The right-hand end of the Tool bar contains the Quick Preferences. These are Vectorworks and…
Vectorworks Tip #040 – Preferences – Associate Dimensions
This is a Document Preference. It is so important. It makes the dimensions associate with the objects so that when the object moves or changes size, the dimensions update automatically. This can save you from making dimensioning errors. It has saved me so many times. If you do not activate this preference, you will have to manually check all your dimensions if you change anything.