Some people think that the term "environmentally friendly" is just another way to say expensive, but a 2006 study by the U.S. Green Building Council (USGBC) found that, at least with new construction, going green won't cost more green [source: Llewellyn]. In fact, energy-efficient construction can drastically cut utility bills, so it's no wonder that green building is now a multibillion-dollar industry and getting bigger every year [source: Llewellyn]. A study conducted by consulting firm Booz Allen Hamilton estimates that over the period from 2009 to 2013, green construction will contribute $554 billion to the U.S. GDP [source: USGBC].
As the market for green building grows, demand for consultants on the subject will increase as well. These consultants will be responsible for everything from advising builders on which green building techniques to use for a project to certifying that a project meets any of the increasing number of green building standards now in place. But while these positions aren't physically demanding, they do require some expertise in the building profession. Retirees who previously worked as architects, engineers or construction project managers are particularly suited to the work, but even with that experience, they'll likely need to take courses on the latest green building techniques, policies and regulations. For their efforts, green building consultants can earn upward of $50,000 a year, particularly if they receive LEED or other industry certifications [source: Indeed.com]. Once they're up to speed, however, they can start building a brighter future for both themselves and the planet.