Accepting donations of façade easements is one way that Cornerstones, Inc. actively participates in long-term historic preservation in Chattanooga. Façade easements insure that the historical integrity of a building's exterior and the building itself will be maintained under current and future ownership. As incentive, federal and state laws permit the donation of a façade easement to be treated as a tax-deductible gift. The value of the easement is determined by a professional appraiser retained by the property owner. Cornerstones requires that the structure be on the National Register of Historic Places and that the façade be maintained in accordance with the Secretary of the Interior's Guidelines. Cornerstones also requires payment of a nominal fee, based on the value of the easement, to offset legal, title transfer and future monitoring costs.