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Collaborative Void Planning for Revit

Collaboration between all project participants is crucial for integral planning using BIM. Void planning, in particular, requires open communication and collaboration. Version 20 provides additional tools to simplify this collaboration, including a free tool for exchanges with external participants (e.g., architects or structural engineers).

The progressive implementation of BIM-based planning processes raises the question of uniform void planning standards. Cross-platform workflows and process that can be documented and archived openly often still require a lot of manual labor because program solutions generally use a proprietary interface for exchange, failing to meet the recommendations of current BIM standards that consider the exclusive use of native formats for such purposes problematic. The recently finalized DIN SPEC 91391, which specifies the functional requirements for a joint data environment (CDE; e.g., under VDI 2552 or DIN EN ISO 19650), specifically recommends buildingSMART’s BIM Collaboration Format (BCF) as of Version 2.x.

The Version 20 of liNear Solutions for Revit takes on the challenge of offering a solution for increased openness and process orientation requirements. Special construction tools for void provisions enable a BCF-based workflow for void planning. This allows open process structures to be realized for void planning and approval across disciplines.

A clear design goal during development was that opening workflows to other platforms should not be implemented at the expense of the comfort of pure Revit users. This balancing act was made possible by adding so-called snippet expansions that include all the geometric information for the creation of actual voids to the BCF exported by liNear.


You first create your plans in the liNear solution using specially-developed construction tools. This allows you to resolve collisions, place void proposals with set intervals and to connect them, if necessary. When exporting your plans in BCF, liNear’s integrated reports and tasks area enables you to add information, such as comments, screenshots, etc., to void proposals.


Communicated to your building supervisor, the free tool liNear Void Manager, now enables direct classification of proposals and the creation of voids in architectural Revit models. This uses the information stored on BIM snippets. You therefore only need a BCF file for communication.


If, instead of a Revit building model, you have a reference for an IFC model from another author system, you may, in addition to BCF, also export the provisions as own IFC models. liNear’s export option will assist you with this by configuring the necessary settings based on IFC specifications, at the push of a button. You may also use your own settings for special requirements, e.g., exporting additional Psets, for IFC exports from Revit. The integrated parameter management allows parameters written into the provisions by the liNear software to be configured to own naming conventions.


Once the void proposal has been reviewed, it is recommended that the TGA model be coordinated with the updated BCF. During this process, you compare the statuses of void proposals based on the classification information. This process will be indicated by a color code on the layout. Based on a traffic light system, accepted proposals will turn green and rejected proposals will turn red. These categories can be displayed and removed through view controls. This allows you to benefit from completed planning after coordination with the building model. For example, information about rejected void proposals will still be useful when changes are to be made to systems. In regions that have already been rejected, approval of construction measures will continue to remain unlikely for the remainder of the project. This can save you valuable time if you try to find an alternative cable routing directly. Including accepted void proposals also allows subsequent reviews of submodels and the identification of potentially redundant voids.