Nevada’s state energy director wants to require building owners seeking to take advantage of the state’s large tax credits for energy-efficient buildings to ban smoking, the Associated Press reported.

The proposed regulation, which requires approval by the state’s Legislative Counsel Bureau, could apply to casinos. In 2005, the state began offering tax breaks of about 30 percent to construction projects that follow the U.S. Green Building Council’s Leadership in Energy and Environmental Design regulations. The guidelines, which set minimum standards for conservation, air quality and related “green” goals, require smoking be banned or only permitted in separately ventilated and enclosed areas.

Nevada’s original tax credits exempted casinos from the nonsmoking rule. But in updating the law this year, the state Legislature added the smoke-free requirements to all structures, Nevada Energy Director Hatice Gecol told the AP.

The tax breaks are worth millions to projects such as Echelon Place, a $4 billion casino resort complex expected to contain thousands of hotel rooms and more than 750,000 square feet of meeting space scheduled to open in 2010.

Boyd Gaming, which is building Echelon Place on the site of the former Stardust resort, said its project is grandfathered under the old regulations.

Anti-smoking activists, however, are pushing to have any projects seeking LEED certification and the state’s tax credits made completely smokeless.

In 2006, they pushed through a ballot initiative amending the state’s Clean Indoor Air Act that banned smoking in almost all public places. Casino gambling areas are exempt.

A final regulation is not expected to be in place until late September or early October, state officials said.