Microsoft has started building data centres using fire-resistant wood in an effort to cut carbon emissions and use more climate-friendly building materials.

Engineers are using a material known as cross-laminated timber (CLT) in combination with steel and concrete, which it estimates could reduce the embodied carbon footprint of two new data centres by 35% compared with conventional steel construction, and 65% compared with typical precast concrete.

Because engineered wood is naturally low in carbon, abundant and easy to manufacture, CLT has been in increasingly wide use in the US and Europe, where it has been a staple of green building for at least a decade. In 2021, Microsoft built its new Silicon Valley headquarters out of CLT, as part of the company’s first large-scale use of the material.

CLT is made by gluing together three to nine layers of timber stacked in alternate directions, and then pressing them into a solid panel. Unlike steel, which deforms and fails more quickly under high...