The heritage-related information is already on OSM, and I don't believe the `historic=manor` tag is appropriate here. Quoting from the OSM wiki: “The manor tag is intended for representative buildings that are or were once the administrative center of a large agricultural estate.” The intended meaning of this tag appears to be the “country houses” that can frequently be found around the UK and also here in Belgium if they haven't been converted or demolished yet. But in any case, it doesn't appear to be intended for town houses.