The Fire Investigation Report, released to the Otago Daily Times under the Official Information Act, was prepared by Fire Risk Management officer Stu Ide.
In it, he said the flue and casing failed to meet the minimum requirements of the New Zealand Standard on possibly more than four points.
''If the fire had not occurred at the top of the chimney, it may only have been a matter of time before a fire would have developed in another area associated with incorrect installation.''
Mr Ide said it was the fourth fire in the Wakatipu since 2003 caused by incorrect flue installations.
Others were at the Blanket Bay resort on December 1, 2003, and two private dwellings, one at Dalefield and another in Jacks Point, in 2012 and 2013 respectively.
On August 10, the Frankton Volunteer Fire Brigade responded to a chimney fire at the clubhouse at 8.12am. Within 30 minutes the fire developed, with a second alarm transmitted at 8.36am.
The fire appeared to have been ''knocked out'' at 8.59am, but about 9.20am it grew out of control again and was not fully contained until 9.55am.
As a result, the clubhouse restaurant was closed for
two months and the golf
course had opened six weeks later than planned.
Mr Ide found the initial fire started where the flue passed through ''a non-combustible material'' at the top of the chimney enclosure.
''It is most likely that a [build-up] of the by-products of combustion had accumulated on the flat surface below the cowling where the flue is terminated.
''Terminating a flue so close to this flat area contravenes [New Zealand Standards].''
Once the particles of soot had ignited, the temperature of the non-combustible material under and around the cowling would have increased.
A wooden surround inside and outside the chimney enclosure meant it was likely the heat would have transferred through the material to the wood by conduction.
The wooden enclosure was likely to have been ''extremely well dried out'' with the heat of the flue and casing over the past decade.
''Therefore, this would have taken very little extra heat to ignite the wooden enclosure.''
The report said after the three fireplaces were installed they did not draw properly.
A hole was cut into the mezzanine floor of a room called the plenum - designed as a cavity to take air in - about halfway up the flue cavity of the fireplace on the east side of the building.
A pipe was inserted into the hole and a fan was positioned to push air down the hole.
The plenum, measuring about 1.4m by 5m, also held an air-conditioning unit and seven light ballast boxes and had, over the years, become a ''storage room''.
Items in it included computer towers, monitors, boxes, cushions, life jackets, signs, a large roll of plastic, glasses and clothing.
''Information received from the CEO of the clubhouse indicated that he went to store items in the plenum a week prior to the fire and it was full: 'There was no room for anything else'.''
Mr Ide's report said because access to the top of the chimney enclosure was not possible at the time of the fire, there was an extended burn time above the plenum.
''When the ceiling of the plenum failed, possibly due to burnt timber falling through, there was ample fuel loading in the plenum to allow for a second development of fire.''
Further fuel was likely added by a refrigerant gas associated with the heat pump.
''Based on the evidence available at the time of this investigation, the classification of this incident has been recorded as 'accidental','' Mr Ide said.
