query: SELECT
    ?item ?itemLabel 
    (SAMPLE(?site_arch) as ?site_arch_ )
    (COUNT(DISTINCT ?n) as ?n_count) 
    (GROUP_CONCAT(?nLabel; separator="; ") as ?ns) 
  WHERE
  {
    ?item wdt:P31 wd:Q15661340.
    MINUS { ?item wdt:P576 [] }
    OPTIONAL { ?item wdt:P31 ?n . FILTER( ?n != wd:Q15661340) }
    OPTIONAL { ?item wdt:P31 wd:Q839954 . BIND("Y" as ?site_arch) }
    SERVICE wikibase:label { bd:serviceParam wikibase:language "fr,en" . ?item rdfs:label ?itemLabel . ?n rdfs:label ?nLabel }
  }
  GROUP BY ?item ?itemLabel