Once upon a time Lego was just a pile of bricks and some imagination - now all manner of elaborate themed sets are available. But what's more creative, basic blocks or blueprints?
Professor Brenda Vale and her husband, Dr Robert Vale, both architecture academics, are keeping it old-school and say an instruction-free approach to playing with construction toys is the best.
The Victoria University researchers say modern toy construction sets don't teach children sound engineering principles or inspire creativity in the way that old sets did.
New-generation plastic toys, such as Lego and K'nex, are made to clip together, letting children build things that should not logically be able to stand up.
"This means children are missing out on learning about structure, which is the foundation of architecture," Prof Vale said.
The advent of movie-themed Lego, such as Harry Potter and Lord of the Rings sets, had seen a move away from Lego as a generic product used as a free-ranging creative canvas, to a world of prescribed setpieces.
The Vales, authors of Architecture on the Carpet: The Curious Tale of Construction Toys and the Genesis of Modern Buildings, are keen construction toy collectors. They say many 19th and 20th-century sets taught children about architectural concepts - including modularity and load-bearing construction.
Vintage sets they looked at included Lego, Meccano, Richter's Blocks, Lincoln Logs and Minibrix.
Modern construction toys were also curbing creativity, with sets designed to build just one thing, and instruction booklets that were too detailed and prescriptive. Older sets often featured several design ideas and minimal instructions, requiring greater skill from the user, Dr Vale said.
Previous research by the couple found that dogs have a bigger carbon footprint than cars.
Renowned Wellington architect Ian Athfield played with Meccano as a boy. He said individual children responded differently to construction toys and those who liked them learned valuable lessons about the intricacies of assembly and detail.
Lego enthusiast and Toyworld Wellington owner Phillip Bramley said he agreed with the architects - up to a point.
"Fundamentally what they're saying is not wrong. Lego's just evolved to a different point, but it's not better or worse."
As for learning about engineering from big setpieces, he said look no further than Lego's multi-room, 40cm-diameterStar Wars Death Star.
"If you don't build it properly, it's going to fall apart - you can't tell me the Death Star doesn't have structural integrity."
Whitby father Paul Kennedy's sons Jackson, 9, and Austin, 6, love playing with Lego and although they used basic blocks more creatively, setpieces were equally inspiring once constructed because they fuelled an ongoing fantasy world.
"If creativity and imagination are the same thing, there's no downfall in the sets - these guys will imagine themselves in that world for days."
- The Dominion Post