Dynamo - filter walls based on room characteristics

Good morning everyone,

I would like to ask your opinion on the feasibility of the following procedure.

In essence, in order to determine which walls in the Revit model need to be subjected to the thermal transmittance (U) check (so all those walls that delimit a heated room and face either to an unheated room or the outside), I would like to know if there is a way to identify these walls based on the rooms they delimit.

Currently, I have delegated the choice of whether or not to check the transmittance directly to the user, via a shared parameter in which to check or uncheck the need for verification.

I would like to understand if there is a possibility of automating this step as well.

In all the rooms I have indicated in the comment whether they are heated or not. Is it possible to automate the process so that Dynamo provides me with a list of walls to verify? (if they border between a heated room and an unheated room or directly the outside)

In the case study to which I attach the plan, the result should be as follows:

M01 - M02 - M03 - M04 need to be checked as they delimit a heated room to the outside;

M07 needs to be checked as it delimits a heated room from an unheated room;

M05 - M06 do not need to be checked as they delimit unheated rooms to the outside.

In your opinion, is it feasible or do I have to be satisfied with the parameter that the user has to check or uncheck (I attach the image extracted from the walls table and how the Dynamo code is currently set)?

Thank you for your attention and good day!


I would start by placing an exterior room. I have several posts outlining how to do this on the forum, so start there if you don’t already have one.

Once that is done you can query the boundaries of any room. So start by getting all rooms, and filter out any which are conditioned using a filter by bool mask method. The remaining rooms would all require thermal isolation for any wall, ceiling, or floor which bound them. The API, some out of the box nodes and a few nodes in packages (Clockwork, Archi-lab, I think Genius Loci, and others) allow querying room boundaries, so you can use the queried results to check for isolation.

Now this may return some false positives where unconditioned rooms are adjacent to other unconditioned rooms, but it is a good start!

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Hi Jacob, thank you very much for your answer!
However, if I were to check all the walls of the heated rooms, the result would be that the thermal transmittance of the walls that separate two heated rooms, such as the kitchen and the living room, also needs to be checked, I think :thinking:
Anyway, I will try to follow your advice and update you on the results. Thank you very much! Luca

My thought was to check the walls of unheated rooms rather than heated ones.

The concern I had was that this wouldn’t flag unconditioned spaces next to unconditioned spaces (say the deck from the crawl space), but thinking on that further you could get all bounding elements bordering unconditioned spaces as noted above, and remove any which were in both lists as a way to pull out the ones which show up twice.

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