I'm sorry he got out, it can be scary for you both. Do you know if he was flown at his former home? If so he will likely return there so call them. You can try coaxing him down tomorrow with seed, and a long-handled fishing net handy, or set up a box trap near the loft with seed as bait. If you can reach him tonight in the dark, he should be easy to catch that way. He'll be looking for food tomorrow so it should be easy to get him if he's still around. In a pinch you can even use a laundry basket and a broom handle with some duct tape. . . trust me, it works.