Rescue teams found four more bodies of construction workers under the building near a vocational college in Pathum Thani province after the collapse on Monday, police Maj. Gen. Smithi Mookdasanit said.
"The area has been cleared out and there are no more bodies or workers trapped underneath," he said, adding the dead included 11 men and three women.
Smithi said there were about 30 to 40 workers in the area at the time of the collapse and more than 20 people were rescued from the site.
Pathum Thani is on the northern outskirts of Bangkok.