By default Zope 2.9 and Plone 2.5 will load the packages in <instancehome>/lib/python (as this path will be placed in the python sys.path), but it won't load automatically the configure.zcml files, the metas, overrides and so on. For this you'll need a site.zcml file, but one isn't placed by default in the etc folder.

Inside the installed Five folder you'll find a `skel` folder. Follow the instructions in the README and you'll end up with a working z3-like setup to load configuration files.