Alberto and the other tenant, Felipe, are very welcoming and nice guys.
Alberto, the host, got me a new towel and bed sheets but the house itself has not heating so it can get really cold, especially at night.
As soon as I arrived, they gave me a set of keys and they explained me how to get to the closest market and metro lines: Usera, about 30 minutes to anywhere decent and Almendrales, 10 minutes to Puerta del Sol. There are also night buses from Cibeles.
The house is very quiet, as Felipe is studying and the guys travel most of the time, howeve,r the street noise may be a bit loud in the weekends.
Overall, you can feel at home for a reasonable price, meet people and talk about anything, because all of them speak English!