A woman whose house was set alight by a young man she had once taken in as a teenager has pleaded in court for him to leave her family alone. 

She has described the frightening moment the man called her and warned her he would be burning her house down - a chilling threat he followed through with. 

Petera Rangatiro Mihaka appeared in the Wellington District Court this morning for sentencing after earlier pleading guilty to setting the Island Bay home on fire. 

In court, the victim said her grandchildren, aged 4 and 7 at the time of the offending, were "traumatised", and so was she and her partner. 

"The boys . . . slept with the burnt weatherboards inches from their heads for months," she said. 

She recalled Mihaka calling her and warning her to get the children out of the house as he was going to burn it down. 

"We want to know that we are safe for the future . . . so today I'm asking you to think about family. 

"Leave us alone so we can live a life free of worry." 

According to Judge Bruce Davidson's sentencing indication notes, Mihaka had lived with the victims for a time as a teenager. 

In September 2020, Mihaka approached the victims looking for their son, believing he had stolen his car. They said they did not know where their son was. 

They received a call from a third party warning them Mihaka was going to burn down their home, and he later told the victims' daughter if he didn't get the car back he would burn the house down. 

Mihaka then called the victim and told her he was coming to burn her house down in the next couple of hours. 

It wasn't until several days later Mihaka showed up at the property in the early hours of the morning, poured accelerant around the outside of the house, and set it alight. 

He left the property without warning any possible occupants of the fire. 

"A neighbour was woken by a dog barking, managed to call emergency services and start dousing the fire," Judge Davidson said in his notes. 

The fire caused $70,000 of damage. 

"The victim impact statements reflect the breach of trust; as I have mentioned, they knew the defendant and had helped him some years ago. They, at the time, were very worried, scared, and apprehensive," he said. 

In court, the judge applauded the victims' bravery in showing up to the sentencing and speaking directly to Mihaka. 

"Their position, it seems to me, is very responsible, very tolerant, understanding and intuitive. Essentially they want the court to do its best to reduce the possibility of contact between you and them, but they have encouraged you to see today as a watershed moment in your life and build a better future for yourself and those close to you," he said. 

He sentenced Mihaka to 20 months in prison, but noted he would be released "almost immediately" due to the amount of time spent in prison pre-sentence. 

Judge Davidson also ordered six months of post-sentence conditions, including that Mihaka not contact the victims or enter their street, and that he pay $150 reparation for the insurance excess.