OBS:
In many instances of buildings on BI maps, the environment designers have placed many nearby objects to make the location more lively and interesting (such as vegetation, piles of bricks, rainwater tanks, etc).
AI's ability to move in, out and within buildings is significantly affected by these nearby objects, even if those objects do not impose on any part of the building, it's defined paths or buildingPos.
For example a bush outside the back of a house can cause AI to get stuck inside, in the parts of the building near the bush. A bush near the door of a shed can prevent AI from entering or exiting the building.

EXP:
Ideally AI should not be affected by these objects. AI should be as capable of moving within buildings as players.

Failing that, environment design should give consideration to AI when placing objects. AI testing should be performed when developing terrains.