The plants were growing under high powered lights connected to a timer which was set to operate 18 hours a day.
Also found inside one of the growing rooms were 46 separate cannabis branches laid out to dry which had been harvested from a larger plant.
Bancroft told police he smoked up to four to five cannabis cigarettes a day and had done so for an extended period of time, and had been buying between a half to a full ounce a week but it become too expensive to source so began growing his own.
He denied selling any of cannabis to anyone but smoked some of his harvest with friends.
Bancroft claimed the cannabis was for personal use, a claim Judge Thomas Ingram told him he rejected. The judge said Bancroft would have to give evidence from the dock to persuade him of that. Bancroft was remanded on bail for a pre-sentence report and sentencing on June 15.
Meanwhile, rigger Lance Elli Williams, 33, of Judea was sentenced to nine months supervision and 80 hours community work after pleading guilty to a charge of possession of cannabis for supply.
The charge relates to Williams being caught with 20 small packets of cannabis totalling just over 400 grams when police searched his then-Papamoa home on March 29.
Meanwhile, unemployed John Niwa, 33, of Pyes Pa, who admitted five cannabis-related charges, was sentenced to nine months supervision and 40 hours community work.
That is for two charges each of possession of cannabis plants and possession of drug utensils, and one charge of cultivating cannabis.
Niwa was caught with three potted cannabis plants, 128 grams of cannabis leaf material, 59 seeds and two glass pipes for smoking cannabis and methamphetamine when police searched his Pyes Pa Rd address on March 19.