Historic preservation easements are voluntary legal agreements, typically in the form of a deed, that protect a historic property or cultural resource by placing restrictions on the development of, or changes to it. Under the terms of the easement, the property owner grants a portion of, or interest in the property to an organization whose mission includes historic preservation. Donation of an easement to preserve a certified historic structure or historically important land area qualifies as a charitable contribution for federal income and estate tax purposes.Under the DC Uniform Conservation Easement Act of 1986, as amended in 1993 (DC Official Code Sec. 42-202.01), when a conservation easement has been registered with the District, written consent of the easement holder is required before the issuance of a construction permit for exterior work on the property or recordation of a land subdivision for its lot. Easements are registered by presenting proof of recordation to the Historic Preservation Office in the DC Office of Planning.