Dave Alexander shares a method for creating a new drawing from revised linework and old drawing files in AutoCAD.
"Plumbing drawings usually require multiple drawings showing plumbing systems that pass vertically through a building. The location of fixtures on one floor determines the location of the piping on the floors above and below. Small changes after the drawings are issued are easy to show, but may not require the full floor plans to be reissued. A detail sheet of the changes is usually all that is required. Good drafting practice dictates that all floor plans be drawn in model space at the same relative position so that information can be transferred between floors with the same relative reference to 0,0,0.
"Open the drawing that contains the layout tab for the revised floor plan with the revised plumbing layout. Create a new layout tab for the 8.5" x 11" detail sheet with the appropriate information shown. Once the detail sheet is correct, with viewports showing the changes as well as the correct architectural floor plan with grid bubbles, etc., open the drawing of the floor below that has the revised plumbing changes at that floor level for the changes on the floor level above. Next, right-click on the last layout tab to make a new layout and select From Template. When the dialog box appears, go to 'Files of type' and select 'Drawing *dwg.' Browse to the drawing of the floor above. From the list of layout tabs in that drawing, select the layout of the detail sheet that you just created.
"The viewport will show everything from the other detail sheet, except that the floor plan will be of this drawing with the revised piping layout. Change the appropriate title block information such as floor level, detail sheet number, etc., and you are good to go. This can also work for floor plan changes that affect more than one discipline such as HVAC, Fire Protection, etc. One detail sheet can be used as the template for them all."
Notes from Cadalyst Tip Reviewer Brian Benton: There are many different ways to achieve this, but the principle is sound. Draw everything at a scale of 1:1 in model space in the same coordinate system, whatever that may be. Manage your data (your model drawings) so that everyone can work with it and so that anyone can access it and figure out what it is. Creating a new paper space tab using the “From Template” option copies the layout tab from the specified drawing. The new tab inherits all page setups and linework (or text, dimensions, etc.) that are in that layout tab and brings them into your new tab.