A builder was left paralysed from the chest down when he fell through a barn roof.
Paul Blanchard broke his back and 18 ribs. He also suffered severe head injuries and a punctured lung.
Lincoln Magistrates' Court heard that Mr Blanchard was in an induced coma for three months and in hospital for another six.
The court heard he was contracted by Loates Bros Limited to replace damaged roof panels and skylights on barns at Northorpe Grange and Southorpe Farm in Blyton, near Gainsborough.
And he carried out the work at Northorpe Grange without any problems.
But, the following day – on July 18, 2010 – the 56-year-old fell more than four metres through a fragile skylight at Southorpe Farm.
A Health and Safety Executive (HSE) investigation into the incident found that Loates Bros Limited failed to assess Mr Blanchard's suitability for the job and allowed work to be carried out in an unsafe manner.
Loates Bros Limited, of Laughton near Gainsborough, pleaded guilty to two breaches of Section 3(1) of the Health and Safety at Work Act, was fined £20,000 and ordered to pay £14,995 costs.
Mr Blanchard, of Morton near Gainsborough, did not attend the court hearing on Wednesday, October 3.
"My injuries have been very hard to come to terms with, not just for me but my wife Jenny as well," he said.
"We're still having to change the way we do things, even now, more than two years on.
"My wife and two grown-up children really went through it when I was in hospital. They were told on more than one occasion that I wouldn't make it through the night.
"I feel frustrated that I can't work any more, do all the manly jobs around the house, or play squash like I used to, but I realise I'm lucky to be here. The way I see it, the glass is half full."
HSE inspector Martin Giles said: "Loates Bros Limited had a duty to ensure that contractors like Mr Blanchard were not exposed to unnecessary risks to their safety.
"One of the company directors worked with Mr Blanchard for some of the time. He noted that there was a complete lack of safety equipment in use."
Nobody was available for comment from Loates Bros Limited.