A Sydney construction company and its director have been fined more than $500,000 after the death of a bricklayer at a building site in 2014.

The 55-year-old died when he fell five metres through a hole that had been covered with plywood but not secured to the concrete slab at a Hurstville construction site, according to a work health and safety investigation.

SafeWork NSW executive director Peter Dunphy said Romanous Contractors and its director Allen Romanous were aware of the risk but chose to ignore it.

The company was fined $425,000 and Romanous, the site manager, was fined $85,000 after a court found the work health and safety system was “ad-hoc, unplanned and inadequate”.