Schleich Farm World Tack Room Extension

[andrewsaurus]

Not sure if this is the place to be asking this but here goes.  The Schleich Farm World Tack Room Extension set:  the word 'extension' implies that it is to be added to some other Schleich set.  Does anyone know what set?  The Schleich Horse Barn maybe?  And if so, where does it go?  I notice the tack room set doesn't come with a roof, which i find strange.

Any help appreciated.