How come I can walk through buildings in a map I have made?

[Scott]

This is probably because you put too many A.I. / Soldiers in the map. It seems the maximum number for game stability is less than 120.

[Scott]

Posted by unknown:

there are a lot of different possibilities as to why you can walk thru a building... first, and prolly the most obvious is that the building is not placed on a flat surface (or a few feet into the surface) and you are "in effect" walking under the building...either place the building on a flat surface (use F3 to check area out), or bury the building into the terrain using an absolute-z value... i cant say that the stability of DF fails when you put in more than 120 AI...i have topped out at just over 200 AI with no stability errors...now lag is another story...