A Sydney man who brutally raped and murdered his 16-year-old friend has been sentenced to 45 years in prison for what the judge called an "unspeakably violent" and disturbing crime.

A jury found 24-year-old Aymen Terkmani guilty of sexually assaulting and killing his friend Mahmoud Hrouk in August.

Terkmani had pleaded not guilty to his charges during the trial.

Mahmoud Hrouk's body was found in a vacant house at Fairfield East. ( Facebook )

NSW Supreme Court Justice Lucy McCallum said the case was complicated as the offender did not offer any explanation for his actions.

In her sentencing remarks, Justice McCallum noted the "horrific savagery" of the "gruesome" crime that had torn the victim's family apart.

Justice McCallum said she had considered a life sentence but took the offender's age into account.

'Shattered beyond recognition'

Mahmoud was last seen alive on the evening of May 16, 2015, when security cameras captured the teenager and Terkmani eating at a fast food restaurant in Villawood.

His body, covered in blood, was found in an abandoned house in the western Sydney suburb of Fairfield East the next day.

He had been beaten with a toaster and rolling pin, strangled, and sexually assaulted.

The victim was left lying in a pool of blood and the court heard Terkmani took his clothes, phone and money.

The court heard Mahmoud's brother found him "shattered beyond recognition" at the house.

Terkmani sat in court with his eyes down, wearing a black suit with his hair pulled into a ponytail.

He appeared to be fighting back tears as the judge asked him to stand and hear his sentence.

Terkmani can apply for parole after serving 33 years of his sentence.

"The offender should not be regarded as beyond redemption," Justice McCallum said.

'Devastating' impact on victim's family

Sorry, this video has expired Mahmoud Hrouk's mother speaks outside court

In her sentencing remarks, the judge painted a picture of the victim as a hardworking, warm-hearted teen who gave most of his wages as a labourer to his parents and dreamed of building his mother a mansion.

"The impact on the family of Mahmoud Hrouk has been absolutely devastating," Justice McCallum told the court.

She described how a previously "happy and close" family who played backyard cricket and footy in the park together had been changed forever and were left "bitter, dysfunctional and torn".

The judge said the victim's injuries — which were too gruesome to describe — indicated the offender had a psycho-sexual motive.

Outside the court, a big group of family and friends of Mahmoud gathered and thanked the court for the decision.

"We all believe in the laws, we are all under the law here," Mahmoud's mother Maha Dunia said.

"I'd like to thank you all and God bless you."