German to English Bus/Financial Real Estate Property valuation report / description of site characteristics

This term is used as a sub-headline in a German property valuation report, more precisely in the section describing the characteristics and uses of the property/site, and refers to three buildings located on the site that are designated as "Bauteil 1", "Bauteil 2" and "Bauteil 3".

Example:

"{Headline} Bauteil 1
{Descriptive text}
Das Gebäude A aus dem Baujahr XXXX ist unterkellert. Es hat 5 Obergeschosse und besitzt ein Flachdach. Erschließung über zentrale Eingangshalle im südlichen Hausbereich, Treppenhaus und Aufzug. Massive Bauweise (Sichtmauerwerk) mit gepflegter Erscheinung. Hauseingangsbereich repräsentativ."

I am asking for the MOST appropriate term (in the context of a property valuation) and have already excluded "element", "component" and "member" as this is about entire buildings. I am thinking of using "building", "structure" or "unit". The translation is targeted at English-speaking investors (with no particular information as to US, UK or other countries).

Many thanks in advance for your help!