Allied Insurance is building an urban park on a plot of land a block west of its new downtown office building, but executives haven’t yet determined whether it will be made available to the public.

Already, construction crews have installed curbs and sidewalks at the park, which is located at the corner of 12th and Locust streets. Workers have been using earthmoving equipment to landscape the terrain. Allied spokesman Rick Phillips said the company plans to plant a row of trees around the edge of the block and that “the middle part will be green,” meaning that sod will be laid and grass seed planted.

Allied purchased the block in 2000 at the same time it bought land for its 500,000-square-foot building at 11th and Locust streets. For the past two years, the park site has mostly been used as a staging area for the equipment that was used to construct the office tower.

For the city, Allied’s decision to turn the parcel into a park adds another element to the growing Gateway West project, which seeks to redevelop and improve elements of the western entrance to downtown. Allied plans to use the park as a place for its regional offices to stage events for employees, Phillips said. Before the company decides whether to open the park to outside groups and the public, Allied executives have to examine liability issues, he said. Those decisions should be made by spring, he said.

The land was originally purchased to provide room for future expansion, Phillips said. Allied employs about 1,600 people at 1100 Locust St. and another 600 at another building it owns at 701 Fifth Ave. Allied has room to add another structure at 1100 Locust because the current building occupies about two-thirds of the block. The company continues to add employees.  How quickly the project takes shape now will largely be determined by the weather, Phillips said.