A rental appraisal found the market rate was between $340 and $360 a week, so $80 was reasonable, he said.
The tribunal, held in the Hastings District Court yesterday, heard that Whaitiri's parents sold him the house at a below-market rate on condition they could live there for the rest of their lives.
Mei Whaitiri's counsel, Scott Smith, said Meiand husband Wiremu, who died in 2015, were worried that, unlike his siblings, Jason Whaitiri, the youngest in the family, did not own his own house.
"They decided to sell it to him at a discounted price on the basis that they could live there for the rest of their lives.
"At a family meeting in 1998 his siblings raised concerns about their parents' future, and Jason assured them his parents could live there until they either chose to move or passed on - this agreement was not documented - they did not see the need at the time, which is regrettable," Smith said.
Siblings Meka Whaitiri, Robert Whaitiri and Joanne Rowe all told the hearing that several family meetings had been held about their parents' welfare, including seeking assurances from Whaitiri that they would be able to remain living in their family home.
The tenancy situation was formalised between Jason Whaitiri and his parents with a residential tenancy agreement in 2012, stipulating the rent to be $200 a week.
Jason Whaitiri said he did recall saying at a 1998 meeting his parents could stay in the house.
"I have made no assurances about lifelong occupation."
He said he was saddened it had come to this point, while negotiating the increase in rent.
"What I wanted was a tenancy agreement for market rent and Mum could live there but the allegations about life tenancy are disturbing for me - it's clouded the issue."
After the hearing he said all the proper protocols had been followed since engaging the property manager.
"It's sad for us because now there's a rift in the family."
Adjudicator Bryan King reserved his decision.
Meka Whaitiri said it was a "sensitive time" for all involved.
"We want to respect the tribunal process. It is a personal family matter and I want what is in the best interest of my 79-year-old mother."