The site plan for the Wentzville School District's third high school calls for the building and stadium to be centrally located on the property, thereby minimizing the impact on neighboring subdivisions.

The central location allows retaining trees along the property lines to the west and north, which would help buffer the school site from residential neighbors, officials said.

The Board of Education on Thursday unanimously approved the master site development concept plan submitted by the administration steering committee and design team.

The committee took into account the existence of homes near the site, said Matt Deichmann, district director of school/community relations.

"They wanted to be as considerate as possible," he said.

The district expects to begin construction next year, possibly breaking ground in early spring, on a 79.6-acre site on Sommers Road between highways N and DD in O'Fallon. The district bought the land for $5.9 million in July.

Approval of the site plan allows the committee to continue with the permitting process and the design of the school building.

According to the plan, the school will be on the northern half of the property, with bus loading and staff parking behind the building, and student and visitor parking in front. The activity complex would be on the southern half, with athletic fields, parking and an admission/concession building annex.

The plan provides three access points along Sommers Road, two on the building half of the site and one near the activity complex. A loop access road to be built around the entire perimeter of the property would allow various options for traffic control.

"We have been meeting every week since we bought the property, and have had some very extensive and constructive conversations," said Superintendent Terry Adams. "We feel this is the most cost-effective and efficient use of the site, and we look forward to building a quality educational facility for our students."

Voters last April approved a property tax increase of 30 cents per $100 assessed valuation to pay for a new high school and additional classrooms at several elementary and middle schools. Proposition 3 is expected to provide $36 million to $40 million for the high school. The district bought the land with money from a 2008 bond issue.

The new high school, which hasn't been named, is scheduled to open in the fall of 2013 and tentatively planned to serve freshmen students the first year and freshmen through seniors within four years. The school could accommodate about 1,200 students.

"But as you know, we are the fastest growing school district in Missouri, and there is the possibility that later add-ons would increase that to about 1,600," Deichmann said.