A specifier finds your product, downloads the family and drops it into a live project model. Three things can go wrong in the next ten minutes. The model slows down. The duct or pipe will not connect, or connects to the wrong system. Or the schedule shows blank fields where your model number and ratings should be. Any of the three is a reason to swap in a generic object, and a generic object carries none of your product data.
This guide to Revit family creation for manufacturers is for the BIM lead or marketing lead at an MEP equipment maker who has to commission or review Revit families. It gives the specification to write before modeling starts and the tests to run before release. The wider BIM services hub covers related model work.
Quick answer. A manufacturer family is ready when it loads light, connects correctly, schedules cleanly and exports a meaningful IFC class. Specify parameters and type catalogs first. Set connector system classification and flow direction deliberately. Model detail only where it helps. Map IFC class and properties. Then run a written QA checklist in a blank project before publishing.
Sources were checked on 31 October 2026. Several Autodesk help pages cited here are for Revit releases from 2017 to 2022, and several NBS pages are archived. Test every rule in the Revit release your customers use. Where this guide gives a practice rather than a source, it says so.
A note on naming. This guide says Revit because the Autodesk documents it cites describe Revit features. Heaven Designs describes its own service on its service page as BIM family creation. This post does not suggest an Autodesk partnership or endorsement.
Why does manufacturer BIM content matter to specifiers?
Designers want a product they can place in the model and check for fit. NBS, the UK publisher of the NBS BIM Object Standard, wrote in a July 2016 article that “A designer wants to be able to drop a BIM object into the project model.” Objects that carry product data also let the designer extract quantities and locations. In NBS’s 2016 National BIM Survey, 71% of respondents said they need manufacturers to provide BIM objects (NBS, July 2016, archived page; it does not state the sample). The figure is old and from one publisher’s survey, so treat it as direction, not a current market share.
The cost to a manufacturer is easy to reason about, though we are not quoting a measured loss rate. A specifier compares products under time pressure. A product with a heavy or broken family adds work for the designer, and a generic placeholder removes the work. Placeholder content does not name your product in the schedule. The same pressure applies on fast fit-out work, such as the projects in our guide to MEP drawings for tenant improvement.
Autodesk’s Revit 2017 Model Performance Technical Note makes the weight point directly. A larger family “can add significantly to a model’s size and computational burden” when it is multiplied across a whole project.
What should Revit family creation for manufacturers specify before modeling starts?
Write the specification from the product data sheet, not from the CAD file. The CAD file shows geometry. The data sheet shows what the customer needs to select, size and schedule.
| Specification item | Decide before modeling | Why it matters |
|---|---|---|
| Product range and types | List every size or model that ships as a type | Sets the type count and whether a type catalog is needed |
| Category and host | Which Revit category, and does it need a host | NBS asks that an object not rely on a host unless the product genuinely needs one |
| Parameter list | Name, type (text, length, number, yes or no), instance or type, units | Fixes schedule and tag fields |
| Shared parameter source | One shared parameter file for the whole range | Keeps names identical across every family |
| Connectors | Count, domain, size parameter, system classification, flow direction | Decides whether the system tools work |
| Clearances | Service and access zones to model as volumes | Lets coordination tests see maintenance space |
| 2D representation | Symbolic plan and section view | Keeps views light and drawings readable |
| IFC class and properties | Target class, predefined type, property sets | Controls the exported file |
| Target releases | The Revit releases your customers run | Decides how many versions you publish |
| Naming | File, type and parameter names | Avoids duplicates and collisions in a customer template |
This is a practice list assembled from the sources below. Its order is ours.
When should a manufacturer use a type catalog?
Use a type catalog when one family covers many sizes. Autodesk’s Create a Type Catalog help page defines a type catalog as an external text file that lists the types of a family, so a project loads only the types it needs and stays smaller. The same page recommends type catalogs for families with six or more types.
The mechanics are exact, and mistakes break loading:
- The file has the same name as the family and sits in the same folder, with a .txt extension.
- Line 1 is a comma, then each parameter declared as
Name##Type##Units, separated by commas. - Each later line is a type name, a comma, then one value per parameter in declaration order.
- Parameter names are case sensitive.
- For system parameters, the family itself must already hold a value, or the catalog value does not load correctly.
Here is an illustrative header and two rows for a hypothetical duct-mounted unit. The model names and sizes are invented for this example, and the layout follows the sample on Autodesk’s page, which uses centimeters.
,Model##other##,Width##length##centimeters,Height##length##centimeters,Duct_Diameter##length##centimeters
UX-10,UX-10,60,45,20
UX-16,UX-16,75,55,25Autodesk’s page shows OTHER for text, number and yes or no parameters, and 1 or 0 for yes or no values. Test any catalog by loading it into a clean project before it ships.
How should parameters and shared parameters be set up?
Use shared parameters for anything a customer will schedule or tag. Autodesk’s shared parameter help describes shared parameters as definitions that can be used in multiple families or projects, selected from a shared parameter file when you add a parameter to the family. You choose whether each is stored per instance or per type.
Two practical points follow from Autodesk’s page. First, the first time a shared parameter loads into a project, its definition is stored there. If you later change its group in the family and reload, the project definition is not overridden. Decide groups before the first release, not after customers have loaded it. Second, keep one shared parameter file under version control and use it for the whole range, so every family draws on the same definitions.
Put identity data such as model reference, product family and a data sheet link at type level. Put ratings and dimensions at type level as well, unless the user can legitimately change them on placement. The Heaven Designs service page states a similar rule. It lists shared parameters aligned to a client’s parameter files and naming rules. Its FAQ calls working tags and schedules a primary acceptance criterion. That is the company’s own statement of its checks, not an Autodesk claim.
The NBS BIM Object Standard ships its own shared parameter file. The NBS BIM Library page describes it as covering interoperability, COBie, IFC property sets and object categorization, with Revit family templates for generic, face-based, floor-based, line-based, wall-based, ceiling-based and roof-based objects.
How do connectors work for duct, pipe and electrical families?
Connectors are what make an equipment family part of a system rather than a shape. Get them wrong and a specifier cannot draw a system from your product. Autodesk’s 2022 Connector Properties page lists the settings by domain.
| Domain | Settings to define | Values Autodesk lists |
|---|---|---|
| Duct | System classification | Exhaust Air, Supply Air, Return Air, Global |
| Duct | Flow direction | In, Out, Bidirectional |
| Duct and pipe | Flow configuration | Calculated, Preset, System |
| Duct and pipe | Flow factor | Percentage of system flow for this connector, active only when configuration is System |
| Pipe | System classification | Hydronic Supply, Hydronic Return, Sanitary, Vent, Domestic Hot Water, Domestic Cold Water, Other, Fire Protection variants, Fitting, Global |
| Pipe | Flow direction | In, Out, Bidirectional (Bidirectional only when configuration is Calculated) |
| Electrical | System type | Data, Power Balanced, Power Unbalanced, Telephone, Security, Fire Alarm, Nurse Call, Controls, Communication |
| Electrical | Load classification and poles | HVAC, Lighting, Power, Other; 1, 2 or 3 poles |
Electrical connectors have no flow settings. They use system type, load classification and poles instead, so a panel family is specified differently from a pump family.
The direction rule surprises people. In an Autodesk University class handout by David Butts of Gannett Fleming, flow direction is set relative to the connector. A pump suction connection is In and the discharge is Out. An air terminal is In, because it receives air from the source, even though people picture air leaving it. The handout says most system errors its author encountered came from flow direction being mislabeled.
Placement rules from Autodesk’s 2017 About Connectors in Families page matter for fittings and inline items:
- The instance origin should sit at the intersection of the connectors.
- The primary connector belongs on the X-axis face.
- On rectangular connectors, the width should lie on the X and Y axes, not the height.
- Connector arrows show the direction a duct or pipe will extrude. They do not show flow.
Two cautions come from the same Autodesk material. First, the Model Performance note says not to set Flow Direction to Bidirectional unless the family sits in line with the network, such as a damper or valve. It says Bidirectional can make flow determination harder and affect regeneration performance. Second, the Butts handout says a Global connector takes its classification from its first connection and suits models that are not running airflow calculations. For a product with a fixed role, such as a supply grille or a chilled water pump, set the classification explicitly. Use Global only for a part that is truly used across systems.
If you want a second pair of hands on this stage, the BIM family creation service lists MEP connectors for systems, flow and sizing among its deliverables.
How much detail and file weight should a family carry?
Carry the detail a specifier needs to place, size, connect and clear the product, and no more. No standard we could read sets a megabyte limit, so this guide does not invent one. Set an internal budget by test, as the QA checklist below does.
Autodesk’s Revit 2017 note gives the direction. Use family components rather than in-place families for repeated content. Limit detailed, nested and parameterized families to necessities. Parametric families place a greater computational burden than static ones, and families that cut their hosts cost more on regeneration. Its example is a 2D toilet family that is 20% smaller than the 3D version. For complex building-services components, it advises model lines at sheet detail level in place of full 3D geometry.
NBS asks for the same discipline. Its geometry guidance says not to model parts that will not be seen and to include essential openings. It also asks for a graphical convention at 1:20, 1:50 and 1:100 under BS 8541-2. Its functional rule says object behavior “shall not compromise the performance of the project model”.
Where does LOD fit for manufacturer content?
LOD describes how reliable a model element is, not how heavy the file is. The BIMForum Level of Development Specification Part I, version 2025, is the usual reference. For central cooling equipment such as water chillers (element D3030.10), it lists these inclusions:
| LOD | What BIMForum 2025 lists for water chillers |
|---|---|
| 300 | Design-specified size, shape, spacing and location; approximate allowances for clearances; access and code clearance requirements modeled |
| 350 | Actual size, shape, spacing and location or connections of equipment; actual clearances; actual access and code clearance requirements modeled |
| 400 | Supplementary components added to the model for fabrication and field installation |
In our reading, a manufacturer family aims at the 350 row: true dimensions, connection points and service clearances for the product as sold. The 400 row concerns installation-specific components added by the project team. BIMForum says LOD 400 is “developed to the level of shop drawings” and that most models contain few if any LOD 400 elements. It also states that neither the LOD definitions nor the specification say who models an element. Our Revit MEP LOD 300 vs 400 guide covers why a detailed manufacturer family does not prove LOD 400 and how to write the scope. A family can carry 350-level information and still be light, because the information sits in connectors, parameters and clearance volumes rather than in fine solids.
What do IFC export and the NBS standard ask of a manufacturer?
Not every design team uses Revit. Customers who coordinate in other tools receive your product through IFC, so the mapping is part of the family, not an afterthought.
For Revit families, Autodesk’s Specify IFC Entities for Families help page describes two shared parameters, IFCExportAs and IFCExportType. Revit provides a file called IFC Shared Parameters.txt that contains them. You add them to the family, set values for each type, and on export the elements map to the specified IFC class and type.
Why bother? The buildingSMART repository for IFC 4.3 describes IfcBuildingElementProxy as a proxy for building elements without a defined semantic type, and it advises against using it to represent an arbitrary built element. A product that lands in the proxy class tells the receiving model very little. IFC 4.3.2.0 is the release the repository README identifies as ISO-approved. The same repository defines the property set Pset_ManufacturerTypeInformation for “characteristics of types (ranges) of manufactured products that may be given by the manufacturer”. Check which IFC version and property sets your target customers require, and test the exported file in a viewer.
The NBS BIM Object Standard is the best-known checklist for manufacturer objects. Treat the following as a map, not a substitute for the current document, which NBS distributes through its BIM library. The pages we read date from 2016 to 2018 (general and version 2.0, geometry, functional, metadata) and NBS marks them archived.
| NBS section | What the pages we read ask for | What to do with it |
|---|---|---|
| General | Object categorization, an IFC element type and predefined type; IFC4 schema identifies the object (v2.0, 2018) | Set IFC class and type per family type |
| Information | Property sets and values; v2.0 made IFC properties inside the object recommended, not required | Decide which property sets you carry and document them |
| Geometry | Millimetres at 1:1; no unseen parts; space within the external boundary; conventions at 1:20, 1:50, 1:100 | Build the symbolic 2D views and set units |
| Functional | No host dependence unless needed; must not compromise project model performance; clearance zones as volumes with show and hide | Model service zones as controllable volumes |
| Metadata | Letters, numbers and single spaces; 50 characters maximum; unique names; pattern Role_Source_Type_Subtype | Name files, types and parameters to one rule |
NBS is a UK body, and the standard is voluntary. A project in another market may follow a different information standard in its BIM execution plan. Ask the specifiers you serve which one they hold you to.
What should the QA checklist contain before a family is published?
Run this checklist in a blank project, using a template that matches the customer’s release. Record the result for each family and keep the log with the release. Items 1 to 11 test the family. Items 12 to 14 test the release package around it.
| # | Check | Pass condition | Basis |
|---|---|---|---|
| 1 | Load into a blank project | No warnings, correct category | Practice |
| 2 | Load the type catalog | Every type from the data sheet appears, names match, no load error | Autodesk type catalog page |
| 3 | Schedule the shared parameters | Every required field populates, none blank, group as intended | Practice, Autodesk shared parameter page for groups |
| 4 | Tag the family | Tag reads model and key ratings | Practice |
| 5 | Draw a system from each connector | Duct, pipe or circuit connects, system type is correct, flow value populates | Autodesk connector properties |
| 6 | Inspect connector settings | Classification explicit, direction In or Out as the product role requires, Bidirectional only if in-line | Autodesk performance note, AU handout |
| 7 | Inspect placement | Origin at connector intersection for fittings, primary connector on X-axis face, rectangular width orientation | Autodesk connector help |
| 8 | Switch views and detail levels | Symbolic 2D in plan and section, no heavy 3D at coarse detail | Autodesk performance note, NBS geometry |
| 9 | Show and hide clearance volumes | Service zones toggle, names consistent | NBS functional |
| 10 | Weight test | Record family file size, then place 50 instances and record project size and regeneration time; compare with a generic placeholder | Practice, no verified threshold |
| 11 | IFC export | Class and type are not a generic proxy, property sets present | Autodesk IFC page, buildingSMART repository |
| 12 | Naming | Unique file and type names within your rule, 50 characters or fewer if you follow NBS | NBS metadata |
| 13 | Release coverage | You have tested the release each customer group uses and stated it on the download page | Practice |
| 14 | Data sheet match | Dimensions, connection sizes and ratings equal the current data sheet, version noted | Practice |
Item 10 is deliberately a method rather than a number. A hot-water boiler and a diffuser should not share a weight budget, and no source we found publishes one. Compare against your own range and the generic placeholder a designer would otherwise use.
How should manufacturer families be distributed?
Publish one controlled set and point every channel at it. Three channels are common: your own website, third-party content platforms and libraries, and direct supply to a design team on request. NBS says products that meet its standard carry a BOS icon, so ask whether a platform you use checks against that standard.
Whichever channel you use, treat the download as a release:
- Show the family version, the date and the data sheet version it matches.
- State the Revit releases tested, and offer the type catalog and the IFC file beside the native file.
- Keep a change log so a designer can see why a family changed.
- Withdraw old versions from channels you control so the superseded file does not stay in circulation.
- Give a contact route for content problems, because specifiers report errors when they can.
If you plan to supply content to a design firm during a project, the same package feeds the model checks in a clash detection and coordination workflow. Correct connectors and clearance volumes are what make those tests meaningful for your product.
Who should build the family, and what should the brief contain?
Build in-house if you have a modeler who also understands connectors and IFC mapping. Buy it in if you have a large range, a deadline, or no one who has tested a family against the checklist above. Whoever builds it, the brief decides the result.
Send the builder these items:
- The data sheet and cut sheet.
- A dimensioned drawing for each type.
- Connection sizes and positions.
- The parameter list, with units and the instance or type choice.
- Your shared parameter file, if you have one.
- The IFC target and the list of releases.
- The checklist above, as the acceptance test.
The Heaven Designs service page asks for manufacturer cut sheets, dimensions, connection sizes and shared parameter or template standards. Its listed process runs from content brief and prototype family to parameter lock-in, library polish and a delivery pack with usage notes. It also says the service supports design firms and manufacturer content needs. Scope, release coverage and review path are agreed at scoping.
Ask for a prototype family on one product first. Review the geometry and connectors, run the checklist, and only then release the batch. A defect found on one family costs one fix. A defect found after a fifty-family batch costs fifty.
FAQ
Do we need to publish IFC files as well as Revit families?
Publish both if your customers are not all on one authoring tool. The IFC file carries class, type and property sets to tools that cannot open the native family. Test the export, because the class and properties depend on the mapping you set.
How many types before a type catalog is worth it?
Autodesk’s help page recommends type catalogs for families with six or more types. Below that, types stored in the family are simpler. The catalog’s benefit is that a project loads only the types it needs.
Does a detailed family count as LOD 400?
No. LOD 400 describes elements developed for fabrication, assembly and installation. A detailed manufacturer family can still lack the data or connections a project needs. Our LOD guide explains how to word that in a scope.
Must we follow the NBS BIM Object Standard outside the UK?
No. It is a voluntary standard from a UK publisher. It is useful as a checklist, and some projects name it in their requirements. Check the information requirements of the projects you want to be specified on.
Can Heaven Designs build manufacturer families?
The service page says the BIM family creation service supports design firms and manufacturer content needs. Share the data sheets, dimensions and connection details and the team confirms scope at scoping.
Send the product brief before the batch is planned
If your range needs families that load light, connect correctly and schedule cleanly, start from the checklist above. Review the BIM family creation service to see whether its listed deliverables match your content brief, then use our contact page to describe the product range and target releases. For a short definition of the modeling platform itself, the Revit MEP glossary entry is a starting point.