We would absolutely not recommend to book this place as we had a terrible experience during our stay at Ola Living. As we made a reservation for the Sagrada Familia (high quality room), we were dropped in a complete different room (Casa Battló) without being warned about this. We were extremely surprised when we opened the door and the apartment was completely different to what we had booked online.
This space had less features and was a much lower quality apartment than the one you see on the pictures. Whenever we contacted the manager (Josep) about this, he told us this was because of a technical error which never occurs, but as he said 'unfortunately these mistakes happen' and since there was a double-booking he couldn't place us in the Sagrada Familia anymore. We were very disappointed about this, since we were extremely looking forward to having a nice high quality place instead of a basic apartment during our 4-day trip in Barcelona.
At first, he offered us a total refund or a free night for the Casa Battlo which would have been fine for us, but in fact Ola Living didn't. They just sent a bit of money back because of the price difference between the two spaces, but in fact never offered us that free night which we agreed on. Basically, we just paid the full amount for the basic apartment. After we made him aware of this and told him we still paid (even more) than the regular price for the lower quality-apartment (Casa Battló), he didn't want to offer us a free night anymore because he already gave us 30% to 40% discount (which was just the price difference between the rooms). After telling him again this wasn't a discount but just a price-resettlement he disappeared and didn't answer our message anymore.
Long story short: most likely their strategy is to book multiple bookings on the same apartment and drop the 'double bookings' in lower quality rooms for the regular price under the guise of a 'technical error'. They offer you a total refund, but it's super hard to find a nice other room at a different hotel/AirBnb in Barcelona when you're already there and have to get in there immediately. That's why their "offer" doesn't make sense, since they know you're not easily going to find something else and you almost have to stay with them. As said, the other offer (which was a free night) never worked out, since they didn't want to understand the facts and just ignored our complaint.
Be aware of this when you book this place or when you book another apartment at Ola Living. We will never book again with them.