Revit Tip – ‘Breaking’ overlapping Dimension Lines Trick

By Dennis Collin

I was recently asked a question whether Revit could break dimension lines in a similar way to AutoCAD. This is sometimes necessary on busy drawings where annotations overlap. This can happen with plant room, complex site drawings and coordination plans. Whilst overlapping annotations should be avoided where possible there are odd instances where it is unavoidable.

AutoCAD has a vast range of annotation and detail tools, where annotations can be customised and overridden. This can also be a weakness without suitable guidance and controls!

Revit, however, has no such obvious out-of-the-box tools, however by creating a masking region element within a generic annotation family a suitable workaround can be found. It behaves like a detail component, although a generic annotation will always be shown at the top of the draw order list whereas a similar detail item would always show behind a dimension line. Like a detail component this annotation only affects the current view, but since breaking dimension lines is a rare occurrence this concept aligns with Revit’s approach to view embellishment and detailing.

Within the generic annotation family drawing to rectangular masking regions either side of the origin. Sized approximately 2mm wide by 4mm high. Leave a gap between the regions and the family origin point of about 0.1mm. This gap will permit the crossing dimension line to be shown. Once loaded add the symbol to the relevant view and position the breaking masking region family to suit. Et voila!