~10 Minutes

Revit Sample

Learn how to create and update penetrations, recesses, and openings with conVoid.



~10 Minutes

Revit Sample

Learn how to convert and approve IFC Provision for Voids with conVoid.



~10 Minutes

Revit Sample

Learn how to convert IFC Provision for Voids and Doors to Penetraions and Openings with conVoid.



~45 Minutes


Lernen Sie die Interdisziplinäre 

Zusammenarbeit in der Schlitz- und Durchbruchsplanung mit Hilfe von conVoid.




#1   Download and Install    

Download and install conVoid for Autodesk Revit 2019, 2020, 2021, and 2022 as an admin.

  • The Plug-in is installed per machine under the following path \ProgramData\Autodesk\Revit\Addins\%year%

  • The Revit Families are installed under the following path \Documents\conclass\Revit Content\%year%\%language%

#2   Start and License     

Start Revit and make sure you are connected to the Internet to validate your license. You will find conVoid under the Ribbon Tab [conclass]. If you don´t have a License, conVoid will automatically start the Trial-Version.

  • The Button [Convert Void] is used to create and update openings, penetrations, and recesses (voids).

  • The Button [Manage Void] is used for the Approval- and Management-Process of the voids.

#3   Host- and Reference-Elements     

You need at least one clash between a Host-Element (e.g., a Wall) and a Reference-Element (e.g., a Duct) in your project. These can either be in your project or a linked one. Both elements can be an IFC- or Revit-Element of any category.



  • A clash between a Duct and a Wall

  • A clash between a Pipe and a Floor

  • A clash between a Provision for Void and a Beam

  • A clash between a Door and a Wall

  • A clash between a Generic Element and a Roof

  • A clash between two Elements of your choice



[Recommended for MEP-Engineers: to create penetrations and recesses]

[Recommended for Structural-Engineers: to create structural openings based on doors and windows]

Decide at the beginning in which Revit project you want to create and update your voids. If you are the only discipline that is involved in the void creation and managing process, you can either use your own Revit project to place and cut voids directly there (recommended), or you create a temporary Revit project just for the voids and link them into your main Revit project. If you work with multiple disciplines, please read the chapter [Set up multi-user project].

#1    Project Set-Up

As already mentioned, you need at least one clash between a Host-Element (e.g., a Wall) and Reference-Element (e.g., a Duct) to create a void. If you are the owner of the Reference-Elements and the Host-Elements are in an external IFC- or Revit model, e.g., in the architectural model, link the external model in your project. You can also link multiple external models, like architectural and structural models, to create voids based on both models. The same applies if you are the owner of the Host-Elements and link an external model with Reference-Elements. (e.g., link the external Architectural model, which includes doors and windows (Reference-Elements) in your Structural Model, to create structural openings. If you are Host- and Reference-Elements' owner, you can run conVoid directly in your project to create voids.


[Recommended for the Coordination-Process of Provision for Voids]

Suppose multiple disciplines are involved in the voids' creation and coordination process. In that case, it´s recommended to create a coordination Revit project, where all participants who approve the voids are working in one file. The following workflow is a recommendation, though you can define a different process with the help of conVoid.


#1   Handover

In the beginning, the Architect and Structural Engineer hand over their models (IFC or Revit) to the MEP-Engineer.

#2   Create/Update Voids     

The MEP-Engineer set up his Revit project as described in Chapter [Set up a single-user project].  Based on an interference check between Architectural-, Structural-, and MEP-Elements, conVoid creates Provision for Voids automatically.

Note: The MEP-Engineer can also use different software and plug-in than Revit and conVoid to create Provision for Voids. Using another system does not affect the process.

#3   Handover Provision for Voids

After creating the Provision for Voids, the MEP-Engineer hand over the voids to the Architect and Structural-Engineer as an IFC- or Revit-file.

#4    Approval of Provision for Voids

The BIM-Coordinator or other participant creates a new Revit Coordination Project and links all models (Architectural, Structural, MEP, Provision for Void, etc.) in this project. The project creator has to give all participants who run the approval process access to the newly created Coordination Project. One participant has to temporarily convert the Provision for Voids to Revit Elements based on the conVoid Families. After that, all participants can approve or reject the Provision for Voids of the MEP-Engineer.

#5   Handover Approval Results

After the approval process is done, the architect or another participant hands over the results to the MEP-Engineer in a BCF- or an Excel-File. The MEP-Engineers update the rejected Provision for Voids and hand over a new Version.

#6   Transfer Approved Voids

In the end, the Architect and Structural-Engineers transfer and cut the approved voids in their project with conVoid.

This workflow will continue until the end of the void creation and approval process.



You can create voids in your entire model or a specific part. conVoid uses all visible Elements in the active view to run an interference check and to place voids.

#1   Creating Voids based on 2D-View    

If you want to create voids in a specific Floor- or Ceiling Plan, open a 2D View and reduce the visible area by activating the Crop-View if necessary. conVoid will now create voids based on the visible elements in this view.

#2   Creating Voids based on a 3D-View    

If you want to create voids in your entire model or just a part of it, open a 3D View and reduce the visible section by activating the Section-Box if necessary. conVoid will now create voids based on the visible elements in this view.

Example:   In our example, we have a 3D View with an active Section-Box.



If you run conVoid for the first time, you have to create a profile. The profile is necessary for further documentation of the creation and approval process of the voids.

By clicking on the Button [Convert Void] or [Manage Void], a window appears to create your profile.

#1   Your Profile Name

Choose a profile name.

#2   Your Discipline

Select your discipline.

#3   Save Your Profile  

Click [OK], and the profile is saved. After creating your profile, you can start to create and manage voids.

#4   Change Your Profile

You can change your profile settings with the conVoid Manager (see chapter Manage and Approve Voids).



After clicking the Button [Convert Void] in the conclass Ribbon Tab, the conVoid Filter window opens.


The following steps have to be followed to create voids and update existing ones.

#1   Create a Void Filter and Load the conVoid Families

The Void-Filter is used to define the void creation process conditions based on a specific selection of Host- and Reference Elements. If you haven´t already created a Void-Filter, click on the Icon [New] and create a new one.

Note: If the conVoid Families are not loaded in your project yet, it appears a window to load them. You find the families under the following path [.../Documents/conclass/Revit Content/%year%/%language%]. If you can´t find the families download them here


#2   Define the Section

Depending on your active view, you have to define the section to create the voids by selecting a Top- and Base-Level. If necessary, this section can be minimized or maximized by setting an offset. 

Note: This field will be greyed out if a 3D-View with an active Section Box is open.

#3   Reference Project and Reference Elements Categories   

Select the project/s, which contains the Reference-Elements (Ducts/ Beams/ Pipes/ Doors/ Provision for Voids, etc.), and select the Reference-Elements categories.

#4   Host Project and Host Elements Categories

Select the project/s, which contains the Host-Elements (Walls/ Floors/ Beams, etc.), and select the category of the Host-Elements for horizontal and vertical voids. Hosts for horizontal voids are, for example, Walls and Beams. Hosts for vertical voids are, e.g., Floors and Roofs. 

#5   Clash Detection

Click the Refresh Button to start an Interference Check (Clash Detection) between the selected Reference- and Host-Categories.

Void Conditions

The field [Condition] will be enabled by the interference check. Now you have to define your condition for the void creation.

#6.1    Select the Placement Level/s of the Voids    

  • Host Level - The voids will be placed on the level/s of the Host-Element e.g., Base- and Top-Level of a Wall.

  • Building Story - The voids will be placed on the closest upper and lower Building Story Level

  • Reference Level - The voids will be placed on the level of the Reference-Element.

  • Specific Level - The voids will be placed on this selected Level.

#6.2   Select the modeling mode

  • Opening - conVoid creates voids/penetrations which will fully intersect the Host-Element.

  • Recess - conVoid creates recesses if the Reference-Element doesn't fully intersect the Host-Element.

  • Auto - conVoid automatically creates penetrations and recesses.

#6.3   Oversize the Voids

You can set a value to oversize the voids.

#6.4   Select the Void Families      

Select the rectangular and circular void family. You can duplicate or rename the conVoid Families to create new types (see chapter Revit Families)

#6.5   Parameter Filter

If you want to run the process with a specific selection of Reference-Elements, e.g., all Elements with the Parameter [System Classification] and the Value [Supply Air], select the Parameter and the Value in the Dropdown. Otherwise, use a global parameter like [Phase Created] to run the process with all Reference-Elements.

#6.6   Add Horizontal or Vertical Void Types

You can add and define more void types by clicking on [Add horizontal/vertical void type].

#7   Transfer Parameter      

You can transfer parameters from the Reference- or Host-Element to your voids. To do this click on [Parameter Transfer], select the reference parameter and the target parameter. If a void intersects with multiple Reference- or Host-Elements, conVoid will combine the parameters with a separator. If you run an update, the parameter will automatically be updated, without changing the Drawing-Status.


Add your own Void Parameters

You can add and use your own parameters for the transfer process:

  1. Add a new project parameter

  2. Choose a Parameter Name or select a shared parameter

  3. Make sure the Type of Parameter is set to [Text]

  4. Select the Category [Generic Models]

  5. Click [OK]

  6. The new parameter will now appear in the [Parameter Transfer] Drop-Down Menu

Note: You can also add new parameters directly in the conVoid Families (see chapter conVoid Revit Families)


#8   Set Limits and Criteria

To set limits and other criteria for the creation process, click on [Settings]


Set approval status of the void to default after a change

If a void is approved or rejected and a change is detected by conVoid, the void's approval status will be reset by conVoid.

Cut void with Host-Element

conVoid will do a cut between Host-Elements and the voids. This option only works with Host-Elements that are not linked in the model.

Lock void with Host-Element

A dependency between the Host- and Reference-Element is created. If you move or resize the Host-Element, the void will automatically change the location and dimension.

Include Host-Elements in demolished Phase

Elements assigned to the [Phase Demolished] will be included in the creation process.

Convert vertical/horizontal voids if Reference- and Host-Elements are parallel

conVoid usually ignores Elements that are parallel, e.g., if a horizontal Duct intersects with a Floor, no void will be created by conVoid. By activating this option, these voids will also be created.

Ignore voids smaller than

conVoid will not create voids smaller than the set value.

Circular voids become rectangular if the diameter is greater than

conVoid changes the shape of the voids from circular to rectangular if the diameter is greater than the set value.

Ignore voids with an angle greater than

conVoid will ignore all voids which have a greater angle than the set value.

Round up void dimension

conVoid will round up the void dimension to the nearest set value.

#9   Save Your Void Filter

Save your filter without starting the process, by clicking on [Save].

#10   Create and Update Your Voids    

Run the creation and updating process of the voids by clicking on [OK].



The following example shows the settings to create penetrations based on Ducts. The System Classification groups the Ducts to set different oversize values of the voids for each system. Of course, you can set up another Parameter Filter, select more Reference Categories or other settings to change the creation process's behavior. It is recommended to define the settings at the beginning of the creation process because each modification will change the voids' dimensions.



The following example shows the settings to create structural openings based on doors and windows. 



The following example shows the settings to convert IFC Provision for Voids into Revit Families. Make sure to set up the filter, that the dimensions of the IFC Provision for Voids will not change. Keep the oversize value at zero and adopt the settings shown below.



To avoid an automatic change of a void made by conVoid or avoid creating a void in a Host-Element or by a Reference-Element, the Parameter [Exclude from conVoid] can be used. The Parameter can be found in all Void-, Host- and Reference-Elements. Here is some example of how you can use the Parameter:

  • The Structural Engineer activates the Parameter [Exclude from conVoid] in a Beam to avoid that the MEP-Engineer places voids there.

  • conVoid makes a change of a void without wanting it. Use the [Exclude from conVoid] Parameter to avoid these changes.

  • conVoid is creating a void based on a Reference-Element, which should not be a Reference-Element. Use the [Exclude from conVoid] Parameter to avoid creating a void based on that Reference-Element.


After clicking the Button [Manage Void] in the conclass Ribbon Tab, the conVoid Manager window opens. Run your approval- or managing process here.



Select one or multiple voids in your project or the table and use the Status Buttons [Approved/ Recjected/ Pending]to set the Approval-Status of the void to approved, rejected, pending. If you want to reset the Approval-Status, click on [Reset].

       Approved   Sets the Void-Status to Approved

       Rejected   Sets the Void-Status to Rejected

       Pending   Sets the Void-Status to Pending

       Reset   Resets the Status


To filter voids in the schedule, you have various options you can activate.

       Add View Filter   Add a View-Filter in the active view to color the voids in your 2D-Plan or 3D-View based on the status color.

       Color Boxes   Changes the color of the status. The colors in your active view and the table will change automatically.

       Status Checkboxes   Displays the voids in the table based on their status

       Selection   Displays the current selection of voids

       Active View   Displays all voids visible in the active view

       Uncut   Displays all voids which are not cut with a Host-Element

       Search   Displays all voids based on the input of the Searchbox

       Show All   Reset all Filters

       Fields   Select the fields that appear in the schedule


       Cut/Uncut with Host   Cut void with Host-Element/s

       Interference Check   Run an interference check between the selected voids

             Clash Zone   Activate a clash zone of the void to check the distance between the voids.


       ChatBox    Logs all messages and changes of the void/s. You can write notes and share them with other participants.

       Parameter Box   Displays the value of the selected parameter

       Profile   Can be used to change your profile settings. Keep in mind that a change can affect the approval process because your                            previous profile name and disciple are still saved in the elements.

       Export   Export the results to Excel or CSV





The following criteria must be met in a project for a successful BCF workflow using the conVoid Manager.

  • The BCF's must be created with the conVoid Manager to establish a reference between opening and BCF. All BCF's created outside of conVoid cannot be used because they have no direct element reference. However, this does not apply to editing conVoid BCF's in other systems.

  • If not all project participants work with conVoid and other BCF systems are used, one person in the project should be responsible for exchanging the BCFs.

  • The project participants can work with different BCF systems to comment and approve the openings. When using external BCF systems, a BCF import and export must be supported by the system, and it must be possible to edit the BCF labels. To create the correct labels, please read the BCF Labels chapter.


Below are some BCF systems that meet these requirements. Other BCF systems can be viewed on the buildingSMART website.


#conVoid BCF

The conVoid Manager automatically creates a BCF for each opening with the following content:

  • Snapshot with a placeholder

  • Viewpoint

  • Title with opening ID


These BCF's can be completed with comments, new snapshots, and an extended title description.

#Creator of the BCF

If all project participants work with conVoid, the BCF exchange can take place directly between all project participants without further requirements. Use the BCF import and export function to make your results available to the other project participants and import their BCF's into your project.

If other BCF compatible systems are used, select a responsible person at the beginning of the project who will make the BCF's available to the other project participants and merge them again. For example, the following persons can assume this responsibility:

  • MEP Engineer, who creates openings with Revit and conVoid.

  • Architect, BIM Manager, or BIM Coordinator who transfers openings from the MEP Engineer with the help of conVoid.

#Requirements for BCF Editors

Users working with external BCF systems: make sure you only work with the assigned labels to your discipline. Do not delete or modify the labels of other disciplines

conVoid Manager users: make sure that the correct discipline is active in your profile before approving or commenting on openings



#BCF Labels

The approval of the openings is done by adding labels to the BCF. These labels may be named differently in the BCF systems - below is an example:


BIMcollab: Labels

BIM Track: Discipline


If you are working with an external BCF system, you have to add the correct labels. Copy the labels shown below and integrate them into your BCF system. In most cases, this can be done via the project settings. Only the labels of the disciplines that are also active in the project must be added.

Architectural Labels:

  • ARC Approved

  • ARC Rejected

Structural Labels:

  • STR Approved

  • STR Rejected

Mechanical Labels:

  • HVAC Approved

  • HVAC Rejected

Electrical Labels:

  • ELEC Approved

  • ELEC Rejected

Plumbing Labels:

  • PLBG Approved

  • PLBG Rejected

Coordination Labels:

  • COORD Approved

  • COORD Rejected

Fire Protection Labels:

  • FP Approved

  • FP Rejected

MEP Labels:

  • MEP Approved

  • MEP Rejected

Mechanical & Plumbing Labels:

  • HVAC & PLBG Approved

  • HVAC & PLBG Rejected

Mechanical & Electrical:

  • HVAC & ELEC Approved

  • HVAC & ELEC Rejected

Plumbing & Electrical Labels:

  • PLGB & ELEC Approved

  • PLGB & ELEC Rejected


#Approve and comment on the openings with external BCF systems


In the beginning, make sure that the required labels are integrated into the BCF system.


To approve an opening, you need to add the label of your discipline to the issues.


#Import/Merge BCF


When you merge BCF's using the import function in the conVoid Manager, a window appears where you can select from which discipline you want to import the results. Select the respective disciplines and import the results.


#Display of the statuses


You can use the conVoid Manager to display the different statuses of the disciplines in color. To do this, select the respective discipline from the drop-down menu, and the color filter will be updated automatically by conVoid.




The viewpoints of the conVoid BCF's are created according to the shared coordinates plus IFCSITE elevation. If you are not navigated to the opening when using an external system, check the IFC Export settings in Revit.




The conVoid Manager permanently saves all created BCF files. If you accidentally delete and restore an opening, all comments and information are still available in the BCF.


#1   Libary and Downloading

The Revit Families are installed under the following path \Documents\conclass\Revit Content\%year%\%language% if you can´t find the families or want to use them without conVoid, download them here.

#2   conVoid Families

There are nine Standard conVoid Families available, which can be used for Penetrations, Recesses, Door Openings, and Window Openings. You can create your own family type according to your needs by duplicating and renaming the standard types.

Important: Do not delete the Family Types marked as (Standard). Furthermore, do not delete the implemented Parameters. You can add your own Parameters, but to run conVoid, the implemented Parameters are required.

  • CC Annotation Void - Used to Tag the Voids

    • You can create your own Annotation Tag Familie by using the Shared Parameters.​ You find the Shared Parameter File under the following path \Documents\conclass\Revit Content\%year%\%language%

  • CC Horizontal Opening Circular - Used for Circular Penetrations and Openings in Walls, Beams,...

    • Type: Opening - Circular​ (Standard)

    • Type: Window Opening - Circular (Example for duplicating and renaming the type above)

  • CC Horizontal Opening Rectangle - Used for Rectangular Penetrations and Openings in Walls, Beams,...

    • Type: Opening - Rectangle​ (Standard)

    • Type: Door Opening - Rectangle (Example for duplicating and renaming the type above)

  • CC Horizontal Recess Circular - Used for Circular Recesses in Walls,...

    • Type: Recess - Circular​​ (Standard)

  • CC Horizontal Recess Rectangle - Used for Rectangular Recesses in Walls,...

    • Type: Recess - Rectangle​​ (Standard)

  • CC Vertical Opening Circular - Used for Circular Penetrations and Openings for Floors, Roofs,...

    • Type: Opening - Circular​​ (Standard)

  • CC Vertical Opening Rectangle - Used for Circular Penetrations and Openings for Floors, Roofs,...

    • Type: Opening - Rectangle​​ (Standard)

  • CC Vertical Recess Circular - Used for Circular Recesses for Floors, Foundations,...

    • Type: Recess - Circular​​ (Standard)

  • CC Vertical Recess Rectangle - Used for Circular Recesses for Floors, Foundations,...

    • Type: Recess - Rectangle​​ (Standard)

#3   Familie Parameters

Each Parameter has a ToolTip, which will appear in Revit by hovering the mouse over a parameter.

[Dimension Parameters]

Width, Depth, Height, and Diameter (set automatically)

These Parameters are set automatically by conVoid. These parameters should not be changed manually if the void were placed by conVoid. If you want to modify the dimensions of the voids, you can use the Oversize Parameters instead.​

Oversize Left, Right, Back, Front, Bottom, and Top (set automatically and manually)

If you define an Oversize Value in your Void Filter, the parameter will be set automatically. You can modify the Values at any time without causing a status change of the voids.

Total Width, Depth, Height, and Diameter (set automatically)

Theses Parameters represent the total Dimension of the Void. It´s sum of the Oversize Values and the Standard Dimension Values, e.g., 25mm [Oversize Left] + 30mm [Oversize Right] + 250mm [Width] = 305mm [Total Width]

Rotation X, Y, Z Axis (set automatically and manually)

The Parameter can be used to create a Sloped Void.

Clash Zone (set manually)

If the value is greater than zero, a clash zone will be activated to measure the distance to the neighbor elements.

[Distance Parameters]

The distance parameters can be used to display a specific distance of the void to a level in an annotation tag.

Distance between Levels

Displays the distance between the Lower and Upper Level of the Void.

Distance Bottom Void to Lower Level

Displays the Distance between the Bottom of the Void and the Lower Level.

Distance Center Void to Lower Level

Displays the distance between the Center of the Void and the Lower Level.

Distance Center Void to Upper Level

Displays the distance between the Center of the Void and the Lower Level.

Distance Top Void to Upper Level

Displays the distance between the Top of the Void and the Lower Level.

[Identity Parameters]

Discipline (set automatically)

Displays the Discipline, which created the void.

Changelog (set automatically)

Displays and stores the void changes detected by conVoids.

Drawn by (set automatically)

Displays the profile name of the creator.

Drawn Date (set automatically)

Displays the timestamp of the void creation or update.

Drawn Status (set automatically)

Displays the Drawn Status (Created, Changed, or Up to Date)

Approved, Rejected and Pending by (set automatically)

Displays the Approval-Status of the reviewers

Reference Elements (set automatically)

Displays the Element-Id´s of the Reference Elements

Host Elements (set automatically)

Displays the Element-Id´s of the Host Elements

[Global Parameters]

Exclude from conVoid (set manually)

To exclude elements from the conVoid process, activate the parameter. The Parameter will also appear in your Host-Categories. That means you can exclude Walls or other Elements, to avoid that conVoid create voids based on these Elements.

[Symbol Parameters]

Symbol Top and Bottom / Back and Front / Right and Left

Displays the Symbols of the void in a 2D View

#4   2D Symbols

There are various symbols implemented in the conVoid Families, which can be used to display the voids in a 2D View.