Starting the Year

As the summer draws to an end my mind always begins to wander to my classroom.  This year I am moving rooms (again) which is totally fine.  In a funny way I am actually excited about it.  It always provides the opportunity to start again.  This year the classroom I am moving to is empty.  It was our IDEA room last year so I really get the opportunity to start fresh.  The only thing I am worried about is space.  Last year the room I had was a square share.  This the the room I am moving to is a rectangle.  Technically it is only 2 square feet smaller but the shape change makes it look smaller.  I am trying to think where to place everything.  I think right now I am at 21 kids.  I am thinking desk groupings of 5 will help conserve space.  I also have a sink in one corner and a door in another as well as a door between my room and the one next door (however, I have plans to block that with a bookcase).  Past that I have the typical things to work into a classroom.  Any suggestions as to set up.