A subcontractor hired to attach cladding to a Melbourne brick wall that collapsed and killed three people has been fined $7,500 but will pay $33,500 in legal costs.

Jonathon Clyde Westmoreland, 30, has been found guilty of performing works without a building permit after a brick wall on a Grocon-owned site collapsed in March 2013.

Teenage siblings Alexander and Bridget Jones and Frenchwoman Marie-Faith Fiawoo, 33, were killed when a 15-metre section of brick wall fell onto Swanston Street in the CBD.

In sentencing Westmoreland, Melbourne magistrate Carolene Gwynn said his offending was at the mid-to-bottom level, and in imposing the fine she was not dealing with the fact the wall collapsed.

“It’s not being suggested that he take any responsibility for what happened on March 28,” Ms Gwynn said.

She said the breach was inadvertent, rather than wilful behaviour, and Westmoreland was of otherwise good character.

“I am satisfied he did not turn his mind to the need for a building permit,” Ms Gwynn said.

“He did not deem it his responsibility.”

Prosecutor Paul Holdenson said Ms Gwynn should take into account the fact the building works were carried out for profit by a person who should have known better.

“The existence of a building permit could easily have been checked,” Mr Holdenson said.

Defence barrister Peter Haag said Westmoreland was at the margins of supervisory responsibility, and that he was acting under the instruction of others.

He said site-owners Grocon didn’t bother getting a permit.

“They know their responsibility under the act, they’ve been building in the city for decades,” Mr Haag said.

Grocon Victoria Street was fined $250,000 for its role over the fatal wall collapse.