Everybody seems to be an activist on Earth Day. However, there are a number of big homebuilders that enforce sustainability efforts on a regular basis.

KB Home [stock KBH][/stock], for instance, has delivered more than 1,000 solar homes, opened new ZeroHouse 2.0 model homes (net-zero-energy homes) and introduced new water efficient standard products. 

Lennar [stock LEN][/stock] has delivered more than 1,600 solar powered homes since 2006, producing nearly four mega watts of total solar power, according to the company’s website. 

Pulte Homes [stock PHM][/stock] is also working on a number of projects and initiatives in an effort to use more sustainable products, conserve more water, reduce waste and minimize the impact on natural resources, the company’s website states. 

Toll Brothers [stock TOL][/stock] claims to use improvements in technology and the increasing availability of green products to make their homes. When a homeowner chooses a Toll Brothers green home, not only does it save them money but it includes more efficient gas furnaces and air conditioners, sealed duct work to prevent air leaks, Low E windows to keep cold out during winter, etc.

In 2008, the National Association of Home Builders launched NAHBGreen, a program which helps builders, remodelers, developers and homeowners/buyers to build and understand high performance construction and development. NAHBGreen provides a suite of services for and educational resources, including the Certified Green Professional, Master Certified Green Professional, International Builders’ Show and webinars. 

For those looking to rehabilitate their existing homes, companies like The Home Depot [stock HD][/stock] and Lowe’s [stock LOW][/stock] offer a number of tips and products to help homeowners create a more environmental-friendly house.