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The United Nations building is reflected on the window of the U.S. mission to the U.N.
Improved insulation and automatic lighting - the UN's getting a green upgradeImage: (ddp images/AP Photo/Mary Altaffer

Green makeover

June 26, 2012

The energy-guzzling UN offices in New York are getting a facelift with sealed windows and improved insulation to cut energy waste. The project’s lead architect Michael Adlerstein talks about the complex renovations.


 Shortly after the United Nations was founded in 1945, a group of 50 designers hit the drawing board to come up with a blueprint for what would be the new headquarters building in New York. In the end, architects Le Corbusier and Oscar Niemeyer’s designs won out. Construction began in 1947, and 5 years and $65 million later, the 39-story sky scraper in the Turtle Bay neighborhood of Manhattan with its famous glass curtain as an outer wall was complete. Back then, green building practices were still far from many architects’ minds.  

Sixty years later in 2007, work began on a much-needed renovation of the iconic building. This time, the focus has been on on sustainability, historic preservation and security. The plan involved stripping the building down to the basics and replacing the outdated air-conditioning, lighting, wiring and plumbing. The aim is to make the building far more green and reduce its energy consumption. UN Secretary-General Ban Ki-moon has called the renovation project "our down payment to ensuring a modern, energy efficient" UN headquarters.

The nearly $2-billion renovation is nearly complete with the first UN employees set to move back into the building in August. Global Ideas sat down with the man leading the project, Michael Adlerstein. The Brooklyn-born architect talks about why UN staff will no longer be able to open their windows, why the landmark building's getting a new glass facade and why photovoltaics and wind turbines will no longer play a role. 

Michael Adlerstein
Michael Adlerstein is the project's executive director and a UN assistant secretary-generalImage: ddp images/AP Photo/Osamu Honda

Global Ideas: Mr. Adlerstein, after the renovations are complete, employees will no longer be able to open their windows. Wouldn’t it be more energy efficient to let in some cool air from the East River than to install air conditioning?

Michael Adlerstein: We had the windows closed not because of energy considerations. The windows are closed for blasts. So if there is a blast on 1st Avenue or anywhere in the vicinity, we have very very durable glass. Like a car windshield, (we have) multiple laminations that will not be damaged by a blast. It has a very hard resistance.

Security required us to close the windows which was very sad. We do feel that it was wonderful in the past when the windows were operable. The staff doesn’t know it yet. They know it intellectually but when they experience it, they will be very sad too. It was always a wonderful thing about the UN, that you could operate the windows.

It’s better for the abusers because people open their window and then they go home. Engineers always prefer a sealed building. But if you have a disciplined, organized workforce that will open the windows on a spring or fall day where the temperature is very nice outside, you could generate a lot of savings in terms of energy consumption through the intelligent use of open windows. But in most cases, people are not so disciplined.

There will be motion-sensor lights too that go off when there’s no movement.

Right. The lights are connected to both motion detectors as well as photo (light) detectors. Our building faces east and west, so when the morning sun is shining in, the lights on the east will dim because they’re not necessary and the sunlight will take care of the proper lighting level. On the west side in the afternoon, the same thing will happen. When an individual room is empty for something like 10 minutes, the lights will go off. 

 I’m just thinking about delegates working intensely on their computers, not moving at all, reading something – what happens then?

The UN General Assembly
The UN General Assembly is to get dimmed air conditioning systemsImage: dapd

 It’s not the worst thing in the world. You move your arm and the lights go on. It does remind you that we are in an energy conscious world. It is a very important thing in the UN. The UN is a very strong advocate of energy conservation. One of Secretary General Ban Ki-Moon’s major initiatives is to keep it right in front of our eyes, for the whole world.  

The secretary general tries to make sure that the UN not only speaks about energy conservation but exhibits it. Like right now we’re under this Cool-UN protocol where the temperature in the UN is three degrees warmer than normal. It will be throughout the summer. It will be 75 degrees in the office space all over the UN. During the winter, instead of being 72 which is normal, it will be 69. It will be three degrees cooler during the winter. We do try to practice being very good citizens. 

Have you had any reactions from employees? Complaints?

 When it was very hot at the end of May, we were getting many complaints from the delegates and from the staff that it was too hot. But it’s only a three degree difference. But people feel that three degree difference.

 Do those complaints have any effect on the temperature settings?

 If it turns out that someone set it wrongly and it’s 76 or 77 then we adjust it. But if the temperature is 75, that’s what we will do. We’ll keep it at 75.

 What would you say is the most outstanding green measure?

I think in architecture you can make a building less energy consumptive by making your production of heat and air conditioning more efficient or by improving your envelope. I think the UN was losing a tremendous amount of energy through its envelope. The old glass curtain wall, which is so much of the facade of the UN, is glass. Both the secretariat and all the buildings have an enormous amount of glass, and that was all 1952 glass - very thin, single-paned with leaky caulking and early aluminum design. So by installing a new curtain wall,we have improved the envelope of the building tremendously. I think that’s our most significant greening measure. We lose less air conditioning going out and we lose less heat going out.  

There were some things still in consideration, like a solar roof and there was something about wind turbines too?

Urban development in lower Mahanattan with the World Trade Center
The refurbished UN headquarters is expected to become a model for other skyscrapers around the worldImage: AP

  Originally,we were going to install photovoltaic panels on the curtain wall. We found that to be unfeasible. It doesn’t face the right angle – they would be vertical. The only way to make it feasible would be to slope it up to the sky and that would visually make it a very different building. We were considering some demonstrations. We were going to do a wind turbine demonstration which we have decided against. There is not enough wind on our site to turn the propeller. And it’s very embarrassing if you have a wind turbine that doesn’t move. The winds in New York are occasionally gusty but we are far below the recommended wind levels for a wind turbine, especially at ground level.

Even though we’re cutting our energy by 50 percent, we're a big energy consumer because we’re a conference center, and conference centers are very heavily lit for broadcast purposes. We would never be able to generate more than a small little percent, less than one percent with photovoltaics and wind energy.

Is the renovation a model for other institutions and UN countries?  

Absolutely. I think it is one of the few full restorations ever done that meet the US Leeds Gold Standard, that meet this very high level of sustainability. We are meeting a very high level of stability in greening, as well as meeting the standards of historic preservation so the UN will look the way it did in 1952.

No one has been able to find another example of a compound this big which has been totally restored with almost no new additions that are being faithfully restored and meeting a very high standard of sustainability. So we are very proud of it.

 Author: Johanna Treblin/ss
Editor: Sonia Phalnikar

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