I guess you meant "around an horizontal axis".
There's no direct way to do that yet, but you can circumvent this issue with this tip:
- select the object you want to rotate
- choose the 3D view > Export to OBJ format menu item, choose a file and when prompted select the option Export selection
- choose the Furniture > Import furniture menu item, select the exported file and at the second step of the Furniture[/i] import wizard, rotate the model like you want, possibly using the shift key for a degree by degree rotation. Finish the importation, et voilà!