BIM object creation for manufacturers: from product geometry to specification data

More people open a product object than the architect who places it. The designer needs it to read correctly at 1:100 and be exact at 1:20. The specifier needs the product name, the manufacturer and a reference to write into the specification. The contractor needs exact sizes and connection points. The facility manager, years later, needs the data to still be there.

NBS splits objects into two kinds. Component objects have a fixed shape: a window, a door, a boiler. Layered objects have no fixed size: a roof membrane, a carpet, a wall build-up. In Revit those live as wall, floor and roof types rather than loadable families. Which kind your product is decides most of what follows.

Critical dimensions have to be exact: overall size, the opening a door needs, a unit's service clearance, where pipes and ducts connect. Anything a designer will never see at drawing scale comes out. Screw threads, embossed logos and gasket textures belong in the factory model, not the BIM object.

A Revit family can show different geometry at Coarse, Medium and Fine detail levels, so a 1:100 plan draws a simple outline and the 1:20 detail shows the frame. CAD or mesh geometry imported from a factory model is the most common reason a manufacturer's family is heavy, and the reason offices delete it from their libraries. Revit library optimization is what that looks like from the office's side.

Every parameter that changes the product, width, height, handing, finish, has to flex without breaking. How that gets built and tested is covered in custom parametric Revit family creation.

A schedule reads parameters, not geometry. If the fire rating sits in a text note on the object, it never reaches the door schedule. If the parameter is FR_Rating in one family and Fire Rating in the next, someone in the office fixes it by hand before both can be scheduled. What a product object carries:

• Identity: manufacturer, product name, model or product code, a link to the product page.
• Performance: the values a designer specifies against, fire rating, acoustic rating, U-value, flow or power, each in its own parameter, with its unit.
• Classification: the Revit category, and the IFC entity and property set it exports to.
• Lifecycle: expected life, maintenance interval, warranty, the fields a COBie export collects for the facility manager.

NBS's guide to object creation shows this with a roofing system classified as IfcSlabType with a ROOF subtype and Pset_SlabCommon filled in. That mapping is set once, inside the family, and decides for every project that uses it whether the product exports as a roof or as an unnamed proxy.

The NBS BIM Object Standard is the most widely used reference for manufacturer objects. It sets requirements for an object's information, geometry, behaviour and presentation in five sections: general, information, geometry, functional and metadata. It covers file, object and property naming, and the IFC and COBie properties an object carries.

If your buyers work to a different national standard, or to a large client's own BIM requirements, build to theirs. Ask two or three offices that specify your products what they check objects against. A standard nobody downstream checks is a cost, not a credential.

A manufacturer rarely has one product. It has a range: widths, finishes, handings. Model each one as its own family and the result is a folder nobody can search. One family per product line, with a type for each size, is the usual answer.

For a family with many types, a Revit type catalog is a text file that sits next to the family and lets the designer load only the types the project needs. A range that changes every year is easier to maintain in a catalog than in types saved inside the family.

Save the family in the oldest Revit version your buyers still use. Revit opens older files and upgrades them, but a family saved in a newer version won't open in an older one. For offices on Archicad or other platforms, an IFC export of the same object covers most needs, once it has been checked in an IFC viewer before publishing.

A product is discontinued. A finish changes. A test certificate is reissued with a new rating. The object on the download page still says what it said on the day it was published, and the next project specifies something the factory no longer makes.

Give every family a version number and a date in a parameter, give the library one owner, and review it whenever the price list or datasheets change. Every place the objects are published, your own site, NBS Source, BIMobject, is one more place to update, so keep the list short.

Building objects in-house works when someone on the team knows Revit families well and will still be there for the next range update. Outsourcing works when nobody does, or when the range is large and needs doing once, properly, with a template the internal team can maintain afterwards.

Either way the brief is the same: the product list, the datasheets, the standard to build to, the Revit version, and two or three offices willing to test the objects on a real project before they go public. It's the work our Revit family creation service covers.

If your buyers don't ask for BIM objects yet, or the product is specified by generic type rather than by brand, the generic family already in the design office's library does the job, and you don't need us, or anyone like us.