I work with metric system and units in millimeters. But all new geometry from Shift+A is 200mm. How can I change it?
$\begingroup$
$\endgroup$
Use the "Add Plane" window to change value from 200mm to 150mm al subsequent planes added to this file will start with 150mm. You can then File->Defaults->SetStartupFile" to use this file as your default file.