To scale elements graphically, use the Scale tool with 3 clicks: the first click determines the origin, and the next 2 clicks define the scale vectors.
Revit LT calculates a scale factor by determining the ratio of the lengths of the 2 vectors. For example, suppose you sketch a first vector that is 5 feet and a second vector that is 10 feet. This creates a scale factor of 2. As a result, the elements become twice their original size.
To learn more about scaling, see About Resizing and Scaling Elements.
To scale elements graphically
Be sure to select only supported elements, such as walls and lines. The Scale tool is unavailable if your entire selection contains just one non-supported element.
The origin is the point from which the size of the element will change. The cursor snaps to various references. Press Tab to change the snap points.
As you move the cursor, blue outlines indicate the new size of the selected elements. Move the cursor back and forth along that plane until the new size is correct.
The selected elements scale so that the ends of vector 1 now coincide with those of vector 2.