Man falls five metres into construction site gap and falls asleep after drunken night out

A boozy night on the town landed one man in a tight spot overnight when he fell into a crevasse between two buildings on a construction site in Brisbane's Fortitude Valley.

Construction workers found the 41-year-old man trapped between the two buildings when they arrived on the site this morning. He was fast asleep.

Queensland Fire and Emergency Services rescue crews rigged a pulley system so a firefighter and paramedic could assess the man.

Remarkably, he had no major injuries and was brought up in a harness.

The man's last memory was being out in Fortitude Valley, and authorities still aren't sure how he got into the small gap.

"He admits to being intoxicated last night, hence the no recollection," Tom Kelsey from Queensland Ambulance Service said.

"He was just concerned about his missus cause she'd be quite angry."

Technical Rescue Officer Marc O'Brien said the man most likely fell into the space as there was no other access.

"He was in reasonably good spirits considering we believe he's spent some time in that position," Mr O'Brien said.

"The space is about one metre wide, 15 metres long and the drop approximately five metres."

The man has been taken to Royal Brisbane and Women's Hospital for assessment.