David Duncan, of Parkfield Road, Oakham, was just 26 and learning his trade when he suffered spinal injuries in a fall which threatened to leave him paralysed, a top judge was told on Wednesday.
At first he was almost totally paralysed. And although he made a remarkable recovery after enduring major spinal surgery, his mobility and balance remain badly effected.
His lawyers say he will be forever handicapped on the labour market.
His barrister, David Westcott, QC, said he was working on the construction of a bungalow at Casewick Stud, Uffington, in April, 2005, when disaster struck.
In order to get into the roof space to do a measuring job, he clambered on to a trestle scaffold and pulled himself up by grasping a rafter.
But, on the way down, he bumped his head and fell first onto the trestle and then on to the concrete below.
Now Mr Duncan, who was apprenticed to his brother Neil at the time, is claiming massive damages from the main contractor on the building site, Market Deeping-based Acrabuild. He claims the firm did not do enough to protect his health and safety.
Acrabuild denies all liability in the case. The company says Mr Duncan was not employed by them and claims he was "on a frolic of his own" when he fell.
It says that it was not "reasonably forseeable" that Mr Duncan would take such an "obvious risk" by climbing into the roof void as he did.
But Mr Wescott argued Acrabuild had not done everything that was "reasonably practicable" to protect Mr Duncan, whom he described as a conscientious worker.
He claimed there was a lax atmosphere on the site and safety instructions had not been disseminated to workmen.
On Wednesday, after a three-day hearing, Deputy High Court Judge Ronald Walker QC reserved his decision in the case.
He will now give his ruling at an unspecified later date.