Tearful families spat insults at each other as a Dunedin builder was jailed for nearly 15 years for the prolonged sexual abuse of his stepdaughter.

The 47-year-old, who was found guilty of eight sex charges following a jury trial in May, was labelled a ''monster'' by one sobbing woman in the back of court as he was led to the cells at the Dunedin District Court yesterday.

Supporters of the defendant - who was granted permanent name suppression to protect the victim - yelled ''I love you''.

One woman stood in the public gallery and shouted at Judge Kevin Phillips: ''[He] is innocent''.

The family of the victim, who was abused for more than five years in various ways, bit back, and as they left the court there were further emotional exchanges as police and court security formed a barrier between the angered parties.

Defence counsel Andrew Dawson said his client maintained his innocence and his family could not reconcile the sex crimes with the man they thought they knew.

At trial, the court heard how the defendant first targeted his stepdaughter in 2010 in the early hours following her 11th birthday.

He snuck into her room, removed her clothing and raped her while telling her to shut up.

Judge Phillips noted the defendant held the girl down by the neck and she had felt pain for days afterwards.

The victim told the jury how she disposed of the soiled bed sheets the next day.

There was premeditation to a moderate level in the attacks, the judge said.

''You relentlessly carried out your offending in the victim's home, at times when you were alone with her, at times when everyone else was asleep,'' he said.

On one occasion, the victim was home from school because she was sick.

Her mother had left to buy her some ice blocks and while they were alone, the defendant forced her to perform a sex act.

It ended abruptly when the woman returned from the shops, the court heard.

''She's extremely damaged, if not in fact destroyed,'' Judge Phillips said of the victim.

A statement she wrote underscored her fear, her pain, and her nightmares and flashbacks, and discussed the loss of her relationship with her mother.

The girl had kept quiet about the ongoing violations to protect her mother, she said.

The judge called her ''an extremely brave young person''.

''She intends to survive ... to complete her journey to her future without the fear of you.''

He said the offending was near the worst end of its kind.

''You took advantage of her on a regular basis over many years.''

Dawson said there was no need to impose a minimum non-parole period because it would be some years before there was any chance of his client being released.

He called the offending ''context specific'' and suggested there was no need for wider protection of the community.

The defendant had no previous convictions.

But Judge Phillips disagreed.

It will be seven years and four months before the man is eligible for parole.

He was placed on the Child Sex Offender Register.