Removing a window and covering it up...

[oldfart]

Folks allow me to explain. My 1970 S.W. has one gable end facing south..which used to be a porch. Years ago I framed the porch in, put vinyl siding on that end and made this into a 4ft.X10ft. storage room. I also added in a 3ft.X4ft. sliding window in the south-facing gable wall of the new "room." Now..years later... I am remodeling this 4X10 area into another purpose and wish to cover up the window and put paneling over the entire interior of the space. Here's my quandry. For the present (freezing outside) I can just stud the window opening flush with the interior wall and apply the new paneling..and then deal with the exterior in the spring when weather permits. No problem. BUT..the interior walls are covered with 1/2in drywall. Should I space the new studs far enough outward and apply 1/2in. drywall over the studs so that the wall is the same thickness/R-value thru-out or am I fretting about nothing? Could this area (previous window opening where there would be no drywall behind the paneling) cause me future problems if I do not do so? Warping, shrinkage etc.? Come spring I will remove the old window, apply plywood and new vinyl siding over the opening and take care of the exterior. But this area of the wall will be different in R-value from the majority of the wall. Is this a concern? Mebbe I'm worrying about nothing.... but I can correct the problem now..not so easilly in the future. Well, advise me my learned friends. Audie..puzzled and heading for Lowes on Monday...