Complex sentence: The building itself was unusual for Vienna: designed in the French Neo-Renaissance "hôtel particulier" style 2, the layout was U-shaped, three stories high and set back from the street by a courtyard, with the estate fenced off by a high iron grill.
Split into simpler sentences: The building itself was--unusually, for Vienna--designed in the French Neo-Renaissance "hôtel particulier" style 2. The layout was U-shaped, three stories high and set back from the street with a courtyard, and the estate fenced off with a high iron grill.