Room/Space separation lines should only be used to divide open plan spaces. They should never be run along the same line as another solid partition or used to close off an area of a model to solve an issue with the Room/Space placement tool. This results in a poorly defined gbXML with additional shading surfaces being included where they are not wanted (see images below).
Image from Autodesk Revit: Wall with room separation line running along it
Image from IES Virtual Environment: Additional shading surfaces (green) as a result of the boundary conflict.
Image from IES Virtual Environment: successful gbXML import.
Partitions Protruding into the Centre of a Room or Sit in the Middle of a Room
Where walls in a model protrude into the centre of a room or sit in the middle (walls highlighted in red below), the decision needing made is either set to ‘non-room bounding’ or to add in room separation lines to create separate spaces as indicated in the images below left(yellow dotted lines). In the example below all the walls highlighted in red had the ‘room bounding’ option unticked in their element properties. It should be noted that structural columns cause similar unwanted outcomes and should be addressed in a similar manner when building up the Revit model.
Images from Autodesk Revit: Plan view highlighting walls protruding into a room (left) and partitions in the centre of a room
Image from IES Virtual Environment: Resultant poorly defined gbXML. Unnecessary additional surfaces may cause simulation speed issues and over-complicated surface-level results (e.g. temperature).
Image from IES Virtual Environment: successful gbXML import with ‘room bounding’ option unticked.
If you plan iterative work flows (e.g. import design changes into existing VE models) or plan to export a VE loads calculation back to a gbXML file, it is crucial to use unique room names. Revit generates a new unique room ID each time a gbXML file is exported. To allow the analytical model to be easily updated from the main Revit model after each design iteration, unique room names / numbers are required to facilitate the process. This is a basic requirement of energy modelling to allow design teams to make sense of simulation results. (See examples below)
