His appeal was also against Auckland Council, Wilkinson Building and Construction - who were involved in the failed 2004 and 2005 repairs - and others.
The case was heard last July.
In the High Court decision, Justice Patrick Keane said Holyoake's Hitex had completely reclad the place before the couple bought it, but that job using his "unique proprietary product Hitex 50" cladding had failed because timber framing was moist or wet, some was already decayed and there was mould.
Auckland Council's expert Clint Smith said that was not because Hitex 50 was inherently unsound but because of poor workmanship. He estimated a full reclad would cost $385,337.
The judge refused to overturn the tribunal's 2012 decision which ruled the couple are owed $433,087: $385,337 for remedial work, $22,750 for the loss of rent and $25,000 general damages.
"I conclude that the tribunal made no error in its liability, remedial scope, quantum and costs decision," the judge ruled.
Holyoake was liable with his Hitex for 73 per cent of the Zagorskis' damages award, just as the tribunal had ruled, he said.
The judge traced the history of the case, saying that in 2006, the couple had received a favourable pre-purchase report from Allied House Inspections. That report told them there were moisture probes throughout the house.
In 2010, they planned to return to Australia so decided to sell and got a report from a different assessor who said to go to Holyoake's business, the Moisture Detection Company, which had put the probes in the walls before they bought.
"The Zagorskis then discovered that the house had been moisture tested on 18 May, 2006, 10 days before they entered into the agreement for sale and purchase with the Wilkinson trustees and that some moisture readings then taken had been as high as 80 per cent and one third had been 18 per cent or higher," the judge said.
Holyoake argued that the Zagorskis bought the place knowing it had leaked in the past, had remedial work and ought to have been aware of the probes. Their failure to have readings taken before deciding to sell in 2010 contributed to the damage worsening, he said.
Leaky home liability
Fancourt St, Meadowbank, Auckland:
1990s: House built and earlier last decade Wilkinson trustees buy it
2004-2005: Big leak repairs carried out by Wilkinson Building and Construction and Ian Holyoake's Hitex
May 2006: Holyoake's moisture probes show 80 per cent readings but Zagorskis pay $913,000
2010: Zagorskis decide to sell, investigate and go to Weathertight Homes Resolution Service
2012: Weathertight Homes Tribunal awards them $433,087, 73 per cent from Holyoake
July, 2013: Holyoake goes to High Court at Auckland seeking to overturn tribunal decision
March 14, 2014: Court upholds tribunal ruling that Zagorskis must get $433,087
[Source: Justice Patrick Keane decision, High Court at Auckland]
