The house is very well located close to very many central metro stations and areas. The neighbourhood is a little bit so so but is not unsafe, it is just in an old part of the city!
The house location is great as you can walk to Castelo de S.jorge and Sé for example to Rossio and Terreiro do paco, however be advised they don't call Lisbon the 7 hills city for nothing! You need good legs! It was great staying at the house that has everything one needs for a very pleasent and comfortable stay!