I'm setting up some new templates for my new work. In my previous job we used .dwt templates to ensure that nothing on that template gets overridden without manually going into the .dwt and saving it.

Now creating a .dwt is fine. However when I then open up the template and draw in model space and save it just automatically saved as a .dwt. Now my old templates were set up that each time you drew onto the new drawing it would automatically save as a .dwg, even though you had to open a .dwt.

Have I missed some steps to achieve this setting? Or does it not exist on Mac? 

Thanks