Solibri Rule  

The Space Connection rule allows you to check whether a space is connected with an outside exit or another space via, for example, a door or an opening. This can be used for natural ventilation purposes, for checking that all rooms have easy access to corridors, or, for ensuring the building serves its daily operations as smoothly as possible.
Solibri, Inc. develops and markets Quality Assurance solutions for AECO field that improve the quality of Building Information Modeling (BIM) and make the entire design process more productive. www.solibri.com/