Shane Stone said he was proud of how far Mancer had come in his time as an apprentice.
"He's a young confident guy and he's just owning it at the moment," Stone said.
He said Mancer had recently been put in charge of a $700,000 job with more experienced people working under him.
Mancer said the first step of the competition was to submit a 2000-word portfolio of a building project he was currently working on or had already completed.
Then he went to Palmerston North where competitors were tasked with building a saw horse in two hours.
"We had about three minutes I think to look over plans before work commenced," he said.
The top 10 competitors were selected for the second stage of the competition, which involved the competition's judges conducting a 45-minute interview of Mancer's knowledge as an apprentice.
The judges then visited the site of the project Mancer had submitted originally.
"We either had to be there for the practical or we were disqualified if we didn't meet the site visit or have our submission in by the time we were disqualified straight away, so there were very strict criteria," Mancer said.
Mancer moves on to the national competition, against the seven other regional winners later this year.
The national competition will involve a similar process, but Mancer will have to outline a different, smaller project from start to finish, with photos included.
He will then fly up to Auckland to take part in a six-hour practical challenge in front of a large audience on November 14, before a 45-minute interview the next day about the project he submitted.
"I kind of know what I'm getting myself in for, I've already met the judges so we know who they are... I kind of know the scope and what questions they're going to be asking and how to prepare myself a lot better than how I did the first time."
