Be warned - Madrid can get very cold and this place has absolutely no heating, and the host will not provide a space heater (it's not uncommon for homes not to have installed heating, but hosts usually provide a space heater of some sort). I told the host that the room was cold and her response was "wrap up better" (basically meaning I should wear my coat inside).
It was too cold to stay in the apartment and so I left early, even though the host would not provide a refund. The host and her mother stayed in their room when at home, probably because it has a heater of some sort.
The room was small and dark, and there was dirt on the floor. The pillows had covers but no pillowcases, and I don't think the blankets were clean. On occasion, dishes or cups were left in the sink.
Note that your comfort is not of concern to the host, only her bills. She refused to give a refund or to provide a heater, so she got money for nothing - tells you all you need to know.