During my stay, the elevator and stairwell leading up to our apartment smelled strongly of rotten eggs the entire time we were there. The smell was so bad that half of our group left the reservation and stayed at a hotel. The host at first acknowledged the problem when I brought it up over messages only saying that "it is common for many buildings in Barcelona to smell bad" and that they would send a cleaning lady. The cleaning lady never came, and besides that it was never clear how a cleaning lady could fix the terrible odor because there was no clear source, the entire stairwell/elevator area of the building had the smell, and it was seeping into our apartment from there. After I expressed these concerns, the host stopped replying altogether for the last 2 days of my 3 night reservation. The place was nice but the entire experience there was ruined by this.