Children's Hospital plans to move to Fitzsimons in Aurora. The building will be part of the redevelopment of the downtown site following the move. Many of the hospital buildings will be torn down and replaced with new buildings, but with the new designation, the exterior of Tammen Hall must be preserved and kept within its original appearance.

The Landmark Commission must approve any changes to the façade. John Shaw, who heads Opus Northwest's Denver regional office tells GlobeSt.com that any developer who considers developing the site will go in with the knowledge that the building cannot be razed. Shaw is advising Children's Hospital.

The eight-story building currently houses the Children's Hospital's administrative offices and clinics. The building is named for Harry and Agnes Tammen, who donated $100,000 toward the construction of Tammen Hall. Harry was the publisher of the Denver Post newspaper from 1895 to 1924.

Children's Hospital and Capital Hill United Neighborhood, better known as CHUN, submitted the application to preserve the building last February. Thelandmark application was supported by Elbra Wedgeworth, the Denver CityCouncil Woman who represents the district.