Hello jlms
If your wanting to create a Cinema room its best to go for a dedicated room and forget about making it multi-purpose.
Having a window in the room is daft - for your Cinema viewing your going to spend lots of time and effort getting rid of the light it lets in, its going to add to the heat in the room, its going to potentially cause an imbalance in the sound in the room and potentially its going to compromise your options for positioning your loudspeakers and possibly even your screen.
If you go with a projector (which you ought to for a Cinema room) ask the architects to revisit the design and ensure they provide decent 'silent' air conditioning into the Cinema room.
Lots of good info for you and the Architects on the CEDIA web site - inc a decent book store - see
http://www.cedia.net/ and
http://www.cedia.net/resources/
Best regards
Joe