When I had to leave my previous accommodation much earlier than the normal check-in time, I was allowed to check in earlier as my room was already available. The common areas were extremely clean during my stay and all instructions were quite clear. The place is in an old building with rather thin walls / doors so do expect to hear other guests. I was there in early February and the lack of heating left my room quite cold, especially at night. All in all, the room was a great deal though in a central location in Lisbon and ideal for my purposes.