# Importing the lighting that is already in the BIM model.

[Read on Lightshaped](https://lightshaped.com/guides/bim-ifc-lighting-import)

By Lightshaped

Published: 2026-09-27

Updated: 2026-11-07

An architect's BIM model often already contains the lighting design: every luminaire with its type, manufacturer, article number and position. Exported as IFC, that information can become a 3D lighting twin instead of being redrawn by hand.

## How IFC describes a luminaire

IFC (Industry Foundation Classes, ISO 16739) is the open exchange format for BIM. A luminaire is an occurrence placed in the building, usually linked to a type that holds its shared properties.

| What | IFC4 | IFC2x3 |
| --- | --- | --- |
| Luminaire occurrence | IfcLightFixture (or IfcLamp) | IfcFlowTerminal |
| Luminaire type | IfcLightFixtureType | IfcLightFixtureType |
| Link from occurrence to type | IfcRelDefinesByType | IfcRelDefinesByType |
| Position | IfcLocalPlacement chain | IfcLocalPlacement chain |
| Storey | IfcRelContainedInSpatialStructure | IfcRelContainedInSpatialStructure |

Product identity lives in property sets. Pset_ManufacturerTypeInformation carries Manufacturer, ModelLabel and ArticleNumber; the light fixture and lamp property sets can carry colour temperature, luminous flux and wattage. Many authoring tools also write their own property sets with similar names.

## Exporting it well

- Export IFC4 (Reference View) where your tool supports it; IFC2x3 Coordination View also works.
- Include the lighting fixtures category and type properties in the export, not only the building fabric.
- Fill in manufacturer, model and article number on the luminaire type. The article number is what makes an exact product match possible.
- Keep the model's length unit declared (millimetres or metres). An importer should read it from the file, not guess it.
- If the tool can only export meshes, name the luminaire objects clearly in an OBJ export (for example Downlight_01 or a Lighting Fixtures group).

## Positions are design intent

A BIM model says where a luminaire was designed to go. It is not a survey of where it was installed, and it does not know DMX addresses, controller ports or wiring. Treat imported positions as a strong starting point and confirm them on site before the installation is commissioned.

## How Lightshaped imports it

- Reads IFC2x3 and IFC4, resolving units, placement chains, storeys and property sets, and tessellates the building as non-emitting reference geometry.
- Finds luminaires by IFC class, by luminaire type, or by name for proxies, and skips things that only sound like lights, such as light switches and skylights.
- Groups them by type so you review a handful of types instead of hundreds of instances.
- Maps a type to a OneEightyOne product only on an exact published article number or model name. Other brands stay labelled as the project's own luminaires.
- Keeps the result in simulation until commissioning evidence exists; physical output stays locked.

## Questions people ask

### Which IFC entity is a light fixture?

In IFC4 it is IfcLightFixture (or IfcLamp for a lamp). In IFC2x3 luminaires are usually IfcFlowTerminal elements typed by an IfcLightFixtureType.

### Can I import luminaires from a Revit model?

Yes, through an IFC export that includes the lighting fixtures category and their type properties. Revit's IFC exporter can map manufacturer and model into Pset_ManufacturerTypeInformation.

### What if my model has no lighting yet?

The building still imports as a 3D reference. You can then place products by hand or ask Lightshaped's AI to propose a design against the real geometry.

## Sources

- [buildingSMART: official IFC schema specifications](https://technical.buildingsmart.org/standards/ifc/ifc-schema-specifications/)
- [buildingSMART: IfcLightFixture entity](https://standards.buildingsmart.org/IFC/RELEASE/IFC4/ADD2_TC1/HTML/schema/ifcelectricaldomain/lexical/ifclightfixture.htm)

## Related guides

- [From lumens and beam angle to lux.](https://lightshaped.com/guides/lumens-beam-angle-to-lux)
- [How many DMX universes does a pixel installation need?](https://lightshaped.com/guides/dmx-universes-for-pixel-installations)