I am still trying to get the optimum deck, in the space I have to work with (which I am grateful is as big as it is) so I would like to throw this idea out for discussion. (some will want to just throw it out 
I am convinced an around the room design will give the most entertainment and interest in using the layout. My desire to have more than three feet in width is the driving force to find a way to accomplish that self imposed requirement. This proposal will move the south wall deck off the wall by 30 inches for an aisle and expand the deck to five feet wide.
One bad piece of news is the "10 foot expansion on that wall is only a 6 foot expansion" Have a heat pump unit that needs service access in that area. The north wall could go the extra 10 feet. 
