Thomas Whitmarsh, from Batley, was 21 when he plunged 17ft through an opening in the roof of a shopping centre within 10 minutes of starting the job.
He suffered serious brain injuries which left him with hearing loss, impaired speech and co-ordination. He also lost sight in one eye and developed meningitis and epilepsy.
He died of a heart attack more than two years later after suffering a seizure brought on by his injuries. He was 24.
Father Robert Whitmarsh said: “We were shocked when we heard about the accident and it was hard to take in that Tom was so seriously injured, but credit to him he battled hard to try to recover.
“We were distraught when he died. It has left a massive void in the family which will take a long time to recover from and we will never see Tom fulfil his potential and develop into the fine young man we know he could become.”
Construction firm Watkin Jones & Son was last month fined £450,000 after being convicted of breaching health and safety rules.
At the trial it emerged other holes in the roof were surrounded by scaffolding and had protection underneath to prevent falls – but this had been removed from the opening Thomas fell through.
A judge described his death as a “tragic, unnecessary and entirely avoidable” waste of a life.
Mr Whitmarsh said he was relieved at the outcome of the Health and Safety Executive prosecution and hoped it would send a warning to other businesses.
“There has now been some justice for Tom’s death and hopefully it will highlight the dangers of working at height to employers and might stop someone else from being injured in the same way,” he said.
The family has thanked serious injury specialists at law firm Irwin Mitchell, who secured rehabilitation and care support to help Thomas live independently between the accident, in Bangor, Wales in May 2007 and his death in November 2009.
Ian Bailey, a workplace injury lawyer at its Leeds office, said: “In Tom’s case he was extremely vulnerable going into his first day at work in a potentially dangerous situation working at height.
“His employers let him down when he needed their support most. Tom had no prior experience of working on a roof and he was not provided with any proper protection, training or instructions before being asked to work on the site.
“Tragically, HSE statistics show that the construction industry is the worst offender when it comes to workplace fatalities. More must be done to protect workers from injury and the safety of employees needs to be the number one priority for businesses.”