by By Paul Rode — As leaders of New York City take steps to reduce the city’s carbon emissions by 30 percent by 2030, it’s only fitting that a world famous landmark—the Empire State Building—be part of the solution.
A comprehensive, green retrofit of the 102-story Empire State Building, which was erected as the world’s tallest building in 1930, will reduce its energy consumption by as much as 38 percent when completed. By comparison, retrofits typically reduce energy use by 10 to 20 percent. The initiative is an innovative collaboration to develop a new approach to bringing large-scale energy efficiency retrofits to existing buildings. The project will also demonstrate that a commercially attractive retrofit and operations program can lead to significant energy savings and greenhouse gas emissions reductions.
The planning process for the Empire State Building program has been the key to its success in becoming a leader in sustainability. From assessment, quantification and documentation of the costs and benefits, the process is expected to serve as a model for other building owners and facility managers to follow in their own green projects.
The greening of existing buildings: why now?
The environmental focus on buildings has intensified with rising energy costs and widespread interest in reducing carbon emissions. In fact, the buildings in New York City create 65 to 70 percent of the city’s entire carbon footprint. Constructing new green buildings is critical, but the problem of carbon emissions will not be mitigated without addressing the energy efficiency of existing buildings.
However, owners of existing office buildings worldwide are still working to improve in the areas of energy and sustainability. This is because it is often difficult for building owners to financially justify expensive retrofit projects.
The owners of the Empire State Building are an exception to the rule. As one of the world’s most famous office buildings, the Empire State Building draws between 3.5 million and 4 million visitors each year to its 86th floor observatory. Its 2.8 million square feet of leasable office space holds a range of large and small tenants—drawn by the building’s prestige, its skyline views and its convenient location in Manhattan.
The changes to the Empire State Building are anticipated to enhance the building’s long-term value based on the opportunity for higher occupancy and rents over time. Green buildings have a competitive edge in attracting companies interested in reducing their own carbon footprints, as well as providing work environments that promote the health and well-being of employees. Eventually buildings could also be affected directly or indirectly by sustainability-inspired regulatory changes.
Developing a solid business case for financing improvements in cash flow from reduced energy costs requires a robust analytical process. The Empire State Building team worked to establish a format that all properties could use as a model.
A collaborative effort
The Empire State Building project involves a coalition of leading organizations in the fields of sustainability, energy services, real estate, environmental design and climate change. Johnson Controls, Inc., Jones Lang LaSalle and the Rocky Mountain Institute came together through the convening power and advisory support of the Clinton Climate Initiative, under the leadership of the Empire State Building Company LLC.
The project team’s five key players have collaborated to develop an economically-viable combination of innovative approaches to infrastructure projects, design standards, tenant energy management, property management, and leasing and marketing initiatives that will be a leading example for the industry.
A new evaluation process
The project partners used existing and newly created modeling, measurement and projection tools to analyze the Empire State Building. By examining the building’s energy use and its functional efficiencies and inefficiencies, the team developed recommendations to increase energy efficiency without harming bottom line performance.
During an eight-month design phase in 2008, the team rigorously considered more than 60 optional activities from multiple sources that would provide the optimal balance of financial and environmental return on investment (ROI). Building systems, staff operations, electric and gas utility measurements were some of the elements examined.
A detailed, three-month budget and scope review with the building owner resulted in the final program approval for implementation. Eight economically-viable projects were identified, including building-wide renovations, electrical and ventilation system upgrades and tenant space overhauls. These projects will provide a significant ROI, both environmentally and financially.
The initiative—known as Leadership in American Progress in Sustainability—reflects the importance of creating a set of protocols that other owners could learn from and use.
The analysis was divided into four parts, an inventory and programming phase, a design development phase, a design documentation phase and a final documentation phase. These four phases were completed in seven months.
Phase I: inventory and programming
In the first phase, team members conducted reviews of the building’s mechanical systems and equipment, calculated tenant energy usage, and developed a baseline energy benchmark report and a preliminary system for measuring energy efficiency. A gap analysis was conducted to determine which green building criteria the building was already meeting and which could be achieved feasibly. A plan was then developed for the creation of prebuilt green offices to serve tenants with immediate needs. Lastly, a separate cross-functional workshop was conducted to look specifically at lighting strategies.
The central initiative of Phase I was integrating the initiative’s goals with those of a separate capital projects team already in place. The Empire State Building had previously embarked on a capital program that included restoring and upgrading common areas and the popular observation decks.
Value engineering the existing capital projects would help avoid having to make changes later. Integration of the capital team and the sustainability team allowed the latter to pursue a whole-building approach—modifying current strategies to meet higher sustainability standards.
Phase II: design and development
In Phase II, the possible building resolutions were narrowed down to a manageable number of potential solutions. This helped to create order out of complexity. Also in this phase, Johnson Controls presented a baseline energy report on energy usage including a month-by-month breakdown of electricity and steam usage. The report detailed energy expended toward lighting, ventilation, broadcast towers, main plant cooling, tenant sub-metering and other uses.
The team determined and reviewed the minimum energy usage to address occupant comfort requirements, system design characteristics, technology, controls and operating schedules. By raising the cooling set-point, enhancing the envelope and ventilation, reducing internal gains and improving cooling efficiency, it was estimated that the building could reduce energy usage significantly.
Other challenges were indentified at this point. Bold concepts needed to be incorporated within conventional budget limitations. Additionally, tenants would need incentive to follow the model’s guidelines. More efficient heating, ventilation and air conditioning (HVAC) systems needed to be designed and all parties would have to commit to average load reduction and lifecycle costs rather than merely efficient system design.
Finally, the team recommended changes for sustainable tenant prebuilt spaces. These included reducing the number of interior wall enclosures to enhance natural light and views, selecting interior finishes to support sustainable goals and using task lighting to complement higher efficiency overhead lighting.
Phase III: design documentation
Phase III of the analytical process centered on two goals. The team first developed a report assessing the tenant energy usage and the impact of prebuilt spaces. Secondly, they wanted to develop and refine the eQuest Energy Model, a user-friendly, computer-based energy modeling program.
The team worked to find ways that the facility management staff could easily monitor energy usage of each floor and each tenant on that floor. A computer dashboard would be implemented to automatically translate numeric data into visual data, such as charts and graphs, so that managers could more easily spot trends and act on them.
The second piece was the development of the eQuest Energy Model. Drawing on a program developed by the U.S. Department of Energy, the model is designed to be used for cost/benefit analysis for future improvements, modifications and operational changes for buildings. The energy consumption baseline is compared to various facility improvement measures in order to calculate energy savings of these measures on a stand-alone basis and in combinations with other measures.
By creating a matrix that analyzed the costs and financial benefits of facility improvements and other potential green strategies, the team created a comprehensive sustainability scorecard. This scorecard demonstrated how different strategies would affect project cost and building performance.
Phase IV: final documentation
In the final phase of planning, the team created a master plan for integrated sustainability within the Empire State Building. All the data from the standards and measurement tools was synthesized to create the final project recommendations.
The results pointed to a clear solution: pursue a program that would reduce energy use and greenhouse gas emissions by up to 38 percent, resulting in 105,000 fewer metric tons of carbon dioxide emitted over the next 15 years.
In addition to recommendations on which strategies to follow, the team examined the length of time needed for implementation. This was a significant consideration because a key metric of each strategy was the payback period for capital invested.
The well-researched, planned retrofit uses the right steps in the right order for whole-systems optimization. The project reduces energy demand by addressing the building envelope (such as the window and radiator projects) and through tenant energy use (such as the tenant space design and energy management). This takes the retrofit beyond the traditional HVAC equipment replacements.
The Empire State Building’s owners agreed to the following eight retrofit projects:
- 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.
- Radiator insulation retrofit — Added insulation behind radiators to reduce heat loss and more efficiently heat the building perimeter.
- 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.
- Air handler replacements — Replacement of air handling units with variable frequency drive fans, allowing increased energy efficiency in operation while improving comfort for individual tenants.
- Chiller plant retrofit — Reuse of existing chiller shells while removing and replacing the guts to improve chiller efficiency and controllability, including the introduction of variable frequency drives.
- Whole-building control system upgrade — Upgrade of the existing building control system to optimize HVAC operation as well as provide more detailed sub-metering information.
- Ventilation control upgrade — Introduction of demand control ventilation in occupied spaces to improve air quality and reduce energy required to condition outside air.
- Tenant energy management systems — Introduction of individualized, Web-based power usage systems for each tenant, allowing allow more efficient management of power usage.
The initial US$20 million investment will result in US$4.4 million in annual energy savings. In fact, energy and operation savings are funding much of the project.
A portion of the reduced energy use will come from the building’s tenants, whose comfort will also be improved through improved design and energy awareness. Ultimately, the project will improve the building’s marketability and serve as a model for other multi-tenant building retrofits.
A model worth repeating
The partners successfully created the replicable model that the owners of the Empire State Building set forth to establish, delivering a commercially attractive sustainability retrofit. The thorough and collaborative process resulted in a strong consensus backed by transparent information.
The analytical process is the first step toward achieving an optimal energy and sustainability profile at the Empire State Building, but it was of critical importance to the ultimate success of the program. The strategies selected from this process will not only have a significant impact on the building’s carbon footprint but will open doors to additional avenues for financing.
The Empire State Building is just one of the thousands of commercial buildings that must undergo some form of energy and sustainability retrofit in the next several years if we, as a society, are committed to reducing the impact of buildings on the environment.
About the author
Paul Rode is the Johnson Controls Inc. project executive for the Empire State Building retrofit in New York City. He serves on the Green Codes Task Force for the City of New York. Rode may be contacted at paul.rode@jci.com.