosure types, feeder characteristics, controls interfaces, and physical space.

For architectural work, it could include dimensions, finishes, hardware, substrates, interfaces, and field conditions.

The subcontractor should not simply forward manufacturer literature without checking whether it is suitable for the project.

General Contractor Responsibilities

The general contractor normally has the central coordination role in the submission process.

The contractor’s review is not merely administrative. By submitting a shop drawing, the contractor is generally representing that it has reviewed the submission against the contract requirements and coordinated it with the work.

The exact contractual language varies, but a meaningful contractor review commonly includes the following.

1. Confirming completeness

The contractor should check that the package contains enough information for the consultant to perform a meaningful review.

This may include:

• Cover sheet
• Contractor review stamp
• Specification reference
• Equipment tag or drawing reference
• Clearly marked product selection
• Technical data
• Performance information
• Relevant drawings and details
• Certifications
• Identified deviations

2. Checking field dimensions

The contractor is generally better positioned than the consultant to verify site conditions and construction dimensions.

Examples include:

• Shaft dimensions
• Wall openings
• Ceiling heights
• Housekeeping-pad dimensions
• Existing connection locations
• Access routes
• Structural openings
• Available installation clearances

A consultant’s review of a PDF does not normally confirm that the contractor’s field measurements are correct.

3. Coordinating trades

The contractor should identify and resolve coordination issues between disciplines and subcontractors.

For example, a mechanical equipment submission may affect:

• Electrical feeders and disconnects
• BAS points
• Fire-alarm interfaces
• Structural supports
• Architectural access panels
• Plumbing drains
• Equipment pads
• Ceiling layouts
• Acoustic requirements
• Rigging and replacement routes

Comments such as “coordinate with electrical” or “coordinate with BAS” may be useful action items, but they do not replace the contractor’s responsibility to complete the coordination.

4. Confirming quantities

The contractor should verify that the correct number of products or components is being provided.

Consultants may identify obvious discrepancies, but their review should not be treated as a complete quantity takeoff.

5. Identifying deviations

Any departure from the contract documents should be disclosed clearly.

Examples include:

• Alternate manufacturer
• Different material
• Increased equipment dimensions
• Different electrical load
• Reduced performance
• Changed connection arrangement
• Alternate control sequence
• Omitted accessory

Deviations should not be hidden in a large package or left for the consultant to discover.

6. Applying the contractor review stamp

The contractor’s stamp indicates that the submission has passed through the contractor’s review process.

The stamp should not be applied automatically to documents that have not actually been checked.

A contractor review stamp commonly records:

• Contractor name
• Reviewer
• Date
• Review status
• Coordination confirmation
• Identified deviations or comments

What Does the Consultant Review?

The architect or engineer generally reviews shop drawings relevant to the portion of the work for which they are professionally responsible.

The consultant’s review usually focuses on general conformity with the design concept and the requirements shown in the contract documents.

Depending on the submission, the consultant may review:

• Product type
• Manufacturer and model
• Materials
• Scheduled capacity
• Design operating conditions
• Major dimensions
• Connection requirements
• Performance data
• Required accessories
• Design criteria
• Applicable standards
• General arrangement
• Compatibility with the intended system
• Clearly identified deviations

The consultant may also identify apparent coordination concerns. However, consultant review is not normally intended to duplicate the contractor’s complete coordination process.

What the Consultant Does Not Normally Take Responsibility For

The exact limits depend on the contract and professional obligations, but consultant review generally does not transfer responsibility for the following away from the contractor or preparer:

• Field dimensions
• Quantities
• Fabrication processes
• Construction means and methods
• Installation techniques
• Construction sequencing
• Site safety
• Coordination between trades
• Errors or omissions in the shop drawing
• Compliance with unreviewed requirements
• Deviations that were not clearly disclosed

This distinction is why many consultant review stamps use terms such as:

• Reviewed
• Reviewed as noted
• Revise and resubmit
• Reviewed for general conformity
• No exceptions taken

The wording is intended to describe a review, not an unconditional guarantee or acceptance of every detail.

Why Consultants Often Avoid the Word “Approved”

Many project teams casually refer to “approved shop drawings.” However, consultants frequently use the word “reviewed” instead.

The difference matters.

“Approved” can be misunderstood as meaning that the consultant has verified every dimension, quantity, fabrication detail, and installation condition.

That is generally not the purpose of consultant review.

A more accurate description is that the consultant reviews the submission for general conformity with the design intent and relevant contract requirements.

The project’s contract documents and review-stamp wording should always govern.

Prime Consultant Responsibilities

On a multi-disciplinary project, submissions may be routed through a prime consultant, often the architect.

The prime consultant may be responsible for:

• Receiving submissions from the contractor
• Logging the submission
• Distributing it to relevant consultants
• Monitoring the review process
• Coordinating consultant responses
• Returning a consolidated review
• Maintaining the formal communication route

For example, an air-handling-unit submission may require input from:

• Mechanical consultant
• Electrical consultant
• Structural consultant
• Controls consultant
• Architect
• Acoustic consultant

The prime consultant helps coordinate the overall response, but each discipline typically reviews the portion related to its own design responsibility.

Subconsultant Responsibilities

A subconsultant generally reviews information relevant to its discipline.

Examples include:

Mechanical consultant

• Capacity and performance
• Airflow or water flow
• Pressure requirements
• Materials
• Connections
• Accessories
• Controls intent
• Mechanical-system compatibility

Electrical consultant

• Voltage
• Phase
• Full-load current
• Motor characteristics
• Disconnect requirements
• Starter or drive requirements
• Control power
• Emergency-power requirements
• Electrical-system compatibility

Structural consultant

• Equipment weight
• Support loads
• Attachment requirements
• Openings
• Framing
• Seismic restraints
• Delegated structural components

Architect

• Appearance
• Dimensions
• Finishes
• Locations
• Access
• Coordination with rooms, walls, ceilings, and doors
• General architectural intent

Review by one discipline does not necessarily mean that every other discipline has reviewed the submission.

Delegated Design Professional Responsibilities

Some components require design by a professional engineer retained by the contractor, subcontractor, supplier, or fabricator.

Common examples may include:

• Structural steel connections
• Pre-engineered systems
• Seismic restraint systems
• Curtain walls
• Specialty supports
• Temporary works
• Certain fire-protection systems
• Proprietary structural components

This arrangement is often called delegated design.

The delegated design professional may be responsible for:

• Performing the required design
• Applying applicable codes and design criteria
• Preparing calculations
• Preparing or supervising drawings
• Sealing documents where required
• Confirming that the component design meets the specified criteria

The consultant of record may review the delegated design submission for compatibility with the overall design concept and specified design criteria.

That review does not normally make the consultant of record the designer of the delegated component.

Owner Responsibilities

The owner is usually not responsible for performing the contractor’s technical shop drawing review.

However, the owner may have responsibilities or interests related to:

• Selecting finishes or colours
• Confirming owner-supplied equipment
• Reviewing operational requirements
• Confirming maintenance preferences
• Approving substitutions with cost implications
• Reviewing schedule impacts
• Confirming long-term compatibility
• Participating in major design decisions

An owner’s acceptance of appearance, cost, or operational preferences does not replace the technical reviews performed by the contractor and consultants.

Who Is Responsible for Coordination?

Coordination is a shared process, but the contractor generally has the primary responsibility for coordinating construction, subcontractors, suppliers, dimensions, and installation requirements.

The consultant coordinates the design documents and reviews submitted information within the scope of its professional services.

These are related but different responsibilities.

Contractor coordination commonly includes

• Trade-to-trade coordination
• Field measurements
• Installation sequence
• Fabrication dimensions
• Access for construction
• Temporary conditions
• Procurement
• Supplier interfaces
• Construction means and methods

Consultant coordination commonly includes

• Coordination of design disciplines
• Design intent
• Contract-document requirements
• Design interfaces
• Consultant comments
• Changes to the design

A consultant may identify a clash during review, but the contractor should not rely on consultant review as its only clash-detection or coordination process.

Who Is Responsible When a Shop Drawing Contains an Error?

There is no single answer that applies to every situation.

Responsibility may depend on:

• Who prepared the document
• Who designed the component
• Whether the error was within a party’s scope
• What the contract says
• Whether a deviation was disclosed
• Whether the submission was properly reviewed
• Whether comments were addressed
• Whether work proceeded before review was complete
• Applicable legislation and professional obligations

A consultant’s review does not automatically make the consultant responsible for every error contained in the submission.

Similarly, a contractor’s stamp does not eliminate the responsibility of a supplier or delegated design professional for its own work.

When an actual dispute arises, the parties should refer to the project agreement and obtain appropriate professional or legal advice.

Can Work Begin Before the Shop Drawing Is Reviewed?

The contract documents should establish when shop drawings are required and whether fabrication, procurement, or installation may proceed before review.

Starting work too early creates significant risk.

Possible consequences include:

• Ordering a non-compliant product
• Fabricating incorrect components
• Rework
• Replacement costs
• Delayed construction
• Unresolved coordination conflicts
• Disputes over responsibility
• Rejected inspections

Long-lead equipment creates pressure to move quickly, but schedule pressure does not eliminate the need for a controlled review process.

The contractor should identify long-lead submissions early and include them in the submittal schedule.

What Should Happen When the Consultant Returns Comments?

The contractor should review the consultant’s response before distributing it for construction or resubmission.

The contractor should determine:

• Whether revisions are required
• Who must address each comment
• Whether another trade is affected
• Whether cost or schedule is affected
• Whether the supplier must revise its selection
• Whether a formal RFI or change process is required
• Whether the submission must be returned to the consultant

For a resubmission, the revised package should include a clear response to every previous comment.

A useful response matrix contains:

Review comment	Response	Action taken	Revised page
Confirm motor voltage	Revised to 600 V, 3-phase	Electrical data updated	Page 4
Provide access clearance	Clearance added to plan	Layout revised	Page 7
Identify filter rating	MERV 13 filter confirmed	Schedule updated	Page 3

The revised information should also be clouded, highlighted, or otherwise identified.

Common Responsibility Mistakes

Forwarding supplier documents without contractor review

This transfers an incomplete quality-control task to the consultant and often results in avoidable comments.

Assuming consultant review confirms field dimensions

The consultant usually does not have the same access to site conditions as the contractor.

Failing to disclose substitutions

A different model or manufacturer should be identified clearly, even when the supplier considers it equivalent.

Treating comments as optional

A “reviewed as noted” response still requires the contractor to incorporate and coordinate the consultant’s comments.

Proceeding using a superseded version

Only the current reviewed submission should be distributed for procurement and construction.

Assuming one consultant reviewed every discipline

A mechanical review does not necessarily confirm electrical, structural, architectural, or controls requirements.

Believing consultant review transfers all liability

Each project participant remains responsible for obligations within its own scope.

Shop Drawing Responsibility Matrix

Task	Supplier or fabricator	Subcontractor	General contractor	Consultant
Prepare product or fabrication information	Primary	May assist	No	No
Confirm exact product selection	Primary	Primary	Verify	Review relevant requirements
Confirm product technical data	Primary	Verify	Check completeness	Review design-related criteria
Verify field dimensions	Limited	Primary	Primary	Not normally
Coordinate subcontractors	No	Within own trade	Primary	Not normally
Coordinate design disciplines	No	No	Identify construction impacts	Primary within design scope
Verify quantities	Supplier scope	Primary	Primary	Not normally
Identify deviations	Primary	Primary	Primary	Review disclosed deviations
Check design intent	Support	Support	Preliminary check	Primary
Review fabrication means and methods	Primary	Primary	Primary	Not normally
Apply contractor review stamp	No	Sometimes internal	Primary	No
Provide formal consultant review status	No	No	No	Primary
Address consultant comments	Primary	Primary	Coordinate	Verify when resubmitted

This matrix is a general guide only. The contract documents govern the actual division of responsibility.

How AI Fits Into the Review Process

AI-assisted review can help contractors and project teams perform an additional check before sending a submission to the consultant.

For example, an AI-assisted review may help identify:

• Missing technical information
• Unmarked product selections
• Apparent specification mismatches
• Performance discrepancies
• Missing accessories
• Inconsistent equipment data
• Items requiring discipline coordination
• Potential deviations requiring consultant attention

AI does not take over the responsibilities of the supplier, contractor, consultant, or professional engineer.

It should be used as a quality-control aid within a properly managed review process.

Shopdrawing.AI allows project teams to upload a project specification and shop drawing package for a preliminary comparison before formal submission.

Check a Shop Drawing Before Submission

Shop Drawing Review Checklist by Role

Supplier or fabricator

• Confirm the exact product and model.
• Provide accurate technical and performance data.
• Mark all selected options.
• Include required accessories.
• Identify exceptions and deviations.
• Use the latest project information.

Subcontractor

• Confirm the product suits the intended installation.
• Check connections, orientation, and dimensions.
• Verify field conditions.
• Coordinate within the trade.
• Confirm quantities.
• Review installation requirements.

General contractor

• Confirm the submission is complete.
• Coordinate affected trades.
• Verify field dimensions and site conditions.
• Identify deviations.
• Confirm the latest contract documents were used.
• Apply a meaningful contractor review stamp.
• Track comments, revisions, and current versions.

Consultant

• Review relevant information for general conformity with the design concept and contract documents.
• Review disclosed deviations.
• Coordinate comments within the consultant team.
• Clearly communicate the review status.
• Identify required revisions within the consultant’s scope.

Frequently Asked Questions

Who is responsible for checking shop drawings?

Several parties check different aspects of a shop drawing. The supplier checks its product information, the subcontractor checks suitability for its work, the general contractor checks completeness and construction coordination, and the consultant reviews relevant information for general conformity with the design intent and contract documents.

Does the contractor have to review shop drawings before submission?

Typically, yes. The contractor is generally expected to review and coordinate shop drawings before submitting them to the consultant. The exact requirement is established by the project’s contract documents.

Does the consultant approve shop drawings?

Consultants commonly describe their action as a review rather than an approval. Their review is generally focused on conformity with the design concept and contract requirements, not every field dimension, quantity, fabrication method, or installation detail.

Who verifies shop drawing dimensions?

The contractor, subcontractor, fabricator, or other party responsible for the work is generally expected to verify field and fabrication dimensions. Consultant review should not be treated as confirmation of site measurements.

Who is responsible for shop drawing coordination?

The general contractor typically has primary responsibility for coordinating subcontractors, suppliers, field conditions, and construction interfaces. Consultants coordinate the design within their professional scopes.

Can a supplier submit a shop drawing directly to the consultant?

The required communication route should be established by the contract and project procedures. Shop drawings are commonly submitted through the general contractor so that contractor review and coordination occur before consultant review.

Does consultant review relieve the contractor of responsibility?

Generally, no. Consultant review does not normally relieve the contractor of its responsibilities for dimensions, quantities, coordination, fabrication, construction methods, errors, omissions, or compliance with the contract documents.

Who addresses shop drawing review comments?

The contractor coordinates the response. Depending on the comment, the revision may be completed by the supplier, subcontractor, fabricator, delegated design professional, or another affected trade.

Final Takeaway

Shop drawing review is not one person’s task.

The supplier, subcontractor, contractor, consultant, and delegated design professional each examine different aspects of the submission.

The contractor’s review focuses heavily on completeness, field conditions, quantities, installation, and trade coordination. The consultant’s review focuses on general conformity with the design concept and relevant contract requirements.

The process works best when those roles are understood before submissions begin.

A complete, coordinated, and clearly marked shop drawing gives the consultant the information needed to perform an efficient review—and reduces the likelihood of avoidable comments, resubmissions, procurement delays, and field conflicts.

For a practical review workflow, read our contractor checklist for reviewing shop drawings before consultant submission.

You can also review the most common reasons shop drawings get rejected.

You can also use our AI shop drawing review tool to compare a shop drawing against the applicable project specification.