on this building. Around 2010, the Empire State Building underwent a $550 million renovation, including $120 million towards energy efficiency and eco-friendliness. It received a gold LEED rating in 2011, and at the time was the tallest LEED-certified building in the United States. The Coastal Maine Botanical Gardens Bosarge Family Education Center, completed in 2011, achieved LEED Platinum certification and became known as "Maine's greenest building". In October 2011 Apogee Stadium at the University of North Texas became the first newly built stadium in the country to achieve Platinum-level certification. In May 2012, Soldier Field in Chicago became the first National Football League (NFL) stadium certified LEED. In July 2014, the San Francisco 49ers' Levi's Stadium became the first NFL venue to earn a LEED Gold certification. The Minnesota Vikings' U.S. Bank Stadium equaled this feat with a Gold certification in Building Design and Construction in 2017 as well as a Platinum certification in Operations and Maintenance in 2019, a first for any professional sports stadium. In September 2012, The Crystal in London became the world's first building awarded LEED Platinum and BREEAM Outstanding status. It generates its own energy using solar power and ground-source heat pumps, and utilizes extensive KNX technologies to automate the building's environmental controls. When it received LEED Platinum in 2012, Manitoba Hydro Place in downtown Winnipeg was the most energy-efficient office tower in North America and the only office tower in Canada with a Platinum rating. The office tower employs south-facing winter gardens to capture solar energy during the harsh Manitoba winters, and uses glass extensively to maximize natural light. In San Francisco's Presidio, the Letterman Digital Arts Center earned a Gold certification. It was built almost entirely from the recycled remains of the Letterman Army Hospital, which previously occupied the site. Torre Sul of Green Tower Brasilias received LEED Gold certification in 2014. In the public retail area on the first floor, visitors can see the largest green wall in Latin America, which is high. In 2017, Kaiser Permanente, the largest integrated health system in the United States, opened California’s first LEED Platinum certified hospital, the Kaiser Permanente San Diego Medical Center. By 2020, Kaiser Permanente owned 40 LEED certified buildings. Its construction of LEED buildings was one of multiple initiatives that enabled Kaiser Permanente to report net-zero carbon emissions in 2020. Criticism In 2005, Auden Schendler and Randy Udall, respectively a LEED-accredited professional