New environmental standards will increase the cost of Columbus' 15-year school-construction plan, but also could improve long-term energy costs and student learning, a school district official says.

The state requirement will add about $500,000 to the cost of building each new elementary school, which will have to meet standards in energy efficiency and environmental sensitivity, Columbus schools facilities executive Carole Olshavsky said.

The Ohio School Facilities Commission, which helps fund and manage Columbus' half-billion-dollar school-construction program, recently adopted construction standards set by the Leadership in Energy and Environmental Design for Schools Rating System.

New schools will be measured in several areas of environmental friendliness, including air quality, natural light and acoustics. The LEED certification will add between $500,000 and $600,000 to the cost of the average $8.5 million elementary school building.

"There's certainly a long-term benefit," Olshavsky said. "That's an insignificant cost if you look beyond the immediate building. If you look at the global impact, that's negligible."

The LEED system was created by the nonprofit U.S. Green Building Council and provides certification for "green" buildings. The standards would apply to future phases of the district's building program.

The district is nearing the end of the first phases, which will have renovated or reconstructed 34 schools. The first phases, funded in part by a $392 million bond issue passed in 2002, are expected to be completed in summer 2009. Olshavsky told the school board last month that the projects have been completed largely on time and on budget.

The next phase of the building program was expected to begin in 2009, but the timeline is now uncertain.

Voters must pass another bond issue by November 2009 to avoid dismantling the staff that runs the building program, an adviser has told school officials. The school board has not yet decided when it will place another bond issue on the ballot.