Unit Dimension Width
The UD width is the measurement of a unit from the outside of the left jamb to the outside of the right jamb. When determining the Unit Dimensions Width, you must consider the unit configurations and the unit construction.
Unit Dimension Height
The UD height is the measurement of a unit from the top of the head jamb to the bottom of the sill. When determining the Unit Dimensions Height, you must consider the type of sill, if a transom is used, and the swing of the unit.
The opening that the unit sits in is called the Rough Opening. Therefore the Unit Dimension and the Rough Opening are related. If you are able to determine one, you are able to determine the other.