A woman wearing a traditional "mantilla" dress takes part in an open-air mass to celebrate Madrid's patron saint La Almudena Virgin in Madrid, Spain, November 9, 2015. (Photo by Susana Vera/Reuters)
An actor plays an injured passer-by during Exercise Strong Tower, the scene of a mock terror attack at a disused underground station in central London, Britain June 30, 2015. London police held their biggest-ever terrorism drill on Tuesday, pitting the emergency services against a group of marauding attackers, nearly 10 years since four young British Islamists killed 52 people in suicide bombings on London's transport network in July 2005. (Photo by Peter Nicholls/Reuters)
A South Korean soldier wear North Korea's military uniform, acting as North Korean soldier during an anti-terror and anti-chemical drill session held as part of the 2011 Ulchi Freedom Guardian (UFG) event on August 17, 2011 in Seoul, South Korea. The 11-day UGC, which features drills including the handling of chemical and biological attacks, is a regular joint exercise between US and South Korean troops to prepare for potential emergencies on the Korean Peninsula. (Photo by Chung Sung-Jun/Getty Images)
Girls play with their new dolls during the distribution of free toys for low-income families and a picture on the lap of one of the Three Wise Men at Almudena Cathedral in Madrid, Spain, December 22, 2015. Traditionally, children in Spain receive their presents delivered by the Three Wise Men on the morning of January 6 during the Christian holiday of the Epiphany. (Photo by Susana Vera/Reuters)
Green building also known as green construction or sustainable building is the practice of creating structures and using processes that are environmentally responsible and resource-efficient.