Shahid Mohammed, 37, carried out the attack on the house in Huddersfield in 2002 with other men as part of a family dispute.
It left five of the Chishti children dead, along with their mother, uncle and grandmother.
Mohammed was found guilty of eight counts of murder after a trial at Leeds Crown Court and yesterday sentenced to life in prison with a minimum of 23 years
Mohammed Shafique, who survived the house fire but lost his mother, older sister and her five daughters, and his younger brother, said: "This was the final piece of the jigsaw for justice for our family and we feel this will now bring closure for us and we can try and move on.
"Knowing he is now behind bars we feel justice has been done and we can try and move on."
Mr Shafique, who himself suffered 30 degree burns in the blaze, said the family felt contempt to Mohammed.
"He could have made it easier for us and pleaded guilty and shown some remorse," he said.
The family were asleep in their home in Osborne Road, Birkby, when petrol was poured through the letterbox and petrol bombs were put through the window in the early hours of 12 May 2002.
Mr Shafique says the events of that night are still fresh in his mind.
He said: "It was the last day of the football season and my brother Ateeq was sitting in my bedroom watching the extended highlights and he was there until about 12.15am, not long before the fire happened.
"We were all fast asleep. They used a metal bar to break the double glazed window and that's when my mother woke up and she screamed and that woke my sister up.
"My sister came to my bed and woke me up and if it wasn't for her we would have never survived. She woke up and went down the stairs to see whether it was a gas fire or cooker that had been left on. She came back but the petrol had been poured by the letter box and she couldn't get back up the stairs.
As well as 18-year-old Ateeq, his sister Nafeesa Aziz, 35, died along with her children, Tayyaba Batool, 13, Rabina Batool, 10, Ateeqa Nawaz, five, Aneesa Zawaz, two, and Najeebah Nawaz, who was six months old.
Zaib-Un-Nisa, 54, the children’s grandmother and mother of Ms Aziz and Ateeq, died in hospital after jumping out of a window in a bid to escape the flames during the attack.
Rab-Nawaz Khan, the father of the five children that died and husband to Nafeesa Aziz, cried as he said: “I will never see again my wife and my daughters.
“I am so upset, every day I think about my wife and my daughters, I just don’t know what to say.”