you may want to look at vinyl fencing, much of it is recycled, and it is impervious to elements which tend to rot wood of all types (eventually). For posts, look at the Master-Halco website. They manufacture metal posts called Postmaster. Wood posts last for varying lengths of time, depending on weather, soil type and other factors. In 17 years at my current house, I replaced posts in some locations in my privacy fence 3 times before I started using 3 inch steel pipe with welded tabs. Not everyone has access to a welder so I recommend Master Halco. Look at the various vinyl fence types at ***** or **********. If you're not a diy'er call and get some estimates from a fence contractor. Good Luck