High-rise wooden buildings, led by The Tree, a 52.8-meter (173-foot) apartment block in Norway, are claiming a place on city skylines as the timber industry challenges the supremacy of concrete and steel.

New, ultra-strong wood materials are creating a small but fast-growing market for timber used to build big, urban blocks, extending wood's uses beyond the houses typical of Alpine villages or suburban America.

Backers of timber towers say they are greener than concrete and steel, whose production emits large amounts of greenhouse gases. Those industries say felling trees harms the environment if it causes loss of forests.