A mixed-use building under construction in the District at Prairie Trail in Ankeny will include a rooftop patio, a feature not found in similar buildings in the development.

“We think it’s a feature that will be used a lot,” said Ashley Johnson, marketing director for D.R.A. Properties LC, a real estate development company founded by Dennis Albaugh. The rooftop patio is “unlike anything we’ve ever built before.”

Prairie Trail, spread over more than 1,000 acres around the intersection of Southwest State Street and Southwest Magazine Road, began in 2008.

The development’s newest mixed-use building will include retail on the ground level and two floors of office space. It is the fifth mixed-use building constructed by D.R.A. Properties in Prairie Trail. The other buildings are two-story, Johnson said.

“We decided to add a second level of office because the other buildings have leased out so well,” Johnson said of the $12 million project. “Leasing in the District has been overwhelming, especially the past year or so.” Prairie Trail, which got off to a slow start because of the 2008 recession, is “really becoming that destination we always imagined it to be.”

Several companies have moved their offices to Prairie Trail in an effort to attract workers, Johnson said. Companies “are able to provide their workers with amenities that they aren’t having to pay for in their own square footage.”

The amenities include fitness centers, coffee shops, restaurants, bars, outdoor gathering places, a library and trails.

Construction of the building is expected to be completed by early 2021.