Graphisoft no longer provides public, unrestricted downloads for ArchiCAD 13. You must have an active license (software key or serial number) associated with your account. If you purchased your license legally, the libraries will appear as part of the full installation package (usually named ArchiCAD_13_xx_Install.dmg for Mac or .exe for Windows).
ArchiCAD 13 expects libraries in a specific location. archicad 13 libraries download
: If you are using a newer version of Archicad (e.g., AC14 or later) but need AC13 objects, you should load the Archicad 13 Migration Library from your installation folder. Graphisoft no longer provides public