BIM - Creating storeys based on data from IFC model
|Type of article||FUNCTION AND TOOL|
|Source for translation||2022-04-06|
In order to properly start integration of IFC model(s) imported into the program with the InstalSystem 5 design environment it is necessary to create storeys (worksheets) based on storeys in the IFC files. Due to the nature of IFC projects/models in architectural programs and their complexity, storeys or slabs may not be identical with our design goals - therefore the program provides various methods of creating storeys from an imported IFC model:
- using the Create storeys from IFC file function
- using the Create storeys between selected slabs/roofs from IFC file function
- manual creation of a storey in the Storeys management window.
Full capabilities of these tools are presented in the examples of use.
Location in the program
- The icons of the Create storeys from IFC file and Create storeys between selected slabs/roofs from IFC file functions are accessible in the 2D editor window on the Main tools bar in the Underlay section for the enabled Underlay editing scope.
- Storeys management is accessible in the General data window in the Building and surroundings section.
Examples of use
Analysis of the structure of model from an IFC file
The choice of the manner of storey interpretation on the basis of the IFC model loaded into the program should be preceded by an analysis of its structure. For this purpose it is necessary to use the Project browser window for the enabled Underlay scope and review the model in respect of the number of storeys and structure of the components assigned to subsequent ifcBuildingStoreys. At this stage, it is also worth considering whether all storeys visible in the IFC model are relevant from the point of view of the thermal calculation or the system under design. For more information, see: Viewing the IFC structure using the project browser.
Storeys from an IFC file
For IFC models, in which the storey structure and the assignment of construction components follow the logic of InstalSystem 5 packages, it is recommended to use the Create storeys from IFC file function, which Automatically creates storeys based on IfcBuildingStorey objects from IFC file. As a result of the operation, for each ifcBuildingStorey one Storey component is created in the project. All storeys created using the function are displayed in the Storeys management window and their data (i.e. Storey elevation or Storey height) comes from the IFC file.
Create storeys from IFC file will work properly when:
- One IFC model was loaded into the project.
- The storeys from the IFC format have the same logic as the Storey components in InstalSystem 5, i.e. they are created one above the other and the building components are assigned to the storey accordingly.
- In the IFC file the roof is created on a separate dedicated ifcBuildingStorey.
- In the model derived from the IFC there are construction components assigned to a particular ifcBuildingStorey, but they extend beyond its scope, e.g. walls spanning multiple storeys.
Storeys between indicated slabs/roofs from IFC file
If storeys structure in IFC model is not coherent with the logic of a building in InstalSystem 5, it is necessary to create storeys by means of the Create storeys between selected slabs/roofs from IFC file.
In the first step in the Project browser window for the enabled scope of Underlay it is necessary to select horizontal structural partitions (slabs and roofs) from IFC model imported into the program and then to invoke the operation. For the worksheets corresponding to successive storeys to be created correctly, all ifcSlab/ifcRoof construction components that form upper and lower boundaries for the individual storeys must be indicated.
Create storeys between selected slabs/roofs from IFC file will work properly when:
- Multiple IFC models with defined storeys have been imported into the project.
In the IFC model, storeys are defined to which only minor architectural components or other storeys not needed for the thermal model or system design have been assigned.
- In the IFC model there are storey offsets (half-storeys).
After the operation, the data of the Storey components created in the project are inherited from the IFC model:
- Storey elevation Hs - elevation of the upper edge of the ifcSlab component constituting the lower boundary of the storey
- Storey height ha - distance between top and bottom edge of ifc components delimiting a given storey
- Upper slab thickness dflo - thickness of the ifcSlab/ifcRoof component constituting the upper boundary of the storey
- Lower slab thickness dflo,l - thickness of the ifcSlab component constituting the lower boundary of the storey
- Elevation of roof top - for the last storey in the sequence, the elevation of the upper edge of the ifcSlab/ifcRoof component.
Manual creation of storeys in the Storeys management window based on an IFC model
If the above-mentioned operations do not produce Storey components correctly, the solution is to create storeys manually in the Storeys management window.
For more information, see: Creating storeys.
Hint: When creating storeys, alternative software can be used to retrieve the storey constituents, e.g. with the free tool BIMVision.
Loading multiple IFC models into a project
If multiple IFC models need to be loaded into the project, the main/basic IFC model containing the building structure should be loaded first and the necessary Storey components should be interpreted based on this, before loading further IFC models (e.g. containing services or minor architectural features).
Limiting the IFC model view
After interpreting the storey from the IFC model before continuing with the project, it is helpful to use the function: In a 2D view, only elements from storey range, which is available in the Data table window for the IFC model selected in the Project browser window. When the function is enabled, only the IFC components within the elevation range of the storeys are presented in the worksheet.
Modifying storeys created based on an IFC model
The data of the Storey components interpreted from the IFC model can be edited. After creating a storey, go to the Storeys management window, verify and, if necessary, change the data for each Storey.
Due to the nature and complexity of IFC projects/models created in architectural programs, storeys or slabs may not be the same as our intended design goals. For instance, when in an IFC model the ifcSlab components delimiting the storey range consist of several component layers, select one ifcSlab layer (e.g. the top one), and after launching the operation: Create storeys between selected slabs/roofs from IFC file, go to the Storeys management window and change the value in Upper slab thickness/Lower slab thickness to the sum of the thicknesses of all layers of the ifcSlab components.
Repeated use of the storey-creating functions
While working with a project it is possible to run again the functions that create storeys based on the imported IFC model:
- Create storeys from IFC file - each re-call of the operation will overwrite the storeys displayed in the Storeys management window with storeys created from the IFC model loaded into the project.
- Create storeys between selected slabs/roofs from IFC file - each time the operation is executed again, a dialog box opens with the question: :
- Selecting Yes causes the storeys displayed in the Storeys management window to be overwritten with storeys interpreted on the basis of the IFC model loaded into the project.
- Selecting No creates another Series of storeys component without affecting the arrangement of existing series in the project.