In the above example the building is enclosed and the walls are open to the sky. Yes, the spellcaster must have LOS, otherwise he/she could not cast the spell. Lets look at a couple of examples, shall we:
Vortex-- A warp lord casts a vortex between 2 parallel walls(open to sky), but the template extends beyond the wall(s). Does it shrink to fit? Under the spell it says that it is stopped(deviation) by any solid terrain. Is the Vortex effectivly "locked" in place? Do the walls take damage?
Now imagine the same thing but, it is cast at a warband hiding in a hut which is smaller than the template. Does the hut get sucked down to the 7th level of hell?
Sandstorm-- A Priestess casts a sandstorm into a hut(enclosed), thru the door, at a warband(don't ask why this is just an example
). So in effect is the sandstorm now contained in the hut(no deviation)? What if your warband was hiding behind a wall and a sandstorm moved over them from the other side of the wall, does "dead ground" apply?
Ring of Fire-- same situation as Vortex. Does ring go thru walls?
Thats it for now, I have to get my Son.