Hello,
Is there someone how know how I can get buildings listed with attributes like Area of use (BRA) and Year of construction ?
Need “Bygningsnummer” as an unique identifier for each building and “Kommunenummer” as well.
Tag ref:bygningsnr=* is mentioned, but how to query such a request to OSM ?
I apprichiate all feedback 
Best Regards Bernt
I don’t know how one can get the area of use, however this Overpass Turbo query lists the objects in Frogn that has a ref:bygningsnr key (~13,500 items). Just visit the URL and run the query. Could be a good starting point.
This wiki page explains how those buildings were imported. I am not sure, but I couldn’t see any keys that might correspond to the year of construction there. Might have been imported as part of a separate dataset, perhaps? Do you have an example building with the year of construction?
p.s. I used OSM Ireland’s Using overpass-turbo to extract data from OpenStreetMap blog post as a reference while building that query.
Hello, Thank you for information. I visited the “overpass-turbo” site and I have managed to Query some questions and got response. Thanks a lot 
Merk at en arealberegning av bygningspolygonene ikke vil gi korrekt BRA. Det skyldes at polygonet ikke er nøyaktig nok. Noen ganger viser polygoner takutstikket, andre ganger bygningskroppen. Det er også noen år siden de fleste bygningene (og ref) er oppdatert i OSM. Kartverkets API mot Matrikkelen vil gi deg bedre data.
Arealberegning skal ikke gjøres for BRA med for BYA(Bebygd areal).
Jeg har tilgang til “Bygningspunkt utvidet” levert fra kartverket, men dette datasettet er veldig mangelfullt når det gjelder Bebygd areal. Bare 6 643 bygninger av 30 774 bygninger i Nordre Follo har utfylt verdi for BYA. Hvordan kaller man API’et for å finne f. eks BYA for bygningsnummer: 148835268 ?
Har ikke brukt det selv, du får sjekke her: Kartkatalogen