We had a cozy stay for a week at Mari and Johns place.
The house is practical and estetic furnished for everybody in a family with kids. The stairs is a bit steap, but on the pluss side the house have 3 floors, two bathrooms and enough space for all of us. The house also had a cozy outdoor area and a practical location close to the woods and the city.
We higly reccomend a stay at the house if you are a family with kids visiting Oslo!