We did not meet Maren but his neighbour Ketil came to welcome us and provide all information we needed.
The flat is really nice and cosy , just like in the pictures, with chimney that we did not need to use as it was quite warm.
Nice view over Oslo , very quiet neighbourhood, we got a good sleep.
The only but is that the shower and bedroom are small, may be too small if you have mobility issues. But if you managed the 3 floors without lift then you should be OK.

Had a great time and would definitively come back!