Awning work on buildings located in historic districts will likely be reviewed by a historic district commission (HDC). HDCs may also review grant applications and recommend approvals for facade improvement programs, where such programs are in place. Though commissions look at projects on a case-by-case basis, many have established guidelines that address general issues and local concerns relating to awnings and canopies. Often, local design guidelines are modeled upon The Secretary of the Interior's Standards and Guidelines for Rehabilitating Historic Buildings. These standards set forth principles meant to ensure that new elements are added sensitively, do not damage historic fabric, and are compatible with the historic character of the building.