The Block NZ houses as judged by my nine-year-old nephew

Each year when The Block NZ rolls around, it seems like the entire nation has suddenly acquired a qualification in interior design.

Everyone's an expert when it comes to critiquing The Purple Team's tile choice, or the tone of The Blue Team's throw pillows.

Leading the charge in this respect is my nine-year-old nephew, Sam: a total Blockaholic who, when not singing the theme song, is bursting with opinions about the show.

With the final auctions just days away, it seemed an ideal time to bring Sam to Hobsonville Point to offer some last-minute insight on the team's tireless DIY efforts.

We head straight for the house of Sam's favourite duo: Ben and Tom. Much to Sam's delight, the boys are in the building.

"Claire and Agni need to learn to let things go - Amy and Stu don't always play fair and the girls are mushy, but you guys are just 'you'," he tells them.

I ask Sam to elaborate on his earlier off-camera comments that the boys could use better time management.

"What? I never said that!" he replies, with a carefully curated look of astonishment.

The Blue Team do lose a few points in Sam's book for over-styling their bedside tables, but his review is otherwise glowing.

Sam weighs in on the boy's choice of artwork.
Sam weighs in on the boy's choice of artwork. Photo credit: MediaWorks

Unsurprisingly, the kid's playroom in Amy and Stu's attic gets a perfect score, but not before Sam spends a full 10 minutes pretending he's in laboratory, for reasons best known to himself.

"This is beautiful!" he says, staring wistfully out of the skylight.

Despite having not yet reached double digits, Sam is particularly taken with the scullery in Claire and Agni's house - it was definitely worth sacrificing some cabinet space, he thinks.

Chlo and Em, despite using a "nice, warm" colour scheme in the master bedroom, are penalised for leaving a decorative pot on the bed - "it wouldn't be very comfortable."

Perhaps what sets Sam's judging style apart the most is his attention to detail. When a rather lovely bathroom receives a savage score of 5/10, I can't help but be a little shocked.

"Why?" I ask.

"No toilet paper," Sam replies.

The Block NZ final will screen this Sunday at 7pm on Three. It can also be viewed on ThreeNow