The father-of-three died after falling from the sixth floor of a luxury apartment complex under construction in Putney.
He landed on two colleagues who were injured in the tragedy at the St James site.
Friend Andrius Raskevicius told the London Evening Standard: “He was a lovely man and very committed to his family. He was a great dad and husband
“He was a good friend as well and would help anybody out.”
Kopickas is believed to have been leaning against a metal barrier when he fell and hit two builders on the way down.
He had been in this country for more than a decade working in the construction industry.
An HSE investigation into the accident is ongoing.