EDGEBROOK — Wildwood Elementary School's new three-story, $15 million annex will built on what is now Wildwood Park's basketball court and water play area, according to plans unveiled Tuesday.

Wildwood Principal Mary Beth Cunat said she was thrilled with the design for the annex, which will include a new lunchroom/multipurpose room, 12 classrooms, a computer lab, library, art room and administrative offices.

"We are just beyond pleased and just so excited," Cunat said after exchanging looks of incredulous joy during the presentation by Public Building Commission Executive Director Erin Lavin Cabonargi with teachers at the award-winning school. "It is just so great."

Mayor Rahm Emanuel announced in September that Wildwood would get an annex after years of lobbying by school officials and parents fed up with overcrowding at the Edgebrook school, which forced students to eat lunch at their desks and often study in the hallways.

Although though the main building was meant for 240 students, 424 students are enrolled at Wildwood. That gives the school a utilization rate of 177 percent, one of the highest in the city, according to CPS data.

Even with a four-classroom modular building, the school has an adjusted utilization rate of 128 percent, which is still considered overcrowded, according to data provided by CPS.

Construction of the annex, which will double the size of the school, is expected to begin in August, and be completed in time for the first day of school in September 2015, Lavin Cabonargi said.

The building will have a steel frame with a brick exterior, Lavin Cabonargi said. The building will be designed to allow as much natural light as possible into classrooms and hallways, she added.

Seven different plans for the annex were considered for the school at 6950 N. Hiawatha Ave. in order to accommodate the homes directly across the street along Mendota Avenue and to maintain as much of the park and its open space as possible, Lavin Cabonargi said.

Plans to build the annex directly across the street from the homes on Mendota Avenue were rejected because of the desire of nearby residents to keep the recently-resurfaced tennis courts and other objections from those homeowners, Lavin Cabonargi said.

While most annexes recently built for overcrowded Chicago Public Schools have been two stories, Wildwood's will be three stories because of the school's small footprint and the community's desire to maintain the park's much-used baseball fields, Lavin Cabonargi said.

Construction will not start until August in part to allow Fourth of July celebrations to be held in the park and for the baseball season to take place, Lavin Cabonargi said.

A fire lane that will resemble a walking path through the park will allow emergency vehicles to get to the annex without building a road through the park, Lavin Cabonargi said.

There are no plans to replace the basketball courts or snake-shaped water spray play area on school property, Lavin Cabonargi said.

A spokeswoman for the Chicago Park District did not respond Tuesday to questions about whether the court and the water spray feature would be replaced elsewhere in Wildwood Park.

In response to questions from parents about traffic surrounding the school, Lavin Cabonargi said a plan would be developed by an engineer to determine the most efficient route for pick up and drop off both during and after construction.

Enrollment at the school, which offers a magnet program and an International Baccalaureate curriculum, is expected to grow for the next three to four years, Cunat said.

Plans for the annex will be considered May 15 by the Chicago Plan Commission and May 22 by the Chicago City Council Zoning Committee, Lavin Cabonargi said.

For more neighborhood news, listen to DNAinfo Radio here: