Sydney shopkeeper Adeel Khan has been found guilty of the manslaughter of a woman and her baby who died in a fire that Khan deliberately lit in 2014.

Last week, 46-year-old Khan was found guilty of murdering Chris Noble who lived above his convenience store.

The jury found him not guilty of murdering Bianka O'Brien and her son Jude but guilty of their manslaughter.

Ms O'Brien and her baby lived in a separate neighbouring unit above the shop.

Outside court today, Mr Noble's mother Liz said it was a callous loss of three lives.

"What a dreadful waste of three young lives that should have been safe sleeping in their own beds in Rozelle as they were," she said.

"Lives taken so callously by the act of a man focused only on his own perceived needs."

Mrs Noble said she was disappointed Khan never expressed remorse or sorrow.

"That has been really, really difficult for us," she said.

John O'Brien said Khan knew his family lived in the neighbouring unit upstairs. ( AAP: Paul Miller )

Mr Noble's father, Ross, said the verdicts of manslaughter for Bianka and Jude O'Brien was not a reflection on their loss.

"It does not mean their lives are any less valuable than Chris's," Mr Noble said.

"At the end of the day no decision will be enough.

"It won't bring Chris, Bianka or Jude back."

Khan was charged over the deaths of three people who perished in the fire in 2014. ( AAP: Dan Himbrechts )

Khan was charged with three counts of murder over the deaths, but had pleaded not guilty to all three charges.

The trial heard Khan planned to destroy the shop because the business was not going well and he wanted to get out of his lease and draw on an insurance policy.

The court found the shopkeeper placed up to 10 containers of fuel around the store and laid petrol-soaked cloth trailers between them.

It was alleged Khan lit one of those trailers under the back door and the force of the massive explosion left him trapped beneath a large fridge.

Khan admitted he bought the fuel and pumped it into containers at a service station, but said it was because he wanted to test how far he could drive.

Chris Noble lived in an apartment directly above the shop.

He denied starting the shop fire and instead claimed armed robbers blindfolded and tied him up on the night of the blast and threatened to light a fire.

Crown Prosecutor Mark Tedeschi QC described this explanation as bizarre and preposterous during the trial.

The court heard Khan knew Mr Noble and two other men were living in the unit directly above his shop and that there were people living in the unit above the adjoining mobile phone store.

The husband of Ms O'Brien, John O'Brien, said Khan knew his young family lived upstairs and the shop owner would often enquire about Mr O'Brien's son.