Build HB zone out of several boxes


I am struggling trying to define a Honeybee zone from many adjacent boxes, just as you can in OpenStudio make a zone out of several spaces… Is there any way to do that?

This is my building here:

After hundreds of freezes (!) that force me to restart Rhino and Grasshopper, I decided to make only 3 zones out of these +80 boxes. I guess this could not harm, in the end I actually need only 3 zones but it was more convenient to build the geometry like that…


Do you think it makes sense to have 1, or even 3, zones out of this?
Those are Thermal Zones and not for nothing they are. The reliability of the results can be compromised.
Think carefully what you are trying to do …
Just a friendly advice.

Thanks for your advice, I will consider to do more (initially I wanted to do 9)… but +80 is too much, isn’t it?

Also, the problem is that I can basically not work at all like that. If I manage to do with 3 zones, it will be better than nothing… I tried to reinstall Rhino, to launch it in safe mode as administrator, increased my disk swap space but it won’t help. I probably miss some RAM but can’t deal with it right now. And I read that several people had issues when reaching about 100 zones. Anyway, this is another topic. If you know how to merge several of these boxes in one HB space, please let me know :slight_smile:

Thats actually a good point. Merging several spaces (which might have different type of use) to one common thermal zone would be of help do decrease the computational effort of 20+ zones models clearly. Actually after switching from OpenStudio to honeybee, I am missing this capability. If there is an approach available, I am also happy to hear about it.


I guess that native GH booleans can do this before starting the process of defining thermal zones.
Though i repeat my first comment. If the purpose of reducing the amount of zones is just to reduce calculation time without considering the correct setting for what a thermal zone is, i believe this approach is wrong and should not be encouraged in this group.
We are here to do things right and not just do things.

@souliane @Resry

Rhino, Grasshopper, Honeybee, OpenStudio can easily handle a project with ~100 zones. we normally have projects like 300-500 zones, and sometime like 800. But not suggested to do more than 500.

For a full building energy modeling, please refer this example to manage zones.


Hello Souliane,

I am facing the same problem with a much more simpler geometry. I want to join three spaces in a single thermal zone. I think it is possible to make a solid union to join spaces then consider the lost surfaces in the union as internal thermal mass using area analysis object.

I think 3 or 9 zones is not enough for the building you presented. The usual recomendation is to merge spaces in a same thermal zone if they have the same orientation, same boundary conditions and same load definitions.