From 2D Drawings to a 3D Revit Model: The HVAC Shop Drawing Workflow
Solusi Karya Nusantara Technical Team · 2026-10-22 · 5 min read
Project owners often treat HVAC design drawings and shop drawings as the same thing, but the two serve different purposes. A design drawing shows the general system concept, while a shop drawing is the working drawing installers use to actually install ducting and piping on site, complete with sizes, elevations, and connection details that have already been coordinated. Producing shop drawings directly from a 3D Revit model, rather than from standalone 2D drawings, makes these working drawings far more reliable once installation begins.
The Difference Between a Design Drawing and a Shop Drawing
A design drawing is usually produced early in a project to show system capacity, the main ducting and piping routes, and the general position of indoor and outdoor units. This drawing is enough for permitting purposes, early estimates, and concept coordination with the project owner or other consultants.
A shop drawing sits one stage further along. It carries the actual duct and pipe sizes, the exact elevation at every point, connection and hanger details, and the results of coordination with the structural, plumbing, and electrical disciplines. This is the drawing installers actually work from on site, not the initial design drawing. Without this stage, installers often end up adjusting routes themselves during installation, which risks clashing with other systems.
The HVAC Shop Drawing Workflow in Revit
1. Gathering 2D Drawings and the Architectural-Structural Model
The process starts by gathering the existing 2D CAD drawings — the architectural layout, structural plans, and the initial HVAC design drawings — as a reference. If the architectural and structural models from other consultants are already available in Revit format, those models are used directly as linked models, giving far more accurate coordination than working from 2D drawings alone.
2. Setting Up the Revit Project and Levels
Once the data is gathered, the Revit project file is set up with floor levels, column grids, and a scale that follows the architectural-structural drawings. This stage ensures the HVAC model to be built sits at the correct position and height relative to the building.
3. Modeling Ducting, Piping, and Units
Ducting, refrigerant piping, indoor and outdoor units, and other mechanical equipment are modeled as 3D objects according to the capacity and layout already planned in the design drawing. Each element is built with its actual size and elevation, not just a representative line as on a 2D drawing.
4. Coordination and Clash Checking
The HVAC model is combined with the structural, plumbing, and electrical models into one federated model. Interference Check is run to find clash points between disciplines, and every valid clash is re-coordinated until all system routes fit and can be executed. This process is covered in more depth in our article on clash detection in Revit for HVAC.
5. Producing Sheets, Sections, and Details
Once the model is clash-free, shop drawing sheets are produced from it: plan views per floor, sections at congested points such as shafts and corridors, and connection and hanger details for ducting and piping. Because they are taken directly from the model, every size and elevation on the sheets is consistent with the coordinated condition.
6. Extracting Schedules and the BOQ
Revit allows schedules for ducting, piping, and equipment to be taken directly from the model, including the bill of quantity (BOQ) for material procurement. Because this data comes from the same model as the shop drawing, the quantities and specifications on the BOQ match what will actually be installed.
7. Review and Approval
Before being issued for installation, the shop drawing is reviewed together with the project owner, MEP consultant, or main contractor to confirm every coordination note has been addressed. Revisions at this stage are far cheaper than revisions after material has already been installed on site.
8. As-Built Updates
After installation is complete, the model and shop drawing are updated into as-built drawings that reflect the actual installed condition, including any small changes made during work on site. These as-built drawings become the reference for future maintenance and repairs.
What Clients Should Prepare
For this workflow to run smoothly, clients should prepare an already-approved HVAC design drawing, the latest architectural and structural drawings or model, capacity and specification information for the units to be installed, and a project schedule showing when shop drawings need to be ready before procurement and installation begin.
Deliverables Clients Receive
From this process, clients receive a coordinated HVAC Revit model, a complete set of shop drawings with sheets, sections, and details, material schedules and the BOQ, and as-built drawings once installation is complete. All of these documents stay consistent with each other because they come from the same model.
When to Contact an HVAC Consultant
Contact an HVAC consultant or contractor experienced in producing model-based shop drawings if your project still relies on 2D design drawings without coordination against other disciplines, if procurement and installation are starting soon and need working drawings already proven clash-free, or if you need model and as-built documentation as a long-term maintenance reference. As explained in our article on HVAC design with a 3D Revit model, coordinating at the model stage is far cheaper than fixing problems once installation is already underway.
Solusi Karya Nusantara helps building owners, MEP consultants, and main contractors in Medan and the surrounding area produce HVAC shop drawings from a coordinated 3D Revit model, from the design stage through to issuing working drawings and as-builts, with 3D Revit HVAC design services for commercial and industrial buildings.