The first major renovation of the 60-year-old headquarters has been slowed by extra security measures, said New York architect Michael Adlerstein, the project's executive director and a UN assistant secretary-general.
A $2bn facelift for the United Nations headquarters
UNITED NATIONS // The whirr of saws and buzz of drills flood buildings better accustomed to the speeches of world leaders as the United Nations' headquarters in New York gets a makeover. Gone are the pneumatic tubes and the toxic asbestos.
And blast-proof panes are replacing the original windows - addressing terrorism concerns in a post-September 11 world.
The first major renovation of the 60-year-old headquarters has been slowed by extra security measures, said New York architect Michael Adlerstein, the project's executive director and a UN assistant secretary-general. The final cost will be nearly $2 billion (Dh7.34bn) - about 4 per cent over the original budget.
Terrorists have increasingly targeted UN compounds, with 12 staff members fatally injured in August by a car bomb at the compound in Abuja, Nigeria. Top envoy Sergio Vieira del Mello was among 21 people killed in a 2003 attack on the organisation's Baghdad complex.
While the changes at New York headquarters are welcome, the renovation has required more than a little diplomacy.
The UN "is far more complicated than any organisation I've worked with," acknowledged Mr Adlerstein, who also oversaw the restoration of the Statue of Liberty and Ellis Island for the US in the 1980s. "But the UN continues to function at a very high level every day while we are working around them."
Still, there have been conflicts.
Several times last year, members of the powerful Security Council asked workers to stop demolition in the basement because the banging was interrupting their meetings.
And the UN Staff Union complained early on that the modernisation project broke a promise not to begin asbestos abatement until all employees had been moved. At the time, Secretary-General Ban Ki-moon said steps were being taken to protect workers' health.
UN employees also charge that they have not been consulted about the construction, and oppose plans to eliminate most private offices in favour of shared open working spaces.
"I'm sure it's going to look nice, but I'm not sure if the working conditions will be ideal," said union president Barbara Tavora-Jainchill. "It all goes back to the fact that we are not being fully informed."
About 3,000 UN staffers once based on the campus along the East River now work in temporary office space scattered around Manhattan. Another 2,000 remain on the 6.8-hectare site, including Mr Ban and other senior officials, who work in a temporary building constructed just north of the main one.
Inaugurating the temporary building two years ago, Mr Ban called the renovation project "our down payment to ensuring a modern, energy efficient" UN headquarters.
Mr Adlerstein said all work should be completed before the UN General Assembly's annual ministerial meeting in September 2014.
The conference building housing the Security Council is expected to be the first part of the project to partially reopen, with the council returning to its quarters early next year. The building was fortified last year with an extra $100 million from the United States.
The United States itself has strengthened its new 26-floor mission in the shadow of UN headquarters with reinforced concrete and steel walls.
Planners have decided to respect the UN compound's original architecture of the 1950s, dominated by the Secretariat building, a rectangle of white stone and green glass that 20th century critic and historian Lewis Mumford described as "fairy-like in its cold austerity".
The streamlined exterior became part of popular American culture when it appeared in Alfred Hitchcock's 1959 spy thriller North by Northwest. Because the UN banned filming on the property, a movie camera that Hitchcock hid inside a parked van captured actor Cary Grant entering the location.
Inside, sofas and Barcelona chairs made of Naugahyde are being retained, as well as signs using Neutra, a modernist typeface popular in the early 1950s.
The design team included international luminaries Oscar Niemeyer of Brazil, who later designed key public buildings for his country's capital of Brasilia, and Le Corbusier of Switzerland, a modern architecture pioneer. The principal architect was American Wallace K Harrison, who envisioned the project as a "workshop for peace".
Finished in 1950, two years before the entire complex was done, the main 39-floor building was among the world's first skyscrapers largely made of glass and boasted 5,200 windows that could be opened.
The new windows, for security reasons, are now sealed closed.