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IFC Objects and IFC Geometries

During the import process, IDA ICE creates two types of elements that are available simultaneously: IFC objects and IFC geometries. Although they may appear together in the same view, they differ in how they are used during model preparation. IFC objects retain their identity from the IFC file and include elements such as spaces, walls, windows, and openings. These objects carry associated attributes and provide structured information about the building, and all of them can be reviewed in the IFC details table available in the General tab after import. IFC spaces often serve as a reference for defining zones.

The following object classes and properties are supported by the IDA ICE BIM import:

In parallel, IFC geometries are generated to represent the physical shape of elements, typically as polyhedral forms. These geometries do not carry semantic information beyond their name and shape, but they play an important role in visualization and modelling workflows. In many cases, IFC objects have corresponding geometries with matching names, although some elements such as windows and doors may not always include one. IFC geometries are not shown in floor plan views, and when present, they are used instead of IFC objects for 3D visualization. For certain elements such as slabs, walls, and roofs, geometries are always created and used to represent their shape more accurately, since the corresponding IFC objects in IDA ICE may be simplified.

Both types of elements are used together: IFC objects provide structure and meaning, while IFC geometries provide a geometric reference that can be duplicated into building bodies, zones, or other modelling elements. They can also support validation of the import process and serve as a basis for further applications such as daylight or CFD simulations. Additional IFC elements, such as beams, columns, or stairs, may also be imported as geometries when they are suitable for this purpose, with limits on geometric complexity to ensure performance.

IFC objects and IFC geometries can be managed independently, including duplication or deletion, although this should be done carefully to avoid inconsistencies in the model.

Transforming IFC Objects into IDA ICE Objects

To obtain a simulation-ready model in IDA ICE, the imported IFC objects need to be interpreted and transformed into native IDA ICE objects.

Mapping

This process begins with mapping, where information from the IFC model is associated with corresponding ICE resources. The mapping tool allows elements such as constructions, materials, window types, opening types, and spaces to be linked to definitions available in IDA ICE. In this way, the semantic meaning of the IFC data is aligned with the ICE model without modifying the underlying geometry.

The mapping window is available in the floor plan tab under the IFC menu and is organized into several sections. At the top, the user selects the category of resources to map, including:

• Constructions
• Materials
• Windows
• Openings
• Spaces

In the IFC Data section, the elements from the imported IFC file are listed as they appear in the model. The ICE Resources section displays the available resources already defined in the project. The user can inspect, load, or create resources using the available options, and then assign them by selecting an IFC element, choosing a corresponding ICE resource, and applying the mapping. This step ensures that the imported elements behave correctly in the simulation environment.

From this window, the user can inspect the resources using the View button, load resources from the IDA ICE database, or create new resources.

Spaces to thermal zones

Once the mapping is defined, the next step is to transform IFC spaces into thermal zones. As mentioned earlier, the building body is already inferred during the import process, but thermal zones must be explicitly created. In the Floor Plan tab, IFC spaces can be converted into zones linked to zone templates. Under the IFC options, three methodologies are available.

To create zones, follow these steps:

1. Select the IFC space or spaces.
2. Select the methodology.
3. Select the zone template.
4. Create the new zone.

The first option, Make a single zone from all marked IFC spaces, creates one combined thermal zone from selected spaces.

The second option, Make a separate zone from every marked IFC space, generates an individual thermal zone for each selected space.

The third option, Make a separate zone from every remaining IFC space, applies this process to all spaces that have not yet been converted.

During this transformation, IDA ICE automatically generates related elements such as windows and doors based on the associated IFC objects. This ensures that the resulting thermal zones are consistently connected to the building envelope and ready for simulation.

Working with IFC Geometries

Imported geometry can be used to define the overall form of the building when the IFC model does not directly provide usable volumes. A central operation in this process is Extrude down as building bodies. This operation takes selected geometry and projects it vertically downward to generate one or more building bodies. These building bodies represent the physical volume of the building and are used as a basis for further model definition. This approach is particularly useful when the IFC model includes well-defined upper surfaces, such as roof geometry. By selecting these surfaces and extruding them downward, the building volume can be derived in a controlled way, independent of how the original IFC elements were structured. The usefulness of imported geometry lies in its ability to support this type of operation. Even without semantic meaning, it allows the user to construct clean and consistent building bodies from available geometric references.

The transition from the imported IFC model to the working building model in IDA ICE is carried out through the operation Duplicate as. This operation defines how selected geometry or IFC objects are converted into elements that can be used in the ICE model. Depending on the selected option, geometry can be duplicated into IFC-based elements or directly into ICE elements. For example, a geometric surface can first be duplicated as an IFC window, preserving a structured intermediate representation, and this IFC element can then be further duplicated into a Face window, becoming an IDA ICE object. Alternatively, the same geometry can be duplicated directly into IDA ICE object such as Face windows, Face openings, or building bodies, without creating intermediate IFC objects. The selected path depends on the level of control required and on how the original IFC model is structured. Through this process, the imported IFC model is gradually transformed into a set of building bodies, zones, and façade elements that can be used in IDA ICE.

Visualization and editing

IDA ICE IFC objects like IFC walls, floors and roofs cannot be visualized in 3D as long as there exists IFC geometries in the model. If there are no IFC geometries existing in the model IFC walls are visualized. IFC floors and roofs cannot be visualized.

*IFC spaces **IFC windows and doors. IFC walls and roof can be visualized if no IFC geometries are available

2025-04-26

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