offset loose in 3dvoronoi

Hi im sure this question has been asken already. But i couldnt find out the way.

Im making a voronoi facade and when i ofset the cells for having dome thinknes. some of this offset go in different directions so i need to compare bouth directions for obtening the inner offset.

The problem is when i use normal offset some of the lines brake so they dont work in the comparation. what makes me use offset loose that overlaps lines.

How can obtein the biggest area?

Any help would be apreciate