Developer Cousins Properties is planning to request the rezoning of a 37-acre tract at the top of Lost Creek Boulevard from single-family residential to a commercial planned unit development in the next 60 to 90 days, Cousins Properties' attorney Steve Drenner said.

Jennifer Lamm, president of the Lost Creek Neighborhood Association which represents the homeowner near the proposed development, said Tim Hendricks, vice president of development for Cousins Properties, notified the LCNA board members in March that the tract was under contract.

Hendricks told LCNA board members the proposed project may include two multistory office buildings, one or two parking garages and an assisted-living center, Lamm said. Access to the site is planned through an easement on the adjacent Las Cimas commercial property, she said.

Lamm said she told Hendricks the association was concerned about the building height and setbacks for the development. A cemetery on the tract would also need to be protected during and after development, she said.

Some Lost Creek residents voiced concerns about the plan to develop the 37-acre site—known as the Marshall Tract—during a special meeting with Austin City Councilman Mike Martinez on May 24.

Residents said they were concerned about what impact the added traffic to the complex would have on the area as well as the aesthetics of an office building in the neighborhood and maintaining open space in the community.

"It will be a big development in our little neighborhood that we've taken such good care of," said Cindy Edwards, who moved to Lost Creek in 1988. "People who back up to it will be staring at an office building instead of [a] greenbelt."

Lamm asked Martinez what rights the neighborhood may have to determine the type of project built on the property. She said although the Marshall Tract is inside the city of Austin, the Lost Creek neighborhood is in Austin's extraterritorial jurisdiction, or ETJ, until it is fully annexed by the city Dec. 15, 2015.

Martinez said property owners may request the decision on the project be postponed until after annexation.

Residents may also petition against rezoning the tract, requiring Austin City Council pass the rezoning by a supermajority vote, which would be six out of seven council members, said Jerry Rusthoven, city of Austin planning and development manager.

"A development of the size and height of Palisades West, as the developer suggested, is not compatible with our adjacent, single-family residential neighborhood," Lamm said. "A development at this location needs to be smaller-scaled and set back so that it transitions into the neighborhood."