House Ampliation and modification - View before and after on the same model


Hi, first of all i’m from Argentina, so i’m sorry for my English:

I created an exact model of my house (how it is today).
the goal is to draw differents modifications and new rooms that i’m planing to add on the future.

I have my present model completed. So the question would be:

¿is there a way that i can create somo layer or anything else with the actual model so i can edit it and then see the differences ( for examplewith or withpout the new room) mantaining the original “untouched”?

Something like we do with te section panes and cuts (i love that) but now with differentes versions of the model. It wuold be great

Or maybe the only way is to save the present model and then make a copy and edit the new one and compare it between 2 different windows or instances of the app

Thanks in advance!


Use layers.
Leave all geometry [edges/faces] on Layer0, and assign a series of layers to groups/components made from geometry or even nested groups/components…
e.g. EXTG-WALL-0000, EXTG-WALL-0001 etc
You can then switch their visibility on/off.
Have a matching set of layers named
e.g. PROP-WALL-0000, PROP-WALL-0001 etc
If you have groups on EXTG… copy it ‘in place’ and assign the equivalent PROP… layer to that group copy.
When you edit the group it automatically becomes unique so the EXTG equivalent won’t change.
When using components editing one instance changes all others, unless you select it and choose ‘Make Unique’.
That way the EXTG and PROP equivalents are separated.

You can also then select the containers on the EXTG layers and ‘Lock’ them so they can be accidentally moved or deleted etc…

Use Scenes with different layers set on/off to see EXTG and PROP etc.

Spend a few minutes with a pencil and paper and devise the simplest layering regime to separate EXTG and PROP - of course speaking Spanish your naming will likely differ.
The naming example I gave follows the 4-character AIA conventions, set up for CAD use…
The ‘containers’ [groups or components] should also be logically constructed to reflect what needs to be kept etc…

You might also consider some other layers like DEMOlition and KEPT which can help across scenes…


I think you can accomplish what you need by careful use of components and layers.

Put the part of the model that will remain unchanged through all your modifications into one component. Put the part(s) that will be eliminated or modified into other component(s). Put each new/modified portion into its own component. Doing this will keep the various versions from interfering with each other.

Now create a layer for each portion and associate it. Then create scenes showing the appropriate layers for each state of alteration.

EditL I think that’s the same as what @TIG advised, posted while I was typing :grinning:


Not sure I am adding much to what @slbaumgartner and @TIG have already said but as this is something I do all the while, it may be useful to know how I go about it.

You have to start with a model of the house as it is. Its various components might have the word “existing” in its named layers. I would then make a copy of that and delete all the elements that would have to be demolished to allow for the new alterations. Its various components might have the word “Retained” in its named layers. Finally, you would have a set of layers for the alteration additions which might simply have the word “New” in their names. You can have them all on top of one another but select out the appropriate layers in scenes to show what you need. If you colour them differently, you can make it very obvious what is retained and what is new.


Just to be clear assume you are suggesting the use of " colour by layer", which would give an overview of the different elements of each layer (existing, retained, new etc.) as opposed to applying material/colors to those elements? Given that there will be many layers, those layer colors can be edited for clarity too while retaining existing colours and textures that may exist in the model.


Yes, good clarification. That is probably the best way for this kind of differentiation.


wow! thank you all for the quick replys!!

i had previosuly asummed that for sure layers would have to be involved.

I will try it, it seems difficult now because is new to me but is the same with everything, is a matter of test.

Now i’m at work but when i get home i’ll try and then see if its better than have 2 differents files.

Again, thank you everyone


Believe me, you really don’t want two separate files! Even in the bad old days of drawing boards, we used to have overlays. With two files, you get problems with either overlooking a conflict or of mismatch as a result of updating one and forgetting to update the other. Don’t go there is my advice!