A coordinated Revit model is not a shop drawing. The model shows that the trades fit. The shop drawing is the contractual submittal that says how your trade will build its part of the work. A reviewer has to accept it before you fabricate. Many MEP subcontractors find the gap at the worst time. The model is done, the set is rejected, and the fabrication date has not moved.
This guide is for MEP subcontractors and design-build contractors who prepare or buy shop drawings, especially when BIM capacity is short. It covers what a set must contain for each trade and where LOD 350 and LOD 400 sit. It also shows how the submittal and request for information (RFI) cycle runs in practice. The wider MEP design services hub covers design-phase work that comes before this stage.
Quick answer. MEP shop drawings are drawings, schedules and data a contractor or subcontractor prepares to show how it will build part of the design. Under AIA A201-2017 they are not Contract Documents, and the contractor stays responsible for coordination and accuracy even after approval. A model at LOD 350 supports coordination. LOD 400 reaches the level of shop drawings, but the sheets still need submittal procedure and review.
Sources were checked on 31 October 2026. Contract language, project specifications and local rules change the details, so the project documents control. Where this guide describes common practice rather than a source, it says so.
What is the difference between design drawings and MEP shop drawings?
Design drawings state the design intent. Shop drawings state how the contractor proposes to meet it. The two are written by different parties, carry different contract status and are reviewed for different purposes.
AIA Document A201-2017, the General Conditions of the Contract for Construction, defines Shop Drawings in section 3.12.1. They are “drawings, diagrams, schedules, and other data specially prepared for the Work by the Contractor or a Subcontractor, Sub-subcontractor, manufacturer, supplier, or distributor to illustrate some portion of the Work.” Section 3.12.4 adds that shop drawings and similar submittals are not Contract Documents. Their purpose is to show how the contractor proposes to conform to the information and design concept in the Contract Documents. We read these sections in a public copy of A201-2017 published by the University of Wisconsin System. That copy is owner-modified, so check the form your own contract uses.
| Question | Design drawings (Contract Documents) | MEP shop drawings (submittals) |
|---|---|---|
| Who prepares them | Architect and engineers of record | Contractor, subcontractor, manufacturer, supplier or fabricator |
| Contract status under A201 | Part of the Contract Documents | Not Contract Documents (A201 3.12.4) |
| What they show | Design intent, performance criteria, basis of design | Actual routing, sizes, equipment, connections, supports, field dimensions |
| Who reviews | Owner and permit authority | Contractor first, then architect or engineer for conformance |
| Reviewer’s limit | Not applicable | Conformance with design concept only (A201 4.2.7) |
| Who answers for accuracy | Design team for the design | Preparer and contractor for dimensions, quantities and coordination |
AIA Contracts says the same thing in plain terms. Its submittal explainer says the prime contractor and subcontractors prepare and furnish submittals to the architect or owner. It also says the architect reviews submittals to check conformance with the design concept, not the accuracy and completeness of details.
Practical consequence: a design model handed to a subcontractor is not a shop drawing set, even at high detail. Someone on the contractor side has to adopt it, verify it against field conditions, coordinate it with the other trades and submit it.
Who is responsible when an MEP submittal is approved?
The contractor is. Approval by the architect does not move that responsibility. This is the most misunderstood part of the cycle, and it decides how much checking a subcontractor should put in before it submits.
Read these A201-2017 sections together.
| A201 section | What it says in effect | What it means for an MEP sub |
|---|---|---|
| 3.12.5 | Contractor reviews for compliance, approves and submits, following the submittal schedule | Your set goes out only after your own review |
| 3.12.6 | Submitting is a representation that the contractor has reviewed and approved the set, verified materials and field measurements (or will), and checked and coordinated the set with the Work | Coordination is yours to prove, not the reviewer’s to find |
| 3.12.7 | No Work that requires a submittal starts until the submittal is approved | Fabrication waits for the approval stamp |
| 3.12.8 | Approval does not relieve the contractor of deviations unless they were specifically flagged at submittal and approved; approval does not relieve errors or omissions | A silent substitution stays your problem |
| 3.12.9 | Revisions on a resubmittal beyond those requested must be pointed out | Unflagged changes are not covered by the new approval |
| 4.2.7 | Architect reviews only for conformance with the design concept; review is not for the accuracy and completeness of dimensions and quantities; approval of an item is not approval of an assembly | The reviewer is not checking your dimensions or your clash resolution |
Two points matter most for MEP work. First, the line about assemblies means an approved air handler cut sheet is not an approved air handler connection. The duct, pipe and electrical connections around it need their own check, and a vendor model with unreliable connectors makes that check harder (see the manufacturer family spec checklist). Second, deviations must be flagged at submittal. If a supplier’s unit is larger than the basis of design and you route around it without saying so, approval does not cover the change.
Section 3.12.10 deals with professional design services. A contractor is not required to provide them unless the contract documents require it. Where they do, a licensed design professional signs and seals the related submittals. Whether any MEP element on your project is delegated design is a contract question. Read the specification section for that element before you assume either way.
What does each MEP trade put on its shop drawings?
Each trade submits different content to different reviewers. The table gives a working baseline. The project specification section for each trade overrides it.
| Trade | Typical shop drawing content | Standards and rules to name | Who reviews besides the design team |
|---|---|---|---|
| Ductwork | Plans and sections with duct sizes, bottom-of-duct elevations, fittings, dampers, access doors, insulation or liner, hangers and bracing references, wall and floor penetrations, equipment connections | SMACNA HVAC Duct Construction Standards, Metal and Flexible, or the standard the specification names | Commissioning and test-and-balance reviewers, where the specification involves them |
| Hydronic and plumbing pipe | Plans, risers and sections with pipe sizes, slopes for gravity lines, valves and specialties, expansion provisions, hangers, insulation, cleanout and access points, penetrations | Project specification sections; adopted plumbing and mechanical codes | Plumbing inspector at permit and inspection stage |
| Fire sprinkler | Layout plan, riser diagram, hydraulic calculations, water supply data, equipment data sheets, bracing details | NFPA 13 working plan requirements as adopted locally | The authority having jurisdiction (AHJ) reviews the plans, often separate from the architect |
| Electrical | Conduit and cable tray routing, supports, equipment room layouts, panel and switchgear elevations, pad and housekeeping slab sizes, working and dedicated space, penetrations | NEC section 110.26 for spaces about electrical equipment, in the adopted edition | Utility or AHJ for service equipment where required |
The SMACNA names matter because specifications cite them. SMACNA’s technical standards page lists the HVAC Duct Construction Standards, Metal and Flexible, 4th edition. It calls that its flagship document for sheet metal duct fabrication and installation requirements. The page also lists the Seismic Restraint Manual: Guidelines for Mechanical Systems (4th edition, 2024), the Fibrous Glass Duct Construction Standards (8th edition) and the Rectangular Industrial Duct Construction Standards (3rd edition). Which one governs your duct set depends on the duct type and the specification, so name it on the sheet.
Ductwork shop drawings
Ductwork shop drawings carry more fabrication information than any other MEP set, because sheet metal is built to the drawing. A reviewer expects duct size and elevation at every change and the fitting type. The pressure class belongs on the sheet if the specification sets one. Every damper and access door needs its clear space shown. Sizing starts from the load and airflow work. The HVAC load calculation guide explains why: a duct drawn to the wrong airflow is a clean-looking error.
In our judgement, hangers and bracing are a frequent gap. The set should say what supports each run and how the seismic or sway bracing is handled, or point to the sheet that does.
Pipe shop drawings
Pipe sets turn on slope and access. Gravity drainage cannot be rerouted freely, so common practice places it first, as the industrial MEP coordination guide shows for plant pump rooms and racks. Show valve locations with the clear space needed to operate them, and cleanouts with reach. Show insulation thickness where it changes the outside diameter that hangers and penetrations must accept.
Fire sprinkler shop drawings
Sprinkler submittals follow a different path from the rest of the MEP package. Many AHJs review the sprinkler working plans directly. The Lower Valley Fire District in Colorado is one example. Its December 2020 plan review document says working plans must go to the AHJ for review and approval before installation or other work starts. It cites the 2018 International Fire Code and the 2016 edition of NFPA 13. It asks for plans, equipment specification sheets and hydraulic calculations, and it limits the age of the water supply test to 12 months before submittal. It also requires the designer to be a Colorado registered professional engineer or hold NICET Level III or IV certification. That is one fire district, in one state, under older code editions. Your AHJ may differ, so ask for its checklist before you start.
The practical point is that a sprinkler set can pass the architect and still be held by the fire authority, or the other way round. Track the two reviews separately.
Electrical shop drawings
Electrical sets are often thinner on routing and heavier on equipment rooms. Show the layout of switchgear, panels and transformers, the housekeeping pad, the conduit stub-up locations and the clear space in front. NEC section 110.26 covers spaces about electrical equipment. According to Electrical Construction and Maintenance magazine (December 2023), 110.26(E) requires switchboards, switchgear, panelboards and motor control centers to sit in dedicated spaces. In our judgement, pipe and duct routed through those spaces is a common coordination failure. Check the section in the NEC edition your jurisdiction has adopted.
Where do LOD 350 and LOD 400 fit in a shop drawing set?
LOD 350 is the coordination level. LOD 400 is the fabrication level. A shop drawing set draws on both, but a model at either level is not the submittal by itself. The LOD 300 vs LOD 400 guide covers the definitions and procurement language. This section covers only how they map to shop drawings.
The BIMForum Level of Development Specification, Part I, Version 2025, defines LOD 350 as elements sufficiently developed to support construction-level coordination. It adds that this level usually requires craft knowledge. It describes LOD 400 as an element developed to the level of shop drawings. It says a team might model an item at LOD 400 if the project specification calls for shop drawings of it. It adds that most models contain few if any LOD 400 elements. The specification itself also says it does not prescribe the level for any project phase and does not say who should author a given element.
Those last two points are easy to miss. The specification does not say shop drawings must be at LOD 400. It does not assign the work to the designer or the contractor either. The contract does.
| System (BIMForum 2025 entry) | LOD 350 adds to LOD 300 | LOD 400 adds | Shop drawing sheet it supports |
|---|---|---|---|
| Supply air, D3060.10 | Actual size, shape, spacing, location and connections of duct, dampers, fittings and insulation; actual hangers, supports and seismic control; actual floor and wall penetrations; actual access and code clearances | Supplementary components required for fabrication and field installation | Duct layout and fabrication sheets |
| Hydronic distribution, D3050.10 | Actual size, location, connections and slope of pipe, valves, fittings and insulation; actual hangers, supports and seismic control; actual penetrations; actual access and code clearances | Supplementary components required for fabrication and field installation | Pipe layout, riser and spool sheets |
| Water-based fire suppression, D4010.10 | Actual size, location, slope and connections of pipe, valves, fittings and insulation; actual hangers, supports and bracing; actual penetrations; actual access and code clearances | Supplementary components required for fabrication and field installation | Sprinkler working plans |
| Branch wiring, D5030.10 | Actual size, spacing and location of raceways, boxes and enclosures; actual supports and seismic control; penetration elements; actual access and code clearances | Supplementary components required for fabrication and field installation | Conduit and tray layout sheets |
Read the table for what it shows. At LOD 350 the model carries actual routing, connections, supports and penetrations. That is what a coordination meeting needs. At LOD 400 the model gains the supplementary components fabrication needs. The table does not show the rest of a shop drawing. That includes schedules, product identification, notes on deviations, the submittal number and the contractor’s approval stamp. Those come from the submittal procedure, not from the model.
Our practitioner judgement, labelled as such: treat the model as the source and the sheets as a controlled extract. If a dimension on a sheet cannot be traced to the model, or the other way round, the set is not ready.
What should be coordinated before the set goes out?
Close coordination before you submit, not after. A reviewer who finds a trade conflict will usually return the set. A conflict between your sheets and another trade’s sheets is also yours to resolve. Section 3.12.6 puts coordination inside the contractor’s representation.
Work in this order.
- Start from the current backgrounds. Confirm the architectural and structural files are the latest issued set. Some owners provide the design files for use in preparing shop drawings under a data license. The University of Houston master specification, for example, refers to AIA Document C106, Digital Data Licensing Agreement, for that purpose.
- Fix the routing priority. Agree which trade moves first when space runs out. A common practice, not a code rule, is to protect gravity drainage, then large ductwork, then pressure piping, then conduit and tray. Follow the contract if it sets the order.
- Run the clash passes and close the results. Test against structure and between trades, then log each result with an owner and a status. The BIM clash detection workflow lays out the matrix, tolerances and sign-off steps.
- Check clearances separately from clashes. Access doors, valve reach, equipment working space and maintenance zones do not always show as geometric clashes. Model them or mark them on the sheet.
- Verify field conditions. Section 3.12.6 includes field measurements and field construction criteria. Mark dimensions taken from the field and note any existing conditions you could not confirm.
- Get each trade to sign the combined result. Record that the duct, pipe, sprinkler and electrical leads each accepted the same federated model on the same date.
If your own team is short of Revit hours for this stage, MEP BIM modeling is the point of need. Heaven Designs describes that service as discipline models for mechanical, electrical, plumbing and fire protection to an agreed LOD. The page lists federated coordination with architecture and structure, sheet extraction from the live model, schedules, model QA, progress models and revision cycles. The service page also states that most design coordination work sits at LOD 200 to 350, with higher LODs available when scope and inputs support them. It does not list stamped or approved shop drawings as a deliverable. Ask what sheet extraction covers on your job before you rely on it for a submittal.
How does the MEP submittal and RFI workflow run?
The submittal loop is a controlled exchange with a set order. The project specification, usually in Division 01, writes the rules. The Construction Specifications Institute (CSI) MasterFormat numbers that section 01 33 00, Submittal Procedures. The MasterFormat 2018 Applications Guide describes it as the administrative and procedural requirements for processing submittals during the construction stage. We read the section titles in a copy of that guide hosted by the Associated General Contractors of Austin.
The same guide lists section 01 26 13 as Requests for Information, with RFI also glossed as request for interpretation.
To see what such a section contains, we read two public owner specifications. The University of Houston master specification (revised January 2018) and the Chicago Public Schools version (December 2011) are templates, not your contract. They show the common shape.
- Build the submittal schedule. The Houston template asks for a schedule in chronological order by the dates the construction schedule requires. It tells the contractor to include review time, ordering, manufacturing, fabrication and delivery, and extra time for corrections.
- Prepare the package. Shop drawings are project-specific and drawn to scale. They should not be reproductions of the Contract Documents. The Houston template lists product identification, schedules and compliance with specified standards. It also lists coordination notes, field-measured dimensions and the relationship to adjoining construction.
- Review and stamp internally. Both templates require the contractor to review each submittal for coordination and compliance and to note field dimensions. The contractor applies an approval stamp before the set goes to the architect.
- Submit by the numbers. Use the specification section number and a sequential number, with a suffix for resubmittals. The Houston template shows the pattern 061000.01, then 061000.01.A.
- Architect action. The reviewer marks the set and returns it with an action stamp. The Houston template has the architect return an annotated PDF, so a PDF markup tool is part of most workflows. Houston allows 15 days for an initial review. Chicago Public Schools allows 10 working days. Those are owner choices, so read your own specification.
- Resubmit or release. Resubmittals show the date and content of the prior submittal and the extent of the revision. Only sets marked approved may be used for construction.
Chicago’s template spells out five action stamps. The table translates each into what the subcontractor does next.
| Action stamp (CPS template wording) | Template meaning | Subcontractor response |
|---|---|---|
| Reviewed: No Exceptions Taken | No further review; work may proceed if it complies with the Contract Documents | Release to fabrication |
| Reviewed: Make Corrections Noted | Incorporate corrections; resubmittal not required | Fix, release, and keep the marked copy on file |
| Rejected: Revise and Resubmit | Deficient or in conflict with Contract Documents; work may not proceed | Revise as noted, flag every change, resubmit |
| Rejected: Not Acceptable for Review | Deficient or in conflict, and not reviewed | Prepare a new submittal |
| Received for Record Only | Not reviewed | File it; no approval exists |
Where do RFIs fit?
An RFI is a question, not a submittal. Use it when the Contract Documents leave a conflict, gap or ambiguity that you cannot resolve by coordination alone. A201 section 3.2.2 expects the contractor to report errors, inconsistencies or omissions as a request for information. The architect or owner sets the form. Section 4.2.14 says the architect will review and respond to such requests.
Practitioner rule of thumb: if the question is about what the design intends, send an RFI. If the question is about how you will build it, put the answer in the submittal and flag any departure. Do not bury a deviation in a drawing and wait to see whether anyone notices. Section 3.12.8 puts that risk on the contractor.
Why are fire sprinkler submittals handled separately?
The architect’s review is a conformance check against the design concept. The AHJ’s review is a code review of the working plans. They answer different questions and can run in parallel. Ask the fire authority for its submittal checklist at the start, because AHJs set their own requirements, including edition, designer qualification and calculation inputs (the sprinkler hydraulic calculation guide lists them).
How do you back-schedule one MEP submittal?
Start from the date the item must be on site and count backward through every step the item needs. The example below is illustrative. Every duration is an assumption chosen for the illustration, not a norm.
Assumptions: one air handling unit. Delivery takes six weeks and fabrication four. Each architect review takes two weeks. The contractor’s own review takes one week, a resubmittal takes one week to prepare, and the first set takes three. One cycle is rejected before approval.
| Step | Duration (weeks) | Weeks before required on site |
|---|---|---|
| Delivery | 6 | 6 to 0 |
| Fabrication | 4 | 10 to 6 |
| Approval needed by this point | 0 | 10 |
| Second architect review | 2 | 12 to 10 |
| Resubmittal preparation | 1 | 13 to 12 |
| First architect review (returned) | 2 | 15 to 13 |
| Contractor review and stamp | 1 | 16 to 15 |
| Prepare first set | 3 | 19 to 16 |
The first drawing work starts 19 weeks before the item is needed. If the schedule shows only 12 weeks, either the review cycle must shrink or the date must move. Section 3.12.5 ties submittals to an approved submittal schedule for this reason. AIA Contracts advises setting one early if the contract is silent.
Why do MEP shop drawings get rejected?
Most returns come from a short list of avoidable causes. No source publishes a reliable rejection rate for MEP sets, and we do not offer one. The list below is practitioner judgement, built from how the A201 duties and the sample specifications read.
- Not coordinated. The reviewer finds a conflict with another trade or with structure.
- Incomplete package. The set is missing schedules, calculations or cut sheets. The Chicago template says the architect will not review submittals that are incomplete, contain numerous errors or appear to be checked only superficially. The Houston template says incomplete submittals are returned without review.
- Unflagged deviation. The set uses a different product, size or route than the design and does not say so (A201 3.12.8).
- Equipment does not match. Routing was drawn to the basis-of-design unit, but the submitted unit has different connections, weight or clearances.
- Product options not marked. The Houston template requires each copy to show which products and options apply. A cut sheet listing five models without a mark is returned.
- Unverified field dimensions. Existing conditions were assumed, not measured (A201 3.12.6).
- Changes hidden in a resubmittal. Revisions beyond the reviewer’s comments are not called out (A201 3.12.9).
- Stale backgrounds. The set sits on a superseded architectural or structural issue.
- Weak identification. Sheets lack the specification section, submittal number or revision suffix, so the log and the set cannot be matched.
- Missing access and clearance. Doors, valves and equipment have no maintenance space, or electrical equipment has pipe or duct in its dedicated zone.
What should be on a pre-submittal checklist for each trade?
Use this as a gate. A set that cannot pass every line for its trade is not ready to stamp. These are working checks drawn from the sources above and common practice. Add the items your specification names.
All trades
- Submittal number, specification section, project name and revision suffix on every sheet.
- Contractor review and approval stamp, signed and dated.
- Deviation sheet listing every departure from the Contract Documents, or a statement that there are none.
- Backgrounds match the current architectural and structural issue, with the issue date noted.
- Field-measured dimensions marked as such.
- Coordination sign-off recorded for the federated model used.
- On a resubmittal, every revision beyond the reviewer’s comments called out.
Ductwork
- Sizes, bottom-of-duct elevations and fitting types at every change.
- Pressure class and construction standard named as the specification requires.
- Dampers and access doors located with clear space.
- Insulation or liner type and thickness shown.
- Hangers and bracing shown or referenced to a sheet.
- Penetrations dimensioned, with sleeve and fire-rated assembly notes.
- Equipment connections match the submitted unit, not only the basis of design.
Hydronic and plumbing pipe
- Sizes, materials and slopes for gravity lines.
- Valve and cleanout locations with operating clearance.
- Hangers and supports shown at spacing the specification requires.
- Insulation thickness reflected in hanger and penetration details.
- Penetrations and expansion provisions located.
- Equipment connections match the submitted unit.
Fire sprinkler
- Working plans, hydraulic calculations and equipment data sheets together.
- Water supply data and test date meet the AHJ’s age rule.
- Edition of NFPA 13 matches what the AHJ has adopted.
- Designer qualification meets the AHJ’s rule.
- Riser diagram and bracing details included.
- AHJ submittal tracked separately from the architect’s.
Electrical
- Raceway and tray routes, sizes and supports shown.
- Equipment room layout with working space and dedicated space marked, checked against NEC 110.26 in the adopted edition.
- Pad and housekeeping slab sizes and stub-up locations.
- No foreign piping or ductwork in dedicated equipment space.
- Penetrations located and fire-rated assemblies noted.
- Panel and switchgear elevations match the submitted equipment.
When does it make sense to add BIM capacity for shop drawings?
Add capacity when the model has to carry detail that the submittal will draw from, and your own team cannot produce it on time. Typical triggers are a late model drop, several trades needing LOD 350 coordination in the same window, or a set of resubmittals arriving together.
Before you hire anyone, settle three points in writing. First, who authors which elements and at what LOD, since the BIMForum specification leaves that to the project. Second, who reviews and signs the sheets, because the contractor’s representation in A201 3.12.6 does not transfer. Third, what the provider will and will not deliver. A model, a set of extracted sheets and an approved submittal are three different things. The MEP design outsourcing guide covers vendor selection, handoff and contract controls in more depth.
FAQ
Are shop drawings part of the contract documents?
Not under A201-2017. Section 3.12.4 says shop drawings, product data, samples and similar submittals are not Contract Documents. Their purpose is to show how the contractor proposes to conform to the design.
Does LOD 400 mean I get shop drawings?
Not automatically. BIMForum describes LOD 400 as the level of shop drawings for a modeled element. Sheets, schedules, identification and the approval stamp still come from the submittal procedure. Name each required sheet in the scope.
Who approves an MEP shop drawing?
The contractor reviews and approves first, then the architect or engineer reviews for conformance with the design concept. Fire sprinkler plans commonly go to the AHJ as well. Reviewers do not check the accuracy of your dimensions or quantities under A201 4.2.7.
How long does a submittal review take?
It depends on the specification. Two public templates differ, with 15 days in the University of Houston master specification and 10 working days in the Chicago Public Schools version. Read the Division 01 section for your project and plan for resubmittals.
What is the difference between an RFI and a submittal?
An RFI asks a question about the Contract Documents. A submittal shows how you propose to build. Use an RFI for a design conflict or gap, and flag any departure in the submittal itself.
Do ductwork shop drawings have to follow SMACNA standards?
Only if the specification or adopted code requires it. SMACNA publishes the HVAC Duct Construction Standards, Metal and Flexible, and related duct and seismic documents. The specification names the one that governs your duct type, so cite it on the sheet.
Can the same model produce coordination drawings and shop drawings?
Often, yes, if the model is built and controlled for both uses. The model needs actual routing, supports and penetrations, and every extracted sheet must trace to the model version that was coordinated.
Choose the next step before the next set is due
If a set is due and your team lacks the Revit hours, start with the checklist above and a written scope for who models what. Then review the MEP BIM modeling service page to see whether its listed deliverables match your coordination needs. Use our contact page to describe the project. Scope, LOD and review path are agreed at scoping. For a related control, the ASHRAE 90.1 compliance drawings guide covers keeping the permit report, issued drawings and submittal log on one approved basis.