Just turn it into an entrance point for your house, you can place a door on both sides of that pillar..
Just be careful because if you do place doors there, people can shoot through the gaps (so make sure you have another door after that point)
I would avoid doing that because people can use the storage crate/barricade combo to climb over the doors. You could, however, use it for an exterior door to slow the people down.
I would suggest making 3 floors on the two sides of that square, then continue from there. That center pillar will stop you from building a wall THERE, but it doesn't stop you from building up the pillars around it and placing a wall ABOVE it.