New York City Icon Goes Greener

Earlier this week, a more than $500 million building upgrade program for the Empire State Building was announced. Serving as a test case and model for energy efficiency upgrades in large, existing buildings, this project involves several environmental consulting, non-profit, design, and construction partners—including the Clinton Climate Initiative, Rocky Mountain Institute, Johnson Controls Inc., and Jones Lang LaSalle.

The program now underway at this New York City architectural icon uses a comprehensive approach that integrates multiple steps and measures to use energy more productively. With integration as a key, the program is expected to reduce energy consumption by up to 38% percent and will provide a replicable model for similar projects. Building systems work is slated to be completed by the end of 2010, with the balance of the work in tenant spaces planned for completion by the end of 2013. (Work scheduled to be complete within 18 months will result in over 50% of the projected energy savings. The balance will be an additional 36 months completed by 2013.)

Original construction of the Empire State Building was completed in 1931.
Original construction of the Empire State Building was completed in 1931.

The parties involved spent eight months in the “project definition process” during which time the team analyzed the steps to be taken in conjunction with other steps towards sustainability as part of the Empire State ReBuilding program. The process was also evaluated within the framework of the U.S. Green Building Council LEED rating system. (Internal calculations show that the Empire State Building will be able to qualify for Gold certification for LEED for Existing Buildings, and the ownership intends to pursue such certification.) Additionally, the building is expected to achieve an ENERGY STAR score of 90, placing it in the top 10% of efficiency for Class A buildings.

Jones Lang LaSalle is serving as program manager of the collaborative team under the direction of Anthony E. Malkin of Empire State Building Company to develop the first comprehensive approach to model steps for the reduction of energy consumption, and to share details of the process to create a replicable model for energy projects in buildings around the world. With an initial estimated project cost of $20 million, additional savings and redirection of expenditures originally planned in the building’s upgrade program, and additional alternative spending in tenant installations, the Empire State Building will save $4.4 million in annual energy savings costs, repay its net extra cost in about three years, and cut its overall carbon output.

An Integrated Retrofit Approach
The project partners used existing and newly created modeling, measurement, and projection tools in a repeatable process to analyze the Empire State Building and establish a full understanding of its energy use as well as its functional efficiencies and deficiencies. This provided actionable recommendations along a cost-benefit curve to increase efficiency and without harming bottom line performance.

Clay Nesler, vice president of global energy and sustainability, Johnson Controls Inc., shared with TFM the collaboration that occurred during the eight month project definition process:

We had the benefit of diverse views and expertise in energy efficiency and sustainability. The team committed early on to take an integrated design approach and to view the project from an entire systems approach, meaning not just looking for specific improvement measures such as lighting or air conditioning but at the building as a whole. In doing that we went through a very rigorous exercise of identifying every potential improvement (there were over 60) that could be accomplished through existing technology. We then computed the theoretical minimum energy that the Empire State Building could consume; if we implemented everything how little energy could the building actually consume?

Now, we knew that would not be a very economical solution, since some of the technologies, while currently available, are very expensive. So we then simulated a number of [retrofit] scenarios. For instance, we simulated insulating the windows and putting insulation behind the radiators, which reduced the cooling load. Therefore, we sized a cooling plant, which would just meet the new reduced loads and found that instead of replacing chillers or expanding them we could actually refurbish and renovate the chillers. That saved tremendous capital costs.

Next, we analyzed in two dimensions—from a financial return on investment (ROI) perspective, as well as environmental benefit through the reduction of carbon. We found that the economic optimum—the solutions which provided the best net present value over the term of the [performance] contract—actually left a lot of carbon on the table. And that it was half as deep of an energy reduction as [would be achieved by] making a slight additional [financial] investment. So we ended up with a solution that for a very nominal additional cost resulted in very deep energy efficiency—38% reduction for the building as a whole.

A total of eight improvements were identified—if we wanted maximize the ROI, we would have pursued three or four of them. However, by doing an additional four improvement measures, there was very little effect on the financial return, yet a significant impact on additional energy reduction.

The eight key initiatives being implemented are:

  1. Window Light Retrofit: Refurbishment of approximately 6,500 thermopane glass windows, using existing glass and sashes to create triple-glazed insulated panels with new components that dramatically reduce both summer heat load and winter heat loss.
  2. Radiator Insulation Retrofit: Added insulation behind radiators to reduce heat loss and more efficiently heat the building perimeter.
  3. Tenant Lighting, Daylighting, and Plug Upgrades: Introduction of improved lighting designs, daylighting controls, and plug load occupancy sensors in common areas and tenant spaces to reduce electricity costs and cooling loads.
  4. Air Handler Replacements: Replacement of air handling units with variable frequency drive fans to allow increased energy efficiency in operation while improving comfort for individual tenants.
  5. Chiller Plant Retrofit: Reuse of existing chiller shells while removing and replacing “guts” to improve chiller efficiency and controllability, including the introduction of variable frequency drives.
  6. Whole Building Control System Upgrade: Upgrade of existing building control system to optimize HVAC operation as well as provide more detailed sub-metering information.
  7. Ventilation Control Upgrade: Introduction of demand control ventilation in occupied spaces to improve air quality and reduce energy required to condition outside air.
  8. Tenant Energy Management Systems: Introduction of individualized, web-based power usage systems for each tenant to allow more efficient management of power usage.

“Not only will this project dramatically reduce the Empire State Building’s environmental impact, but now we’re able to do it in a way that provides meaningful costs savings to the building as well as its tenants,” said Raymond Quartararo, international director, Jones Lang LaSalle.

Several of the eight measures to be implemented at the Empire State Building involve tenant related improvements, but the measures themselves (as well as the integrated approach) can be used by facility professionals in owner-occupied buildings as well. Nesler noted, “The process can be applied whether for a multi-tenant or owner occupied building. In fact, those in owner-occupied buildings would probably have an easier time because they gett the benefit on both the tenant side (that being them) and well as on the building owner side. So there are less barriers with owner occupied buildings.”

Said Amory B. Lovins, chairman and chief scientist of Rocky Mountain Institute, “To make cities cleaner and more energy efficient, we urgently need a replicable model for retrofitting existing major buildings. This visionary example will help inform and inspire initiatives that can cut carbon emissions, save energy, save money, make jobs, and provide better workplaces in buildings all over the world.”

The full analysis process is available online as open source materials for public use at

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