With Konstru you can merge one model into the other one. You can merge models entirely or only merge certain properties from one model into the other. The first example would be to merge two parts of a building. In this case you simply click the "Merge" tab and specify From and To Model on the right hand side:
If both models do not share any common elements, one model will just be merged into the other one after clicking merge. Watch a video about merging here.
However sometimes you want to merge certain properties from one model into the other one. In this case Konstru can match elements by ID or geometry. Read more about element matching here.
Now first select how you want to identify elements. Default is by ID. In case your models do not share any IDs at all, uncheck ID.
If you only want to bring certain properties across, uncheck some of the properties in "Compare these differences". If you want to bring Profile sections over only, uncheck everything except Profile.