The apartment is described as a "loft" apartment. Despite the photo on the listing, we had expected a larger open plan space on an upper floor. Apparently the term "loft" and "studio" have the same meaning in Europe, so we were surprised that the "loft" apartment was, in fact, a very small studio, with one window over the sink facing onto another wall and a very small shower/bathroom. The positive side is that the apartment is very quiet, even though it is located in the heart of the old city.
The apartment was very clean and well equipped with new linens and kitchenware. The hosts were very hospitable and easy to contact. This could be a good choice for a short term stay to tour Valencia; however, we had planned to stay for 5 weeks. We quickly realized that it would be too small for us to stay. We left after one night.
As was just our second time using AirBnB, I did not realize the importance of thoroughly researching the guest reviews, rather than relying solely on the posted description and photos. As AirBnB explained to me, they have no control over the descriptions posted by the hosts, so guest reviews are a very important step before making a booking decision. As this was a new listing, there were no prior reviews.
Though I explained that I had expected a much larger "loft-style" living area, AirBnB determined that the host's description was accurate and that there would be no refund for the full 30 days, even though the host can now re-rent the apartment.
Though I don't think this a very equitable resolution, I understand that the problem is partially because of different definitions and expectations regarding "loft" versus "studio" apartments. My other realization is that I should have been more thorough in researching the reviews. If there are no prior reviews, it would be prudent to be a bit more cautious. This was an expensive "lesson learned". I have used AirBnB since and have been very satisfied.