by Martin Phelps
When dimensioning small gaps in Revit by default, the dimension is placed between the witness lines (known as extension lines in AutoCAD), as below.
These dimensions may be drag and relocated for clarity, by selecting the dimension sting then the blue circular grip below the text.
By default this creates a curved spline extension line
To change this to may be a more UK preference, select the string of dimensions, and then “Edit Type”.
From the displayed “Type Properties” dialogue box, change the “Leader Type” from “Arc” to “Line”.
Once the “Line” option has been selected, the “Shoulder Length” property becomes available. This property may be known to AutoCAD users as the “Leader Landing”
By changing the “Shoulder Length” to 2 the result below can be produced.