|Germany has some of the strictest building codes and sustainable energy-encouraging laws in the world. The country requires energy-efficiency upgrades to buildings and increased use of renewable energy sources among electricity providers. It also provides financial incentives through subsidies and loans to reduce energy consumption in buildings at all levels of government; at the national level, the funds come from a public investment bank, created for this purpose, sponsored by the German government. The country tries to promote these projects through energy performance certificates and by supporting model projects across Germany.
Some American cities have also pushed sustainable building design — New York City and Portland, Oregon, are two notable examples — as well as many states. Nonprofit groups have also sought to encourage green building through LEED certification. (You can search for a green, LEED building near you.)