I am looking for a good German term for a building which has only a ground floor. I found the suggestion Bungalow, but this word seems not very descriptive to me. Is eingeschossig or einstöckig a correct term for such a building?
Bungalow is sometimes used with the intended meaning, but it’s not well understood that way. For instance, a vacation home described as Bungalow used to mean a simple solitary building with just one floor, but nowadays many multi-room, single-storey apartments will also be labeled that way.
Wikipedia mentions Baracke ‘shack, shed’ – English barracks translates to Kaserne – had also a single floor, but that term cannot be used generically for such buildings, because it has a derogatory connotation.
There’s a special kind of older buildings in rural parts of Germany called Kate or Kotten. They usually have just a ground floor, but – unlike many bungalows – they have pointed roofs, so there may be living space in the attic, which may have been converted recently. Anyhow, if you want to stress the fact of a single floor this word (and its many dialectal variants) will not work reliably either.
The adjectives eingeschossig and einstöckig work perfectly well. You’d use Haus (or a compound thereof, e.g. Wohnhaus) ‘house’ or Gebäude ‘building’ with them most of the time. Like English single-stor(e)y and single-floor(ed) they are derived from relevant nouns das Geschoss and der Stock or das Stockwerk. There’s another synonym, gallicism die Etage and hence einetagig /…etaʒik/ is also possible, although it’s not yet listed at dict.cc for instance.
While Stock(werk) and Etage are numbered, e.g. in lifts, Geschoss is the preferred one for compounds: Erdgeschoss (EG) ‘ground-floor’, Untergeschoss (UG) or Kellergeschoss (KG) ‘basement’, Dachgeschoss (DG) ‘attic’ and n-th Obergeschoss (OG) ‘upper floor’. Note that sometimes “1. OG” = “2. Etage” = “2. Stock”, but elsewhere “OG” = “(Etage/Stockwerk) 1” and “EG” = “0” (cardinal, less often ordinal with dot). That means, floor numbering is ambiguous except with “OG” (and “UG”/“KG”). The mentioned Wikipedia article currently even claims that otherwise synonymous Stock and Etage correlate differently with numbering conventions: “1. Stock” = “2. Etage”.
There’s also Parterre, a French loan word for Erdgeschoss, but neither can really be used to form a compound or derive an adjective that would denote a single-storey house: *Nurparterrehaus.