Harry Calam and his two friends jumped over a fence at a construction site and scaled a scaffolding tower in Daveygate, York, on June 24.
Harry and two friends he worked with, along with others from neighbouring bars, had gone out for drinks in York after finishing work on the night of June 23 last year.
An inquest heard Harry, who loved adventure according to his devastated mum, had been moving from one roof to another as the pals tried to get a "cool view".
As they left, Alfred Miller, who had worked with Harry for nine months prior to his death, went to a construction fence in the Daveygate area to urinate.
The friend climbed over the fence into the construction site and Harry followed him, while the other friend stayed in the street.
