Deleting wall causes error elsewhere far away

[patricks]

I'm trying to draw in existing walls on a building. For some reason, when I delete a wall on one side of the building (it's incorrect), I suddenly get an error about 2 rooms in my new addition on the opposite end of the building are now overlapping.

Now why in the world would a wall in an existing space affect rooms far away in a new addition space??

[lev.lipkin]

Hard to tell without looking at the model. Is it too large to be posted here? As a (very wild) example, if some roof is joined to the wall, deleting the wall will affect shape of the roof, walls attached to the roof and-or other roofs joined to this roof will get changes, etc.
Are rooms correct before or after the change?