Easy Offset Normal To Surface

Hello, 

I have a skin system that is composed of multiple surfaces   I have set up a diagrid structure that comes from that skin.  However the structure is on the surface and I would like to be set inside of it so that it does not show through.  I have found a couple of lengthy ways of doing this, but was curious if there was a simple way using grasshopper and maybe offsetting normal.

Thanks

Surge