Thursday, December 15, 2011

Revit - Rooms vs. Spaces

The more I use Revit, the more I want to leverage the information in it. Lately, that has been in the form of calculations for my firm. Today, room area calcs. The architect set up the rooms to calculate the room area from the face of wall. We need a little bigger number electrically to maximize light per square foot, so we want to run these calcs form the center of wall instead. This is easy to change for rooms by changing a setting in the Area and Room Computations dialog.

No matter what we did, we could not get the spaces to also jump out to the wall center as well. A quick look in the Help file exposed the reason why, andwe also picked up a few facts worth knowing and passing along.

So straight out of the Help file, here are things to consider about how Revit Architecture and Revit MEP Share Information when you link a Revit Architecture project to a Revit MEP project.
  • Spaces (created in Revit MEP) can be bounded by elements in linked models, in the host model, or in both.
  • Spaces are affected by room separation lines. Rooms are not affected by space separation lines.
  • Spaces are measured from the wall finish face.
  • In Revit MEP, spaces use the computation height that is defined in the architectural model. See Computation Height.
  • A space understands in which room of a linked model it resides, and it can report the identity of that room. This information is based on relative locations, not on a link to a specific room ID.
  • Multiple spaces can access the identity of a single room in a linked model.
  • Rooms can exist in design options. (See Design Options and Rooms.) Spaces cannot exist in design options.
  • If the architectural model changes, spaces are not deleted in the host MEP model. Spaces can become unenclosed, redundant, or ambiguous, as they would if the same changes were made in the host model.
  • Modification of one model does not propagate to linked models. If the architectural model and the MEP model link to each other, changes to the architectural model may not be matched by changes in the MEP model until the MEP model is opened, resaved, and reloaded.


P. Lawton said...


Do you know of any document that details ‘best practices’ for architects who are creating rooms for their building models?

We are moving quickly towards using spaces and gbXML to export room geometry for use in Trane Trace and eQuest, and we want to be able to describe to our architect clients what we’d like to see in the room models they send to us. I am aware of the GSA template standard, but I haven’t memorized it yet, and besides, less than half our projects are federal.


Anonymous said...

Note that as of Revit 2013 version, Spaces also have issues with phases. The calculations in spaces don't travel well from one phase to the next if you have spaces in the same location but in different phases.