I can’t move the wall. It’s not that easy because its form changes also with this method (i need a sort of offset in this case to preserve the geometry)
I have a wall (with a complex geometry) with two layers and i want to keep only one layer without modiying its position.
Please find attached a picture of an exemple (picture 1 two layers picture 2 one layer).
arhhh now i think i understand 
Can you post that model for people to test with? We’d need to see how it was modeled in the first place (pick face?) to find a specific solution.
Also I’d need to understand the ‘end goal’ you’re after once you isolate the one layer. Parts are more or less built for this - make parts and you’ve got what you’re after, just not as a wall.
Please find the above link to download the wall.
This wall is made of two layers. I want to keep the insulation of 21 mm layer (in the same position).
Thank you in advance,
What is the goal once you have just the insulation? Does it really need to be a wall? And why?
We want the insulation to be present in our model (Quantity take off, plans and visualisation). It doesn’t need to be a wall
Have you tried making parts from the wall? You can then use that to quantity take off, plans, visualization, etc. Plus it can be recreated readily when the designer changes the crazy shape (as they are apt to do).
Yes i tried making parts but the concrete wall is present (i can’t delete it and keep the insulation only) Making parts worked with only one wall.
Thank you in advance for your answear,
I am assuming you deleted the concrete part? Or are you saying you want a model with ONLY the insulation. We really need to understand the direction here. Why are you after this, what is the ‘next step’ in the process, etc.
Yes, i only want the insulation (without mooving its position). The next step is to make BOQ and plans.
Thank you 
So as your wall is ‘by face’ your options beyond parts are quite limited, as you’re limited to ‘thickening’ the base surface in Dynamo which uses a differing method.
The only option I see is to do something along these lines:
- Delete the wall
- Gather the ‘layers’ in terms of thickness and material
- Identify the index of the rigid insultation layer
- Get the material and thickness for the insulation layer
- Generate a new wall type using the thickness and insulation values
- Take the the proceeding layers from the assembly out of the list of layers
- Sum the thickness values for the layers proceeding the insulation
- Get the original massing for each of the walls
- Extend the base and top of all the wall faces significantly to account for acute normal vectors at the top/base of the wall
- Thicken the extended surfaces
- Gather the inside (the only faces which don’t touch the original faces)
- Intersect the inside face with the geometry of the original wall to ensure nothing is ‘bigger’ than the original wall
- Generate a new mass surface from that face
- Create a new wall by face on each of the inset faces using your new wall type
- Remove the insulation layer from your original wall (thereby removing overlapping geometry)
Likely the offset action is simpler to do with the original geometry - that is if it was modeled as a mass you offset the mass in the Revit UI rather than Dynamo due to the complexities of extending the top/base to account for the acute normal vectors - you’d also need to account for these at ‘ends’ if you don’t have consistent edges. Can only guess though as we haven’t seen the real project thus far.
I also recommend submitting a support ticket to the Revit team, as parts are built for this (and shockingly easy when they work) but if you’re unable to create them there is a bug that I’d like to surface to the development team.
Thank you for your answear. I have some questions. Do you mean delete the concrete wall by delete the wall ? What do you mean by gather the ‘layers’ (what is the action to do ?) ? what do you mean by 'take the proceeding layers from the assembly out of the list of layers ?
Sorry english is not my native langage
Yes - you’re going to have to host a new wall type on that mass face with just the ‘other side of the insulation’ stuff.
Get the layers of the wall type. Clockwork’s got a node called something like CompoundStructure which works well.
Gather all the layers between the host face and the insulation - I think you just have one but there will be instances where there are more than that.
So if i understand:
-1 : delete the structural wall ( the insulation changes position)
-2 : use CompoundStructure to get the insulation
Did i understand correctly the first two steps ?
Basically, yes. Note that before you delete the wall you likely want to fetch the compound structure.
Hello again, is this the compound node from clockwork’s you are refereing to ?
Yes - this will tell you what layer the insulation is at (check the materials output) and what the thickness of each layer are.
Hello,
I selected my element to get its type but void is showing for materials (please see the picture attached)
Best regards,
Do you have the correct Python dependency installed?
There are several examples of using this node on the forum as well as examples of each of the other ‘steps’ I outlined above. I suggest you start with those and get each step to work before you attempt to build a full workflow.