Step 1: Transforming the Empire State Building

Typically, when large buildings undertake retrofits, they deploy the "silo" process: they will pick one or two systems to invest in for energy efficiency. The Empire State Building shows the enhanced benefits of making integrated changes involving numerous building systems. By planning and taking the right steps in the right order to make individual upgrades that interact with others, we create a much greater overall result.

The right steps in the right order: Why upgrade your heating and cooling systems before you've addressed inefficient windows and walls that let heating and cooling just seep out through the building's exterior? As an example, we dramatically improved the efficiency of the building's exterior by refurbishing our existing windows on-site and installing insulation, which then allowed us to realize even greater savings in other areas.

As part of our $550 million Empire State ReBuilding program, the building's 4 electric chillers were due to be replaced with larger units. As a result of the improvements we made to the windows and walls, we dramatically reduced the building's overall demand for heating and cooling, meaning that we could retrofit the existing chillers instead of replacing them with new ones, saving over $17 million! And we did all the work on-site, creating local, green jobs.

Retrofit Icon
90% of existing buildings will still be here in 25 years. Tearing them down and starting over is not an option: it creates tremendous waste and destroys architectural and historical icons.
Retrofit Advantages
  • Reuses materials instead of sending them to a landfill
  • Saves money by not replacing existing systems that still have life in them
  • Reduces carbon emissions by not manufacturing and transporting new materials
Window Refubishment
Window Refurbishment
Energy and money were literally flying out of the Empire State Building's double-paned windows: heat was seeping out of the windows in the winter (and cool air in the summer). Replacing the windows would have been extremely costly, and would have created a mountain of wasted materials.   The Empire State Building team devised a program to refurbish each of the 6,514 windows in a custom on-site processing center, reusing more than 96% of existing window glass and making the windows up to 4 times more efficient at keeping heat and air conditioning inside.
Refurbishment Process
Refubishment Process 1 Refubishment Process 2 Refubishment Process 3 Refubishment Process 4 Refubishment Process 5
Windows are brought to the Processing Center on the 5th floor, saving money and reducing carbon emissions by not transporting them off-site. They are disassembled and cleaned in a 3-step process to ensure no dust or dirt will be sealed inside. A spacer is inserted, and a layer of heat reflective film is installed between the panes of glass. Windows are filled with an insulating mixture of gases: the exact ratio of krypton and argon gasses varies based on where the windows are on the building and their level of sun exposure. The work crew processes 50-75 windows per day, so the work in tenant spaces is performed literally overnight with no disruption or construction debris. Refurbishment makes the windows up to 4 times more efficient, rendering them nearly as effective as triple paned windows at a fraction of the price (r-factor increase from 2 to 8), and will add an additional 25 years to their life.
Insulated Radiative Barriers
Insulated Radiative Barriers
Insulated Radiative Barriers

Beneath each of the 6,514 windows are 6,514 radiators. Like virtually every building with perimeter heating/cooling, no insulation was ever specified or installed between the radiators and the masonry walls behind them. When the radiators were on, much of the heat they generated was literally heating the outside of the building.

Not all energy efficient solutions are high-tech. We also removed each radiator and installed an inexpensive insulating barrier that reflects 24% more heat back into the building. Not only is heat reflected into the tenant occupied spaces, in summer cool air does not seep through the masonry walls, thereby reducing the cooling load.

Additionally, every radiator is connected to a digital control system to make sure that steam consumption is only as much as is needed, allowing us to monitor the performance and function of every piece of equipment.