In the latest version of IMPACT Project Manager you will find a Recycle Bin in the File menu.
Select the elements to restore and click OK or Apply. Now you can generate the restored elements on Plan, Elevation or 3D Drawings. In the Model Viewer click on Refresh and the restored elements will appear.
If there are question marks for length, width and height the element mark is also deleted. Then you have to make a new element mark with the same name as the deleted element before you can restore.
