By Phoebe Armstrong and Joseph Harding

If you want to make an accountant panic, hand them the budget for a generational engineering project. But for an engineer, the astronomical size of the budget is a direct representation of the effort required to bend the built environment to their will.

The ambitious expenditure on display in create’s list of the most expensive infrastructure projects in history reflects the scale of the innovation involved in bringing them to reality. 

From a continent-wide transformation of a country’s transportation network that unfurled over close to half a century to a literally out-of-this-world outpost designed to handle the most extreme conditions, these projects show how the greatest endeavours have helped engineers push their creativity beyond the apparent limits of the possible.

We also consider an international effort to redirect waterways, a super-fast train connection completed in super-fast time, and a landmark moment in Australia’s infrastructure history that would change the course of the country’s future. 

Explore the five most expensive infrastructure projects in history and the engineering needed to bring them to life.

Explore the latest trends, innovations and best practices across construction at the Australasian Structural Engineering Conference 2026.