Energy conservation, which the government has implored citizens to practice, does not always start at home, according to a report released yesterday by environmental campaigners, which found that public buildings wasted more than 100 million euros a year in excessive energy bills due to poor insulation. After a study on the energy efficiency of public buildings in 23 European capitals, with the help of thermal imaging, Greenpeace found that Greece was among the worst offenders, with a building belonging to the Public Power Corporation (PPC) in central Athens being a prime example because of poor insulation and design. Campaigners found that the state spends over 450 million euros each year on energy for some 200,000 buildings which it owns. With better conservation, environmentalists claim, this bill could be reduced by about 110,000 euros a year and carbon dioxide emissions could be cut by some 425,000 tons annually in the process. Greenpeace asked for a law to be passed requiring the private sector to conserve 2 percent of the energy it uses each year and the public sector to save 2.5 percent.