Architecture firm Rudiger Lainer and Partner has unveiled plans to build the world’s tallest wooden skyscraper in the Seestadt Aspern area of Vienna. The 276-ft, 24-storey HoHo tower will house a hotel, apartments, a restaurant, a wellness center and offices. Interestingly, 76 percent of the structure will be constructed from wood. The material choice, according to project developer Caroline Palfy of Kerbler, is largely ecological. While wood requires hewing down trees, its net environmental impact is far lower than concrete — construction would produce 2,800 tonnes less of CO2 emissions than an equivalent-sized concrete structure. The Vienna fire service has concerns about the wooden structure, however, and is working with the architects to test their plans.