I found it may just be benifical to import a 3DS file to TCAD from TFPLAN.
In TFPLAN I can customize all elements (Windows, Doors , Walls) by size , style, color etc. If for instance I create a new Wall and change it's 'exterior' and interior surfaces to Colors instead of materials, when imported to TCAD the colors can be accessed with Edit / Select By / Color.
Because your walls contain different colors for Exterior and Interior surfaces, you can select the color for the Ext, create a layer and assign all the exterior wall surfaces to that layer. If I made all window and door glass 'blue' in color, I can then select all the glass in the whole model by the select by color method in TCAD and assign all the glass to it's own layer.
Once all elements have been transferred to thier layers , it is just a matter of changing the layers properties to the desired TCAD materail .
Creating new elements in TFPLAN that are specific to colors for import to TCAD is not very difficult and once they have been created they are always in the TFPLAN Catalog for future use.
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