Everything that you place in the environment, whether it is annotations, measures, 3D objects can be saved to be later restored.
Saving and restoring a save
You may save your current layout (including cut parts of your space, annotations, measures, imported objects...) using the save menu in File > Save layout as. You'll be prompted to choose a save name.
To load a save you previously did, just use File > Open layout and select your previous save.
Loading a save where a section of the space has been cut with the mesh cutting tool can take some time, as the base environment is cut again on save loading.
Removing a 3D model from the library will delete this element from all the saves.
Saves are stored in the current environment data folder alongside PreVu3D application and only take context within the environment linked to the application.