Question Regarding Zombie Spawns in Sealed Areas

[fluid coral]

Hello all. I know this most likely isnt the right area to ask this, but besides showcase I didnt see anywhere else. I am walling off this section of street here for a compound, and I am wondering if leaving those windows and simply boarding them up will count as the area being "sealed" and prevent zombie spawns inside the walls? Thank you in advance.

[spark kiln]

As far as I know, it would be necessary to board them up, you should be able to use Debug mode to see which areas are properly sealed and whcih are not, in the "Zombie map'