Buffer selected polygon/buffer excluding area

LydiaBlake

I am wanting to draw multiple polygons of varying width and attributes around selected line features and am hoping to use the buffer functionality for this.

The polygons are to be contiguous but separate shapes within the same layer (paths and verges from a linear alignment).

I can create the first polygon easily selecting my line and using the buffer option under Modify Features, and it applies the attributes and symbology from my template correctly. 

However when I go to buffer the newly created polygon again, the original area is included in the new shape, with no options to exclude it.

I have also tried the Buffer tool in the Proximity toolbox which does give me this option, however this applies to the whole layer rather than a selection, and doesn't allow me to to construct the new polygon within the same layer. 

Any suggestions? I am a fairly basic user so simplicity is paramount!

 

LydiaBlake

I think the issue is that the buffers are still associated with the line geometry rather than being proper polygons. 

I found this query relating to ArcMap which sounds similar to what I am trying to do. https://gis.stackexchange.com/questions/8739/creating-polygon-buffer-from-line. However I already have the feature class I want to create the buffer polygons in set up.