An environmental group wants Virginia officials to require new homes to be more energy efficient.

Environment Virginia says a building code revision by the state Department of Housing and Community Development would increase energy efficiency in homes by 15 percent.

The group wants the state to adopt the International Energy Conservation Council's model code.

A state housing spokesman says the agency is considering that and other models and plans to revise regulations by September 2010.

Environment Virginia released a report Wednesday on the benefits of energy efficiency at a house the city of Charlottesville is renovating to make it close to net zero energy use.

A spokeswoman says 63 percent of Charlottesville's greenhouse gas emissions come from existing buildings.