Through its Plan for Transformation, CHA had been trying to remake public housing by knocking down high-rises that concentrated poor and lower-income residents in one place. The agency was supposed to replace those buildings with mixed-income apartment complexes. But the agency was criticized for moving too slow to rebuild and displacing thousands of residents from their communities in the process. The Plan for Transformation is nearly 20 years old and CHA has still not delivered all the promised units. It also failed to return all the residents back to their home communities.