It's the perfect combination for Mr Hauser, who sees his decades-long fascination with Lego as an extension of ordinary life.

“You become a town planner, really," he said.

“And what's really great is seeing the kids faces light up when it’s all up and running. It’s quite amazing how it can transform into this masterpiece from just a few designs.”

Mr Hauser, who is working on the Wagga Base Hospital redevelopment, will be showcasing his Lego city at the Canberra Brick Expo next month.

The two-day charity event sees some of Australia’s best Lego collectors converge on the capital and it’s a hit with the kids.

It will be the fourth time Mr Hauser has taken his passion to the people – and with that passion comes some one million Lego bricks, 30 trestle tables and nearly 20 people working on set-up.

Zigzagging around the 10-metre L-shape design are trains, slot cars and miniature world sights such as the Arc de Triomphe.

Some of the trains are up to 40 years old.

“It’s remarkable that Lego has never changed the gauge of the track in all those years,” Mr Hauser said.

To purchase tickets for the August 29-30 event, visit brickexpo.com.au.