tenant list had largely remained constant from its opening through the end of the 20th century. As a result, the building housed several departments that had existed since the 1950s but were unrelated to the Secretariat. Newer Secretariat departments occupied space in nearby office buildings rather than in the Secretariat Building. Maintenance issues and renovation proposals Due to funding shortfalls in the 1980s, the UN diverted funding from its headquarters' maintenance fund to peacekeeping missions and other activities. The Secretariat Building's heating and cooling costs alone amounted to US$10 million a year. Because the headquarters was extraterritorial territory, the Secretariat Building was exempt from various building regulations. Furthermore, the building's machinery created electromagnetic fields, which reportedly made some employees ill. Although the General Assembly had voted to fund the installation of electromagnetic shields in the building in 1990, that money was instead used for roof repairs. By 1998, the building had become technologically dated, and UN officials considered renovating the headquarters. The Secretariat Building did not meet modern New York City building regulations: it lacked a sprinkler system, the space leaked extensively, and there were large amounts of asbestos that needed to be removed. The mechanical systems were so outdated that the UN had to manufacture its own replacement parts, and up to one quarter of the building's heat escaped through leaks in the curtain wall. The building used massive amounts of energy because, at the time of the tower's construction, the UN had not been as concerned about energy conservation. Part of one story had been vacated because of interference from electromagnetic fields. The New York Times wrote that "if the United Nations had to abide by city building regulations [...] it might well be shuttered". At the time, the UN had proposed renovating the building for $800 million, as UN officials had concluded that the long-term cost of renovations would be cheaper than doing nothing. The UN commissioned a report from engineering firm Ove Arup & Partners, which published its findings in 2000. The report recommended renovating the UN headquarters over a six-year period and adding ten stories to the Secretariat Building. Several options for renovating the UN headquarters were presented. The most expensive alternative, costing $245 million, called for the Secretariat Building to be rebuilt in several phases, requiring the relocation of one-third of the building's staff. Another option would have cost only $74 million and would