This house is very cosy, has a lot of sleeping possibilities and is very conveniently located in the city centre. There is a supermarket around the corner and the kitchen is well equipped to do your own cooking (which saves some money in expensive Oslo).
It is the living apartment from the family so do expect a lot of personal stuff and few space for your own belongings.
Do not take a taxi from the airport as this is very expensive. The airport train to Nationaltheatret is the best option. It is a short walk from there to the apartment.
Marius was a very responsive host. We enjoyed our stay very much. It is ideal for a larger family when spending a couple of days in Oslo.