The place is a small room with kitchen and toilet/shower in the basement with small windows facing local grocery store, so during the day it's dark and in the late evening you can expect some noises/chatter coming from the outside (as local stores are places for social gatherings too :) ). Main bed is a rather hard.
Taking above into account it's a good place to stay for some nights in close neighborhood to the center of Lisbon. And the host (David) is very kind and helpful.