Empire State Building Retrofit
General Information
- Building Name: Empire State Building
- Building Location:
- City: New York
- State: New York
- Country: USA
- Project Size (ft², m²): 2.1 million square feet
- Building Type(s): Historic skyscraper office building
- Project Type: Historic retrofit
- Total Building Costs: $20M
- Owner: Anthony Malkin
- Client: Empire State Building Company
- Services: Peer reviewer and design partner
- Building Architect/Project Team:Rocky Mountain Institute, Jones Lang LaSalle, Clinton Climate Initiative, Johnson Controls
- Project Contact Person: Carolyn Fluhrer, Rocky Mountain Institute
Description
The Empire State Building Retrofit modernizes the iconic skyscraper, allowing the building owner to offer state-of-the-art office amenities in a historic building while greatly reducing both energy use and carbon emissions. The retrofit is now is serving as a model and template for other multi-tenant, multi-story retrofits that promote sustainability.
The project is a model of integrated design and whole-system thinking. On the advice of the design team, the contractor is removing the building's 6,514 windows' sashes and glass, cleaning the glass, and adding a low emissivity (low-E) film and gas mixture between the reused panes. This project prompted cascading energy savings; as a result of the lower SHGC and increased r-value of the windows, the chiller plant could be retrofit and downsized instead of replaced and upsized, saving considerable capital and operating costs.
In addition to upgrading the windows, the team recommended upgrading or replacing major building systems and identified seven more economically viable projects that provide an overall 3-year payback and a 38% energy use reduction. The recommended measures also reduce cooling load requirements by 33 percent (1,600 tons) and peak electrical demand by 3.5 megawatts, benefitting both the building and the utility. The measures also improve indoor environmental quality for tenants by way of enhanced thermal comfort from better windows, radiative barriers, and superior controls; they improve indoor air quality through tenant demand-controlled ventilation; and they create better lighting conditions that coordinate ambient and task lighting. The measures include projects related to:
- Window Retrofit
- Direct Digital Controls (DDC)
- Tenant Lighting, Daylighting, and Plugs
- Variable Air Volume (VAV) Air-Handling Units (AHUs)
- Retrofit Chiller Plant
- Tenant Energy Management Program
- Radiative Barrier, and
- Tenant Demand Control Ventilation (DCV)
Project completion date: 12/2013
Overall Project Goal/Philosophy
One of the major goals of the Empire State Building retrofit was to ensure the process to achieve comprehensive energy savings would be transparent and replicable for other commercial properties.
Cost-Effective Goal
Recommendations capitalized on the pre-existing capital improvement plan.
Historic Preservation Goal
Providing state of the art office building amenities in a historic building. The building and its street floor interior are designated landmarks of the New York City Landmarks Preservation Commission and it was designated as a National Historic Landmark in 1986.
Process
RMI's Eight (or so) Steps to a Deep Retrofit
In the course of RMI's work retrofitting the Empire State Building and other projects, RMI created a deep process for retrofitting existing buildings. The process, in comparison to atypical retrofit process, appears in the chart below.
| Typical Retrofit | Deep Retrofit |
|---|---|
|
|
Information and Tools
In close collaboration with RMI, JCI ran energy analyses using DOE-2.2 (eQUEST interface), a building energy simulation tool that allows for the comparative analysis of building designs and technologies. By inputting weather files, building geometry, material properties, equipment schedules, and system components, the program computes building loads and outputs building energy use.
Once preliminary energy savings estimates for individual measures were provided, the team turned to the financial model (developed by RMI specifically for this project) to determine how to create packages of measures that maximized greenhouse gas savings while providing reasonable economic benefits. Iterations between these models helped the ESB team make final recommendations to ESB ownership regarding specific short-term and long-term projects and programs they can implement.
Products and Systems
The project is a model of integrated design and whole-system thinking. On the advice of the design team, the contractor is removing the building's 6,514 windows' sashes and glass, cleaning the glass, and adding a low emissivity (low-E) film and gas mixture between the reused panes. This project prompted cascading energy savings; as a result of the lower SHGC and increased r-value of the windows, the chiller plant could be retrofit and downsized instead of replaced and upsized, saving considerable capital and operating costs.
In addition to upgrading the windows, the team recommended upgrading or replacing major building systems and identified seven more economically viable projects that provide an overall 3-year payback and a 38% energy use reduction. The recommended measures also reduce cooling load requirements by 33 percent (1,600 tons) and peak electrical demand by 3.5 megawatts, benefitting both the building and the utility.
Energy Issues
Energy Use Description
While retrofits typically reduce energy consumption by 10-20 percent, RMI proposed an integrated approach to realize savings of almost 40 percent.
Indoor Environment
Indoor Environment Approach
The team designed a space on the 42nd floor of the Empire State Building to use in marketing space to prospective tenants. Key design features include a low-pressure drop HVAC system, and indirect layered lighting system (ambient-task-accent lighting), new high performance glazing, light sleeves and blinds, and local, high-recycled content construction materials. The retrofit overall will result in increased thermal comfort for tenants from better windows, radiative barriers, and superior controls; they improve indoor air quality through demand controlled ventilation; and they create better lighting conditions that coordinate ambient and task lighting.
Project Results
A. Lessons Learned
Developing robust solutions requires dynamic, multi-year models and collaborative efforts. The implementation team would need to anticipate and address changes in tenant profiles, vacancy rates and technology as well as building renovations and the possibility of tenant disruptions. Maintaining flexibility and collaboration in the team would ensure the success of the program.
Delivering the maximum cost-effective CO2 reduction requires a whole-system and life-cycle view. A proactive, long-term plan is required to maximize CO2 and financial benefits. One reason is that the most cost-effective efficiency upgrades would have to be linked to major capital upgrade projects. In addition, the team's assessment showed that rapid acceleration of efficiency implementation produced significant extra cost without providing a similarly large benefit.
The results reinforce the need to address the natural tension between business value and CO2 reductions. The scenario that maximized business value would avoid more than half of the CO2 reduction opportunity. Even the recommended program merely balanced cost and benefit at a point where the greatest benefit could be achieved for the lowest cost, rather than pursuing every viable CO2 reduction measure without regard to cost. In order to make the business case, perceived needs and industry norms needed to align with energy-efficiency levers.
Rapid dissemination and adoption of the results requires development of an efficient process to reduce time and costs. To drive speed and effectiveness, the team recommended development and use of tools to diagnose and categorize a portfolio of buildings; to rapidly develop a "first cut" answer; and to navigate through the iterative process between energy and financial modeling at the project level. Empire State Building Company accepted the team's proposed solution in its entirety (final project scope TBD), allowing the team to move forward immediately on implementation. The thorough and collaborative process had resulted in a strong consensus backed by transparent information. Tools were developed to measure and give feedback on building-wide and tenant improvements. The team now had a mandate and a plan to move forward swiftly and with confidence that the framework for decisions would continue to yield positive results, ultimately serving the goals of the Empire State Building owners and tenants as well as overall environmental goals.
A Look Forward
The analytical process was merely 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 cost-effective avenues of financing the project.
The Empire State Building is just one drop in an ocean of commercial buildings that must undergo some form of rational 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. It is hoped that by making available documentation and information such as this report, the Empire State Building sustainability team can clear a path for thousands of other buildings to follow.
B. Publishing
- Empire State Building: Leadership in American Progress in Sustainability
- Retrofitting America's Favorite Skyscraper, Solutions Journal, Spring 2009