RALEIGH - Wake County voters already facing a property tax increase from the school bond approved in the fall could be asked to dig deeper into their pockets for an extra $29.4 million to operate schools.

Citing record growth and state-mandated increases in salaries and benefits, Wake Superintendent Del Burns said Tuesday that he had no choice but to press for $29.4 million more from county commissioners for the coming budget year.

"We're concentrating on changes in the environment we can't control -- growth in the student population and state-mandated increases -- while maintaining our focus on teaching and learning for all our students," Burns said.

Burns said they're not asking for more than $29.4 million from commissioners because of the $970 million in school construction bonds Wake voters had just approved. He said the school system also is awaiting the results of an outside audit of the district's curriculum before recommending new academic programs.

Burns' proposed operating budget for the 2007-08 fiscal year will be reviewed by the school board. If the board approves, the school district would ask commissioners for $305.3 million of their $1.1 billion budget.

The question is: How much higher are the commissioners willing to raise taxes?

Last year, commissioners raised property taxes by 3 cents per $100 of assessed value, or $45 more per year on a $150,000 home. Much of that increase went toward fulfilling the school board's request for a $21.5 million increase.

Heading into the new county budget, taxes are already set to go up at least 3.4 cents, or $51 more per year on a $150,000 home, to help pay for the school bond issue and to open new schools this year.

In a preliminary budget, the county staff had set aside $297.1 million for the school district, a $21.3 million increase. Coming up with an additional $8 million to fully fund Burns' request could result in an additional tax increase of 1 cent, or $15 more per year on a $150,000 home.

Though the commissioners will likely not finalize the county budget for the next fiscal year until early June, Chairman Tony Gurley said he was open to the administration's $29.4 million request. By his calculation, it will take at least $18 million just to cover the growth from new students without factoring in any other costs. Because the schools are the county government's largest expense, he said, the commissioners will want to take a close look at whatever the school board eventually recommends.

"I'm fully aware it takes a lot of money to operate our schools and keep them at the level they are now and improve what we've got," Gurley said. "So we're not going to undermine their efforts; we just want to make sure that when they are spending that much that we're getting our money's worth."

But school board member Ron Margiotta was skeptical that commissioners would agree to a "healthy" 11 percent increase in school funding.

Patti Head, chairwoman of the school board, said its members have a compelling argument for asking for $29.4 million.

The message commissioners will hear repeatedly from school leaders is that the need for all the new funding is out of their control. Burns said 68 percent of the $29.4 million increase would cover growth-related increases and state-mandated increases.

The school district projects it will grow by 8,014 students this fall. Already at 128,072 students, Wake is the 21st-largest school district in the nation and will pass several more districts this fall.

Burns said $16.5 million in growth-related increases includes hiring more regular education and special education teachers to maintain class sizes and ratios.

Additionally, school administrators say they need $9 million from the county to absorb the local share of projected state increases for school employees.

"We're just looking at $29.4 million to maintain our current level of services," Burns said.

Pending the outcome of the curriculum audit, Burns said, administrators decided to focus on raising salaries instead of starting new academic programs. He said $4.4 million in new salary programs will help keep pay competitive and make employees less likely to leave the school system.

What is likely to be a controversial part of the budget proposal is a request for $3.3 million more per year to operate the 22 schools that will switch to a year-round schedule beginning in July. It costs more in salaries and utility costs because the schools will be open all year.

Some parents have been fighting the conversions, lobbying commissioners not to fund them. They're raising money for a potential lawsuit against the school district to block the conversions.

(Staff writers Kinea White Epps and Michael Biesecker contributed to this report.)