Elements getting mixed up converting from Brep to HB_Zones

Hi everyone!
I am pretty new to Grasshopper and honeybee, so I guess my question just comes from a lack of experience.

I am trying to import Geometry from Revit and to turn it to Honeybee Zones. To practice I am using the simple example file provided by Revit (“rac_basic_simple_project”).
I import the geometry from Revit to Rhino, using Grasshopper. To do so I do as shown in the video of rhino.inside Revit: https://www.rhino3d.com/inside/revit/beta/guides/revit-to-rhino
The geometry is greatly imported, wall are seen as walls, windows as windows etc.

Then to convert this geometry into HB_Zones, I follow the video by Chris Mackey :
2 - Honeybee Energy Modeling- HB Zones from Masses Part1: Mass2Zones

I use the Brep component to set multiple Breps, selecting all the geometry that is now in Rhino.

However, out of the HB_zones component, when I show the preview of the Walls, it shows all the model, not just the walls. And the previews for the roof, windows, etc don’t show anything.
It seems that the elements get mixed up during the conversion from geometry to HB_Zones.

Is there something that I am doing wrong? Is there a better way to convert Revit geometry into HB_Zones?

Thank you very much for your help.

Another issue is that the closed Breps are surfaces and not zones as they should be as in Chris Mackey’s video.
This way to convert Revit geometry into HB_zones might not be the right one, or I am missing some steps.

Hi @loicw

For honeybee/energyplus you will need the space/zone geometry. You can try to export the gbXML from Revit and hope the generated geometry is correct. Mostly it is not! So the best way is to rebuild the model in grasshopper/rhino using the examples you can find on the forum.

Hi @Erikbeeren,

Thank you for your answer.
gbXML is definitely not convincing, it never works great, and the bigger or more complex the projects get the less it works.

Do we know why is there so much effort put in Rhino-Grasshopper and the Revit-dynamo part is much less developed? There are so many projects done using Revit nowadays than full compatibility with the energy calculation software would make a lot of sense.

Re-drawing the entire geometry in Rhino can’t be part of an efficient workflow from a Revit model to energy analysis…

Thank you for your time!
Best !

Hi Loïc -

See these answers:

But also see this post:


1 Like

Hi @wim,

Thank you for the links.
The plugin to transfer the data between the platforms using the HBJSON format seems promising.

It’s a pity that the Dynamo development is put on hold for the moment, but they seem to actively search for diverse solutions.

Thanks again for the help.