His employer, hired to work on the building, had failed to provide any precautions to protect workers from falls, a court was told.
The incident, in June last year, left Daniel Telford with multiple injuries including a shattered vertebrae.
Mr Telford, now 23, of Long Marston, York, was in hospital for four weeks and had to use a wheelchair for three months after being discharged. He is still unable to return to work.
The Health and Safety Executive (HSE) prosecuted Mr Telford’s employer, Spruce and Hawe Ltd, and its director Michael Spruce, from Wetherby, for serious safety failings. Harrogate Magistrates were told Mr Telford was working with Mr Spruce on the roof of the property replacing roof lights when a roof sheet he was standing on gave way.
The HSE found the company and Mr Spruce as director had failed to take any steps to prevent falls through the roof.
Spruce and Hawe Ltd, of Blind Lane, Tockwith, York, was fined £12,000 after admitting breaching health and safety regulations. Michael Spruce, of Second Avenue, Wetherby, was fined £3,000 after pleading guilty to breaching regulations. Costs of £513 were also imposed.