central role in the governance of New Zealand". Blyss Wagstaff of Heritage New Zealand called it "one of the most recognisable buildings in the country". Heritage New Zealand assigned the highest rating for a historic place, Category I, to the building. The original application for the heritage designation was made by Lockwood Smith, a former Speaker of the House of Representatives. The heritage registration with the list number 9629 became effective on . The tunnel to Bowen House is specifically excluded from the heritage registration. Facts and figures The building is ten storeys () high and has four floors below ground. The entrance foyer's core is decorated with marble floors, stainless steel mesh wall panels, and a translucent glass ceiling. The Beehive's brown roof is made from of hand-welted and seamed copper. It has developed a naturally weathered appearance. A tunnel runs under Bowen Street from The Beehive to parliamentary offices in Bowen House. The Beehive is extensively decorated with New Zealand art. On the inner wall of the Banquet Hall is a mural by John Drawbridge long and high portraying the atmosphere and sky of New Zealand. The Beehive's circular footprint (see rotunda) is generally considered an elegant and distinctive design feature. However it is also quite impractical, as many of its rooms are wedge-shaped, curved or asymmetrical. An extension has been built out the front to allow for a new security entrance. A new, bomb-proof mail delivery room has already been built at the rear of the building. The Beehive has, since 1992, featured as part of the design of the New Zealand twenty-dollar note. A survey commissioned by the Reserve Bank of New Zealand found that the Beehive is "a New Zealand icon and as such is readily recognisable". Offices and facilities The top floor is occupied by the Cabinet room, with the prime minister's offices directly beneath on the ninth floor (and part of the eighth). The upper portion of the Beehive also contains the offices of other ministers; senior ministers are situated at proximity to the prime minister's office according to their ranking in Cabinet. The seniority of a minister is reflected in how far up the building they are. Some ministers, especially junior ministers, are instead based in Bowen House. Other facilities within the building include function rooms and a banqueting hall on the first floor of the Beehive, which is the largest function