The Chevrolet Volt extended range electric vehicle with a 230 miles-per-gallon rating, is shown in front of the GreenHouse, a custom-built 4,000 sq-ft "carbon neutral" house in MacLean, Virginia Tuesday, September 22, 2009. The Volt will travel 40 miles on a single charge, meaning it could drive to Washington, DC and back twice from this location, without using a drop of gas. GreenHouse was designed and constructed using the latest environmental technologies, including solar hot water and electricity, a green roof system, rain water capture, geothermal heating/cooling and much more. The house will be open to the public for tours October 10-30.