All of these structures are made from wood, but not the traditional two-by-fours you're thinking of. These buildings make use of innovative new materials like glued-laminated timber (glulam) and cross-laminate timber (CLT), both of which are gaining in popularity. They're part of a family of materials named mass timber, where wood is cut, stacked, and glued to make a strong material even stronger. It's cheaper, performs better in earthquakes , and is far more sustainable than most building methods out there now. It's also made here in the US -most mass timber products come from Southern Oregon.