Sketch++ - SOLIDWORKS add-in which enables advanced sketch functionality
Download the latest version 0.1.0 from this link
Source code is available on GitHub
When installed the 'Sketch++' toolbar and menu are added to SOLIDWORKS.
Open 2D sketch and run the 'Create offset' command.
In the property manager page select the chain of sketch segments to offset (you might need to deselect the plane if it got selected in the selection box).
You can use the 'Select partial chain' command from the 'Sketch++' toolbar to select all connected segments between two selected segments.
Click green tick to generate offset.