New fencing - when really needed

A new "first time" fence on the left.  High quality, posts are preserved before ground installation, all surfaces preservative-finished in "Natural".  Other preservative colors available.   (Restored fence on the right).  

A "New Preservative-Finished" Fence  is in contrast to a "new raw wood" fence, i.e., unprotected from UV degradation/fading and water soak/permanent damage. 

Your back yard could have four or more different  fences, that is, built at different times, design, and levels of quality.  Most will probably be restorable, but one or more may well be just too far gone.  

No need to replace all of them, just that really bad one.   FURTHER, your new fence and restored fence can look very much alike.   As alike as the image above.   Long-lasting beauty, indeed.