This is not an "entire guest house". It is an ensuite room, with kitchen facilities, inside the flat of the host. Cleverly designed but very small space. One enters the building and after having climbed the stairs enters the host's flat via the main door. Having entered the landing, one can access either the guest room, to the left, or the host's flat, in front. While the guest room has its own door with a lock, it is clear that it is part of the same flat, meaning that the wall between it and the rest of the flat is very thin, which leads to serious noise issues. Although the host was lovely with us, he was very noisy until very late at night, making it very difficult for us to sleep. For instance, on Saturday evening he had friends over being very noisy until after 3am. Additionally, the duvet cover wasn't large enough for us to both fit under it (and we're rather small).
On a final negative note, there was a strong smell of sewage coming from he bathroom in he mornings (it happens in old buildings, but nothing was done to alleviate it as far as we could tell, eg no air freshener) and although the place as a whole was clean, a couple of small things were quite dirty.
Apart from these negatives, we should mention the positives. We expect the host will make improvements on the issues mentioned, so we recommend considering this option anyway. Perfect location, excellent communication with host, great check-in and check-out, host allowed us to leave our suitcases in the flat until after check-out. Good shower, good heating (easy to adjust), nice touches making for a pleasant atmosphere.