well there also is an other method to use to rotate entire buildings that's new to the CoD 2 tools... by KilLjoY
it's a new type of entitie called misc_pfrefab
here's how it works
-make a house
in a seperate .map file just leave it unrotated you might add all the
portals , models, lights and triggers to it to make it more easier
later on
-open up the map where you want the house right click in the 2D view
and select misc --> prefab this will give you a popup window in
there select the .map file that you just made containing the house
press ok and there it is your house is in the map
and now you can rotate it anyway you want without deforming it
if you want to make some changes to the house just openup the .map file
of the house change it and save it it will also change in the other map