a carport or 3 sided shed probably will double the life of an rv .
especially if you are on your third RV and plan to keep it for a decade or two a hard cover will pay off .
the expansion during the day and contraction during the night will increase the possibility of leaks at the joints and various roof openings .
a bonus is that the tires take longer to deteriorate due to ozone cracking of a parked trailer .
my 2002 komfort ( ordered new ) still looks brand new even in the 300 days of sunshine in Bend . it has been stored in a north facing shed since new .
a possibility is to start with a basic " pole building " type structure that you can add walls and a garage door as time and money permit .