The guest house is around 12 min walk from the station and even takes longer when walking with luggage. However it only takes 9 minutes from Shin Koenji to Shinjuku, and it is easy to access other stations too.
The room is a bit tight for 2 people but we managed it. Common areas are cleaned every day by the host/ staff. There are towels, hair dryers and other essentials too. The room we stayed in has an automatic lock, which is so great. However, it would be better if the host could upgrade the bunk bed in the room. It makes a lot of noises every time we move and we feel like it can collapse anytime. In addition, sound proof in the guest house is not so great.
It was a decent stay and Sangwon was really friendly and easy to communicate with.