Jacinda Ardern's partner Clarke Gayford builds new deck in the thick of parenthood

Jacinda Ardern's partner Clarke Gayford has proven wrong those who doubted him and constructed a deck outside his house while in the midst of new parenthood.

News presenter Amanda Gillies has remarked in June that Mr Gayford was "dreaming" if he believed he could build his deck once the baby had arrived.

But six weeks after baby Neve was born Mr Gayford proudly showed off video evidence of the deck, which included a step, and even got the praise of The AM Show's sports presenter Mark Richardson.

"It was done, I have to say, with a lot of assistance on my part," Ms Ardern said. She didn't do any work on the deck itself, but Ms Ardern says she helped take on other work while Mr Gayford was at work building.

"On the deck, absolutely nothing, but had I not been caring for Neve he wouldn't have got away with it that's for sure," she said.

Mr Gayford admitted the construction took place at some funny hours, saying in the video that he was out in the backyard with the deck at 4am.

He also sacrificed "sleep and personal grooming" to build it. Ms Ardern said she would have to offer an apology to her neighbours for the building as Mr Gayford had often been outside hammering late into the night.