The house of the singing birds is in Finikia, a quiet neighbourhood which is a short walk from the center of Oia (about 15 minutes I'd say) and has a bus stop (route: Oia to Fira and back) really close by. Communication with Irini was great. For our check-in, she met us close to the apartment, went with us to the apartment and provided us with many tips on what to do on the island of Santorini. Irini was really helpful when it came to organising trips and arranged a great boat trip for us. She even helped us get our sunglasses back after we had forgotten them on the boat!
The apartment itself is rather small. The small kitchen is equipped with some basics for cooking. However we only made our breakfast there and then ate on the sunny terrace with ocean view which was really nice. Also, the apartment is very traditional (which is great and authentic) but therefore does not provide all the luxuries that you might expect in a hotel.