bird stuck in a building

so there a bird at my work (scotland) and since he’s wild he won’t come out and we can’t get him, we’ve been giving him food and water and he’ll sometimes come to the floor when someone is nearby but not close enough to get him. The sspca said they won’t come out for him as the ceiling is really high and the only thing we can do is call for city to come remove him but it would be in a way that he wouldn’t survive which none of us want to happen. It’s in a room in the building that leads straight to shop floor but there is no opening windows or doors in the bird room so none of us have any idea how he actually got there in the first place. Any advice?