If Abraham Lincoln's house can go green, anyone's can. President Lincoln's Cottage, his family's summer retreat during the Civil War, has been completely renovated during preparation for the compound just a few miles from the White House to be opened as a national monument. But it wasn't done as just any restoration of an old house, it was kept as green as possible.

To that end, Time magazine recently reported that renovators kept 98 percent of the existing structures and used recycled material for the rest. The buildings earned a gold rating from the U.S. Green Building Council, thus proving that going green doesn't mean it has to be a completely new house. In fact, greening an existing home is far more environmentally viable.

The Austin real estate market ranks in the top ten nationwide for building green homes. According to a recent Austin-American Statesman article, more than 20 percent of the homes built in Austin are rated green by Austin Energy's Green Building Program. And that's not expensive homes. "One of the interesting things that's happening in Austin is, early on back in the 1990s, everybody assumed green building would be for high-end custom homes, but now probably about 90 percent of what we rate are built by production builders. In most places, it's the custom builders doing green, but here, the production builders have really adopted green. And that is something that's unique to Austin," said Richard Morgan, manager of Austin Energy's program.

Of course not everyone is going to go out and buy a newly built green home. While a new home is more energy efficient than an older home, those who own an older home don't have to give up on being green. As reported in Time, homes built before 2000 generally use 50 percent more energy per square foot, largely do to all the heating and cooling that escapes through the multitude of tiny cracks and crevices in older homes. A good place to start being green, as well as saving some green, is by getting out the caulking gun.

If it's time to replace any bathroom fixtures, the U.S. Environmental Protection Agency has a WaterSense certification system, which can help consumers choose toilets and other products with better water efficiency. The Energy Star program helps consumers choose energy-efficient appliances and other products.

Both green building and green renovations have the potential to create thousands of jobs. The Obama administration included $8 billion in the stimulus package for weatherization of low income homes. That will only scratch the surface of covering the costs for greening a homes across the country. The National Trust is working with members of Congress to create legislation that would offer rebates and incentives for things like installing better insulation or energy efficient windows.

However, if you don't want to wait on Congress, there are small things homeowners can do now to make houses more energy efficient. A good place to start is a home energy audit. The website energysavers.gov offers do-it-yourself tips.