Offset on an octagon

Hi everyone, on the bottom set of windows in the attached tower model I’m trying to get a small render that surrounds the windows and offset from the main polysurface by 5. You’ll see two curves for the profile of this polysurface and a sweep that defines the join between the 2 surfaces of the polysurface I’m trying to achieve. Because this is a poly that has to be made by offsetting in 4 different directions I’m struggling to get this to work. Planarsrf is of course out and network srf doesn’t seem to be working either. I could make each srf individually and join them but I feel like there’s an easi1 2 er way round this, any help would be really appreciated

I’ve also thought about offset crv and srf but the sub crvs offset in 2 different directions. To get the outer curve ive made a small sweep and run dupedges

Hello - please post a file with the objects you are asking about.


To be honest I’ve just done this by making and joining single surfaces, but if there is a way to do this it’d be really helpful to know how for the future
Octagonal solid offset problem.3dm (2.9 MB)