A man who beat children in his care with ropes and fishing rods had done so because he had "struggled to adapt" with new laws around child discipline, his lawyer said.

Pouleta Mano, 49, beat his two teenaged nieces while they stayed at the Napier house in which he lived with his wife, two other adults and four other children.

Mano pleaded guilty to two representative charges of male assaults female, two of assault with a weapon, and two of injuring with intent to injure, and appeared for sentencing in Napier District Court on Friday.

Mano beat the girls with ropes, fishing rods and other household items such as television remote controls when he felt they had failed in some manner, such as tidying the house incorrectly.

On December 18, last year, Mano and the family returned home from church and he demanded one of the girl's cellphone after hearing she had used it at church. He threw the phone on the floor, then demanded that both girls get out of their church clothing and come to the living room.

He had a length of rope in his hand and swung it very hard several times into the girls backs and legs. He then punched one of the girls in the face with a clenched fist.

Then he told his 9-year-old daughter to fetch scissors. He dragged one of the girls to the floor and cut her long hair to shoulder length. When she managed to kick him off he tried to cut the other girl's hair, but she was able to punch the scissors away.

The girls then ran to a bedroom and called police.

Mano's lawyer Philip Ross said Mano had struggled to adapt to "new rules" around how to discipline a child.

Judge Geoff Rea asked Ross "what new rules are there around whacking someone repeatedly with a hunk of rope?".

Ross said until 1990 both parents and school teachers could use reasonable force for the purpose of discipline.

At which point Judge Rea said "Mr Ross, before you start your submission, could you bear in mind that I have seen the photos?".

"Nobody is downplaying that. Least of all me," Ross said.

He said there had been a "significant change in society's approach and the legal framework", and Mano's offending reflected his approach to discipline within the family home.

Mano came from a rural Samoan community and had not fully assimilated into New Zealand culture, he said.

"He was effectively isolated within the community," Ross said

He said Mano had been through anti-violence programmes to address his offending, and he was "highly regarded in his community".

Ross asked for a sentence of home detention, as it would allow him to continue working as well as punishing him adequately for his offending.

Crown prosecutor Megan Mitchell said Mano had been bailed to the house where his victim's lived as none of the family members had anywhere else to live.

Rea was concerned that Mano was residing in the same address as the victims, and asked how this could be managed.

He said if a suitable address could be found then Mano could be sentenced to home detention. He adjourned sentencing to later this month. Mano was remanded on bail.