U.S. Senator Charles Schumer of New York proposed a federal code for new building construction requiring energy efficiencies that he said may cut waste by 30 percent nationwide by 2012.

Schumer said he would introduce the bill next week as an amendment to an energy bill now before the Senate. The measure, which Schumer predicts may reduce U.S. energy use by 5 percent and save consumers $50 billion a year by 2030, would give $125 million to states to help them implement the new building codes.

``The best way to reduce greenhouse gases is conservation even though alternative fuels get most of the attention,'' Schumer, a Democrat, said at a news conference today in midtown Manhattan, where he was joined by Mayor Michael Bloomberg and developer Douglas Durst, co-president of the Durst Organization.

Buildings account for about 40 percent of all energy used across the U.S., and more than two-thirds the electricity generated in the U.S. goes to heat, cool and power buildings. This produces tons of carbon gases in the atmosphere, a cause of global climate change.

Durst, who built the Conde Nast Building at 4 Times Square in 1999 as New York City's first ``green building,'' said lower energy costs meant he made up the added expense of installing solar panels, heat-resistant windows and other conservation devices within five years. Schumer said cumulative cost savings for home and business owners from the new code may be as high as $435 billion by 2030.

Green Code

Schumer said he modeled his building code on similar laws enacted in California and proposed last month by Bloomberg for New York City. The mayor said his ``greening of the code'' would include rewarding companies that use new technology to cut energy use and conserve resources.

Schumer's bill calls for $125 million to help states conform to the national model regulations over the next two years. States unable to achieve 90 percent compliance in that time could be granted a one-year extension, he said.

Bloomberg, a Republican, said he wanted the New York state Legislature to create an ``energy efficiency authority'' with the power to enact surcharges on electrical rates to create funds that would help builders retrofit existing buildings to conserve energy.

The mayor is founder and majority owner of Bloomberg LP, parent of Bloomberg News.