The Zoning Commission may from time to time amend the regulations and the maps, but before doing so a public hearing must be held, and at least 30 days’ notice of the time and place of the hearing must be published at least once in a daily newspaper in the District of Columbia, giving full information concerning the proposed amendment. A favorable vote of not less than a full majority of the members is necessary for the adoption of an amendment. The Zoning Commission consists of five members, namely, the three Commissioners of the District of Columbia, the Director of the National Park Service, and the Architect of the Capitol. The act of 1938 provides for a Zoning Advisory Council, to which suggested amendments to the regulations are submitted for consideration and recommendation. The act also provides for a Board of Zoning Adjustment, which shall have the power to hear and decide appeals where it is alleged a hardship will be imposed by carrying out and enforcing any regulation adopted under the Zoning Act, and to hear and decide on complaints regarding zoning, as also requests for special exceptions or map interpretations. In exercising its powers, “the Board of Adjustments may, in conformity with the provisions of this act, reverse or affirm, wholly or partly, or may modify the order, requirement, decision, determination, or refusal appealed from or may make such order as may be necessary to carry out its decision or authorization, and to that end shall have all the powers of the officer or body from whom the appeal is taken.” The concurring vote of not less than a full majority of the members of the Board is necessary for any decision or order. HEIGHT OF BUILDINGS RESTRICTED BY THE CAPITOL DOME The preeminence of the Dome of the Capitol has dominated the height of both public and private buildings. The 110-foot-height limit is found in a small section of the center of the downtown business district. On streets 110 feet wide in the 110-foot-height district, 130 feet is allowed under set-back provisions, and this maximum height cannot be exceeded by buildings (except spires, penthouses, or other excrescences) erected under the zoning regulations. Before 1929 but few buildings exceeded this height. The act of 1910 limited the height of buildings to front or abut Union Station Plaza to 80 feet. [Illustration: REGIONAL PLAN OF WASHINGTON AND ENVIRONS] CHAPTER XVII THE NATIONAL CAPITAL PARK AND PLANNING COMMISSION