Smarter Business: Case Studies

Window processing site

photo: Serious Energy

Challenge

Inefficient and improperly sealed windows in older buildings can add a costly premium to energy bills -- as much as 30 percent higher than can be achieved with triple-paned, high-efficiency windows. This wasted energy from air conditioning and heating also results in needlessly higher emissions of heat-trapping pollutants.

In 2009, the Empire State Building possessed a total of 6,514 double-paned windows with no energy-efficiency features Empire State Realty Trust, the owner of the Empire State Building (ESB), is in the process of making the landmark building a model for large-scale, cost-effective building retrofits, with a goal of reducing building-wide energy consumption by a projected 38 percent by 2012. Upgrading the ESB's older windows to super-efficient new windows accounts for a full 5 percent of this energy reduction. The costs of replacing the windows with brand new window units, however, would have added approximately $20 million to the retrofit price tag as well as increased construction waste, packaging waste, and transportation pollutant emissions. So Empire State Realty Trust partnered with two firms to come up with a cost-efficient and material-efficient alternative.


Strategy

Empire State Realty Trust's partners Johnson Controls and Jones Lang LaSalle, which were in charge of the development and implementation of this project, devised a unique solution: rebuild the windows onsite, reusing the existing glass, sash and trim and adding a barrier of low-emissivity (low-E) film to improve insulating R-values from their current level of 2.0 to up to 7.0 at a cost of only $4.5 million, $15.5 million less than the projected cost of new windows.

To avoid transportation costs and emissions associated with moving the 6,514 window units to an offsite location, Serious Energy and Kilroy Metal Products were contracted to rebuild the windows at an on-site processing area. All aspects of the upgrade could then be handled inside the ESB, with the most disruptive steps -- such as removing windows from their frames -- occurring after hours.

A workspace on the fifth floor was selected because it offered easy access for contractors and equipment brought in from street level and had fewer nearby tenants. To reduce noise even more, Serious Energy added soundproof drywall around the work area.

Triple-paned windows provide much higher insulating value, but instead of adding a third pane of glass which would boost materials use and weight on the building envelope, contractors inserted a suspended low-emissivity film between the two reused panes.

After kilning the window units to shrink the film in place and ensure its total transparency, workers injected an inert mix of krypton/argon gases to provide more insulation. The window units were then put back in the original sashes and mounted in the frames from which they were taken.

Because the North side receives no direct sunlight, the glass on this side of building was insulated to R-5 to allow some warmth during the summer. The ESB's South, East and West sides, however, were insulated to R-7 to tamp down the heat from direct sunlight throughout the summer. Work was completed during the period from April to September 2010.

On-site processing of ESB's 6,514 windows provided cost savings of more than $15 million over the purchase and installation of similarly efficient new windows with less disruption to tenants and much less waste and energy consumption. Through reductions in use of air conditioning and heating, the windows should provide CO2 emissions savings of 105,000 metric tons in the next 15 years.

Furthermore, the temporary processing space established within the ESB demonstrates the economic benefits and waste/emissions reductions that may be achieved by housing elements of retrofit operations onsite.

Care must be taken, however, to avoid disrupting tenants and degrading the quality of the business environment during business hours. It's essential to communicate with tenants to ensure they are aware of increased activity in the building and address any concerns, notes Dana Schneider, Sustainability Services Market Lead at Jones Lang LaSalle.


Results

On-site processing of ESB's 6,514 windows provided cost savings of more than $15 million over the purchase and installation of similarly efficient new windows with less disruption to tenants and much less waste and energy consumption. Through reductions in use of air conditioning and heating, the windows should provide CO2 emissions savings of 105,000 metric tons in the next 15 years.

Furthermore, the temporary processing space established within the ESB demonstrates the economic benefits and waste/emissions reductions that may be achieved by housing elements of retrofit operations onsite.


About

Empire State Realty Trust
Empire State Realty Trust, Inc. (NYSE: ESRT), a leading real estate investment trust (REIT), owns, manages, operates, acquires and repositions office and retail properties in Manhattan and the greater New York metropolitan area, including the Empire State Building, the world's most famous office building. Headquartered in New York, New York, the Company's office and retail portfolio covers 8.4 million rentable square feet, as of December 31, 2013, consisting of 7.7 million rentable square feet in 12 office properties, including seven in Manhattan, three in Fairfield County, Connecticut and two in Westchester County, New York; and approximately 623,000 rentable square feet in the retail portfolio. The Company also owns land at the Stamford, Connecticut Transportation Center that supports the development of an approximately 380,000 rentable square foot office building and garage and has an option to acquire two additional Manhattan office properties encompassing approximately 1.5 million rentable square feet of office space and over 150,000 rentable square feet of retail space at the base of the buildings.

Serious Energy
Serious Energy provides energy software services and advanced building products to improve the energy performance and comfort of commercial and residential spaces. With six manufacturing plants and a software development team, the company's products have been installed in over 70,000 projects worldwide.

Johnson Controls Inc.
Johnson Controls is a global diversified technology and industrial leader providing products, services and solutions to optimize energy and operational efficiencies of buildings; automotive batteries; and interior systems for automobiles. With 1,300 locations worldwide and 142,000 employees, Johnson Control achieved global sales of $34.3 billion in the 2010 fiscal year.

Jones Lang LaSalle
Jones Lang LaSalle is a financial and professional services firm specializing in real estate services and investment management. The company has more than 40,300 employees in 60 countries and reported a net income of $154 million in 2010.

Kilroy Metal Products
Kilroy Metal Products retrofits windows in offices and apartment buildings in the New York metropolitan area.


Resources

Johnson Controls

Kilroy Metal Products

Jones Lang Lasalle

Empire State Realty Trust

Serious Energy ESB site

last revised 4/23/2014

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