A growing number of North American architects and developers are supporting mass timber construction. Tall timber can sequester carbon, it's more resistant to fire than concrete, and it's often cheaper than using steel or concrete. Timber structures use large, prefabricated wood pieces.

But the process of building mass timber structures remains tough, because most cities place height restrictions on wooden structures.

In August, Oregon became the first US state to legalize mass timber high-rises, allowing wooden structures to rise above the previous six-story limit without special consideration.

With mass timber projects in many other cities pushing for approval and funding, take a look at some of the most prominent timber buildings in North America.