Building hierarchy

You can use Building hierarchy to define a location breakdown structure in your model. Building hierarchy can have the following hierarchy structure in Tekla Structures: project > site > building > building section > building storey > space.

You can add multiple buildings, building sections, building storeys and spaces to the model by creating them directly in your model. You can import building storeys and spaces from a reference model when both the reference model and the Tekla Structures model contain one building each.

You can use the model-specific XS_USE_INTEGRATED_BUILDING_HIERARCHIES advanced option to control whether the Building hierarchy functionality is in use. By default, the advanced option is set to TRUE and Building hierarchy is in use in new models. The hierarchy structure you define is shown in the Building hierarchy side pane and in Organizer, and it is used in IFC export.

To open the Building hierarchy side pane, go to the Manage tab on the ribbon, and click Building hierarchy.

The defined building hierarchy and the object locations in the hierarchy are common for all users of the model. Building hierarchy is shared when using Tekla Model Sharing.

Note that if you want to use Organizer or user-defined attributes to define the hierarchy, set the XS_USE_INTEGRATED_BUILDING_HIERARCHIES advanced option to FALSE, save the model and reopen it to apply the change. If you had already defined a hierarchy using Building hierarchy, this hierarchy is not shown in Organizer anymore and it is not used in IFC export. Instead, IFC export uses the hierarchy defined in Organizer or with user-defined attributes. If you change the advanced option value back to TRUE, the hierarchy defined with Building hierarchy is again shown in Organizer and it is used in IFC export.

Building hierarchy elements

Building hierarchy can have the following hierarchy structure: project > site > building > building section > building storey > space. When you select a building hierarchy element, the element is always selected in both the Building hierarchy side pane and in the model, regardless of where you select it.

Project does not have a representation in the model. You can define the properties of the project in File > Project properties.
Site does not have a representation in the model. A site is a defined area of land for construction work. You can have one site in the building hierarchy, and define the properties of the site in the property pane.
Building is represented as a spatial volume in the model. The boundaries of the volume can be displayed as wireframe or shaded wireframe.

You can have multiple buildings in your model. A building can have multiple building sections and building storeys.
Building section is represented as a spatial volume in the model. Building section is a representation of a specific portion of a building. The boundaries of the volume can be displayed as wireframe or shaded wireframe.

You can add several building sections in a building.
Building storey is represented as a horizontal plane at a specified elevation within a building or a building section. Building storey is a horizontal subdivision of a building or a building section, defined by its level within the structure. The boundaries of buildings or building sections also define the boundaries for building storeys, depending on where the building storey is created.

You can add multiple building storeys in a building and a building section.

Objects are automatically assigned to building hierarchy elements based on the center point of the object geometry, with the exception of column and panel type objects, which are assigned to hierarchy elements based on the center point of their bottom edge. A building storey includes those objects that have their center point of geometry within the space between the elevation of the storey and the elevation of the next storey above.
Space is represented as a spatial volume in the model. The boundaries of the volume can be displayed as wireframe or shaded wireframe.

Spaces define bounded areas or volumes that provide for certain functions, such as rooms, halls, or corridors within a building.

A space is automatically assigned to the closest building storey below it. The created spaces are listed in the Building hierarchy side pane under the building storeys they are assigned to. If there are no building storeys, spaces are assigned either to the site, building, or building section element.

Create a building hierarchy in the model

Create a hierarchy for the spatial structure of a building. The hierarchical structure follows the IFC spatial structure: project > site > building > building section > building storey > space.

On the Manage tab on the ribbon, click Building hierarchy.

The Building hierarchy side pane opens. Project and site are automatically created when the model is created. You cannot create them yourself in the hierarchy.
In the Building hierarchy side pane, click the button.
Click the Create building command.
1. Pick the first boundary point for the building in the model.
2. Pick the second boundary point for the building.
3. Pick the next boundary point for the building.
4. Click the middle mouse button to create the building.
  
  You can now continue by creating more buildings if you have more than one building in your model.
5. To create another building, pick another point.
6. To stop creating buildings, press Esc.
When you have finished creating buildings, you can continue by creating building sections, buildings storeys, and spaces:
- If you need building sections, use the Create building section command to create building sections in the building you created.
- If there is no need for building sections in the building, you can use the Create building storey command to create building storeys in the building.
- If there is no need for building storeys, you can use the Create space command to create spaces in the building.
Click the Create building section command.
1. Pick the first boundary point for the building section in the model.
2. Pick the second boundary point for the building section.
3. Pick the next boundary point for the building section.
4. Click the middle mouse button to create the building section.
5. To create another building section, pick another point.
6. To stop creating building sections, press Esc.
Click the Create building storey command.
1. Select a building or a building section.
2. Pick a point at the building storey elevation in the model, or enter the elevation in the property pane, and then click the Insert building storey button in the property pane.
3. To create another building storey, pick another point.
4. To stop creating building storeys, press Esc.
Click the Create space command.
1. Pick the first boundary point for the space in the model.
2. Pick the second boundary point for the space.
3. Pick the next boundary point for the space.
4. Click the middle mouse button to create the space.
5. To create another space, pick another point.
6. To stop creating spaces, press Esc.

The hierarchy is shown in the Building hierarchy side pane.

Import a building hierarchy from a reference model

You can import a building hierarchy when both the reference model and the Tekla Structures model contain one building each. The building storeys and spaces of the imported reference model will replace the building storeys and spaces of the Tekla Structures building.

If the reference model from which you want to import the building storeys and spaces is already in your model, go to step 4.

To insert a reference model to your model, click File > Import > Insert reference model.
In the Add model dialog, click Browse to select the reference model from the list.
Click Add model.
On the ribbon, click Manage > Building hierarchy to open the Building hierarchy side pane.
Click the button in the upper right corner of the Building hierarchy side pane.
Click the Import from reference model command.
Select the reference model from which you want to import the hierarchy.

You can enter characters in the Reference model name box to get a list of the available reference models that contain the entered character. Alternatively, you can select the model from the Reference models side pane, or from the model. If you select from the model, ensure that the Select reference models selection switch is active.

The name of the reference model that you select is shown in the Reference model name box.
Select the lowest level that is imported from the building hierarchy, either building storey or space.
Click Import.

If the model already has a building hierarchy, Tekla Structures displays a dialog about replacing the existing hierarchy.

If you click Replace, the building storeys and spaces are replaced as follows:
- If you have selected Building storey in Lowest level to import from building hierarchy, building storeys will be replaced with the imported building storeys.
- If you have selected Space in Lowest level to import from building hierarchy, both building storeys and spaces will be replaced with the imported building storeys and spaces.
The imported building storeys and spaces are shown in the Building hierarchy side pane. To have them visible in the model, ensure that Building hierarchy is selected in the display settings. Double-click anywhere on the model background, then in the View Properties dialog, click Display... and check that Building hierarchy is selected.

If you clear the Building hierarchy checkbox in the display settings, and click Modify, the imported building storeys and spaces are still shown in the model. Use the Redraw view command to update the view.

Modify the properties of building hierarchy elements

Tekla Structures shows the properties of the selected building hierarchy element in the property pane. If you do not have the property pane open, click the button in the side pane to show the properties.

Modify the properties in the property pane as needed. When you have finished modifying, click the Modify button to apply the changes.


Property	Description
Boundary box	Use the elevation and offset properties to define the bounding volume of the building hierarchy elements. Building and Building section: The side boundaries are the boundaries that you pick in the model when creating the building or building section. Use the Top elevation and Bottom elevation properties to define the top and bottom boundaries. Building storey: The side boundaries are defined by the boundaries of buildings or building sections, depending on where the building storey is created. The top and bottom boundaries are defined by the Elevation property, from the elevation of the building storey to the elevation of the next building storey above. If you change the elevation of a building storey that has objects assigned to it, Tekla Structures displays a dialog where you need to select whether to move the building storey only, or the building storey and the objects assigned to it. Use the Bottom offset property to define a certain distance below the storey. You can assign objects that are below the elevation of a building storey to that particular building storey. For example, if you set the bottom offset to 300 mm, the objects that are 0-300 mm below the elevation of the building storey are also assigned to that building storey. Offset is the distance from the top surface of the load-bearing structure to the top surface of the finished floor. Space: The side boundaries are the boundaries that you pick in the model when creating the space. Use the Bottom offset property to define a certain distance below the space.
IFC entity	Site, building, building section, building storey, and space all have the IFC entity property. You can only modify the IFC entity of spaces. Select the IFC entity value: `IfcSpace`, the space is exported. This is the default value. `None`, the space is not exported. `Auto`, the default value is used. Select the Subtype (IFC4) value for `IfcSpace`. The default subtype is `NOTDEFINED`. Define the User-defined type (IFC4) value. To do this, set Subtype (IFC4) to `USERDEFINED`.

Assign objects to building hierarchy elements

You can manually assign objects to desired building hierarchy elements. For example, columns that span over several storeys might not be automatically assigned to the desired building storey.


To	Do this
Assign objects manually to a building hierarchy element	On the Selecting toolbar, switch on the selection switch for assemblies and cast units . Select the objects in the model. You can assign one or more objects at a time. The objects can be located outside the building hierarchy element. Right-click and select Building hierarchy > Assign selected objects to. Select the building hierarchy element to assign the objects. If you want to restore the automatic assignment of objects, select the objects again. Right-click and select Building hierarchy > Restore default assignment for selected objects.
Show, select, and hide objects assigned to building hierarchy elements	Select a building hierarchy element in the Building hierarchy side pane. Right-click and select one of the following: Show assigned objects Displays all assigned objects that are currently hidden and ensures that all assigned objects are visible. Select assigned objects Highlights and selects all assigned objects. Hide assigned objects Hides all assigned objects. Show only assigned objects Displays only the assigned objects and hides all others. To return to the original view, right-click the view and select Redraw view.

View and filter building hierarchy elements

You can control the visibility and rendering of the building hierarchy elements in the model. You can hide and delete the elements, and report space properties.

View building hierarchy elements in the model


To	Do this
Set the visibility of building hierarchy in the model	Double-click anywhere on the model background to open the View properties dialog. Click the Display... button to open the Displaydialog. Select or clear the Building hierarchy checkbox. Click Modify.
Change the rendering of building hierarchy elements	On the View tab, click Rendering. Select the rendering option that you want to use: Building hierarchy wireframe Building hierarchy shaded wireframe

Inquire and filter building hierarchy elements


To	Do this
View to which building storey an assembly is assigned to	Inquire an assembly in the model. The building hierarchy information is shown in the result.
Filter building hierarchy objects	Use the Location breakdown structure category to filter building hierarchy objects based on their location.

Report properties of spaces


To	Do this
Report space object properties for assemblies and cast units	Use the `SPACE` template attributes to report the properties.

Create views on selected building storeys

You can create model views of the building storeys that you select in the Building hierarchy side pane or in the model.

On the View tab, click New view > On selected building storeys.
Select building storeys in the Building hierarchy side pane or in the model.
In the Create views on selected building storeys dialog, define the view name, and select the view properties.
Select whether the view is created at the building storey offset.
Click Create.

The created views are listed in the View list. On the ribbon, go to the View tab and click View list.

Example: Building hierarchy in Organizer

You can use Organizer to view the building hierarchy that you have defined.

On the ribbon, click Manage > Building hierarchy to open the Building hierarchy side pane.
On the Manage tab, click Organizer.
Select Synchronize in the dialog that opens to get the building hierarchy to Organizer.

The building hierarchy is shown at the top part of the Categories section and it has a green icon .

When you make changes in the Building hierarchy side pane, you need to synchronize Organizer to get the changes to Organizer.
If needed, you can manually make changes in the building storeys, for example, move assemblies to another building storey.

Select the assembly in the model, then right-click the target building storey in Organizer, and click the Move the selected objects command. Synchronize Organizer.

You can remove the changes that you have manually made. Select the category, click and select Manage manual changes. Select the manually added objects marked with or , right-click and select Remove manual changes. Synchronize Organizer.

Note:

When you are using Building hierarchy in your model, IFC export uses the building hierarchy storeys when the Spatial hierarchy from Organizer setting is selected in the Export IFC dialog. Spaces are also exported when you select the Spaces object type in the Export IFC dialog. Note that the hierarchies created in Organizer cannot be used at the same time.

To use the hierarchies created in Organizer in the IFC export, set XS_USE_INTEGRATED_BUILDING_HIERARCHIES to FALSE.