FILE--In this Nov. 15, 2016, file photo, structural engineer Eric McDonnell shows diagrams of skyscraper construction using cross-laminated timber, or CLT, at Portland State University in Portland, Ore. City officials in Portland have approved a construction permit for the first all-wood high-rise building in the nation. The building uses the new technology called cross-laminated timber that tests have shown can withstand the worst earthquakes. Developers worked with scientists at Portland State University and Oregon State University to prove through testing that the materials meet all building and fire safety codes. (AP Photo/Don Ryan, file)
Featured Photo Galleries
