Collect Room Area by Parameter name


very new to Dynamo. I’m stuck and need some assistance. I’m working on a appartment building. Every appartment has it’s own unique designation (“Bouwnummer”).
I want to add up the room area’s per appartment by using “Bouwnummer” ( every room in a unique appartment has the same "Bouwnummer"value) and return that value back into a Revit schedule ( and name it Collected Area or something like that) so that I can use that collected value for other calculations in a schedule.
I have allready have some work done but I don’t know how to finish it.
I wanted to ad the file but as a newbie I’m not allowed to!. Any comments and or pointers are appreciated.

I have used "All elements of category" and “parameter.parameterbyname” to make a list of rooms with the same “Bouwnummer”. I also have all the area values of every single room. Somehow I have to combine these two but I can’t figure out how.

“Please help me Obi-Wan Kenobi. You’re my only hope”


ps. Tip from another user: I have added a WeTransfer link with the .dyn file

You can share your files via WeTransfer
Upload the link you receive if you wetransfer it to yourself.

Dank je. Heb ik net gedaan

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Room_Area_by_Department.dyn (6.1 KB)

thnx for the feedback! But it’s not what I mean. I need to add up all the room area’s with the same “Bouwnummer” into 1 single value per “Bouwnummer”.

see image. I need to add up the area’s of all “Bouwnummers” with the same number. e.g. 001

what is that mean “Bouwnummers” ?

group and sum the values.

List.GroupByKey should work here

Room_Area_by_Department (1).dyn (15.6 KB)

Bouwnummers is a parameter that I added. It is Dutch for: building number. It is used to designate an appartement or house during the build, before they get assigned a final housenumber

And I’m so new to Dynamo that I don’t know how to group and sum but I get your point.

Thnx for your patience

I’ll try that

Thnx! Now at least I have the sum of all the rooms per appartment!

most gratefull

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so I ran your script and it works. I now have all rooms belonging to a certain “Bouwnummer” added up . They are listed with random numbers. So I have no idea which summarized room area belongs to which “Bouwnummer”. Is there a way to have the Bouwnummers in the list instead off just numbers ( 0,1,2,3,4,5,etc…)?

Yes you can sort and group 1st…then make sum


Out of curiousity; why don’t you use the Schedule to make the sums?


offcourse a very legit question. I did that first. And It shows up nicely in the schedule. The problem is that I need the calculated value of all the rooms per house/ appartment because I need to do other calculations with that area. ( e.g. The number off bike parking spaces I need to have per house based on the total area per house). I usually do it manually by making an areaplan and use that area. But by using the room area’s it’s much faster and with this Dynamo script I can use it over and over again in other projects.

List.GroupByFunction or List.GroupByKey?

In this case the number of bike parking spaces is calculated per unit, not per Area.

Am i up to date?

The municipalities determine the amount off bike parking spaces ( and also offcourse car parking spaces) based on the total area per unit. Every range off unit area’s has a minimum amount of bikes needed.
E.g. < 50m2, 3 bikes, 50m2< 65m2, 3 bikes. Etc. I have made a calculated value of this in a schedule. It works perfectly with areaplans. But if you use rooms, it looks at every room individualy, instead of the total area per unit. You can display it as a total when you uncheck “Itemize every instance”, but the schedule still looks at every instance!
So you get the wrong numbers
That’s why I was looking at Dynamo. It is also a good way to start determening the GBO via Rooms instead of Area’s.

But mayby I’m missing something in Schedules.