Health and safety officials have warned protection must be in place on building sites after a Merseyside company was prosecuted over an injured worker.
Mr Lawler suffered serious head injuries in the accident
The Health and Safety Executive issued the advice as Copelare Ltd was fined £5,000 after it admitted a regulation breach at Bootle Magistrates' Court.
Darren Lawler, of Leyland narrowly missed a spiked fence when he fell on the site in School Lane, Knowsley.
HSE inspector Wayne Crumpton said the correct precautions must be followed.
The HSE warning has directed construction companies to use edge protection if workers are on high buildings, so that accidents can be prevented.
Mr Crumpton said: "A barrier should have been constructed around the perimeter of the roof.
"The barrier should have been fastened securely to the structure so that there were no gaps between the barrier and the roof edge through which a person could fall, which is what happened in this case."
Mr Lawler from Lancashire, suffered serious head and facial injuries when he landed on piles of bricks at the bottom of the building he was working on while employed by Copelare Ltd in October 2004.
Eric Mahoney, director of Copelare Ltd, said his company had been fined a quarter of the anticipated fine amount for the offence.
He added: "I think that fact we were fined £5,000 instead of £20,000 indicates how the HSE interpreted the accident.
"But it was an accident which happened on our site, even though we had edge protection."
Following the court hearing the HSE said Copelare should have ensured a permanent management presence on site and followed its own health and safety plan to review risk assessment.