The Project at a GlanceDownload
|Global Brands Group
|Empire State Realty Trust
|350 Fifth Avenue, New York, NY
|137,400 square feet
In January 2011, Global Brands Group Holding Ltd. —a worldwide leader in global retail and apparel—leased 137,000 square feet on floors 7,8, and 9 in the Empire State Building. Global Brands Group (known as Li & Fung USA when the lease was signed) was aware of the major capital improvement program and retrofit that the building had recently undergone and knew that the building owner would be supportive of its own goals to reduce operational costs, increase energy efficiency, and implement sustainability best practices into its new space.
At the recommendation of the building owner, Global Brands Group chose to follow the Tenant Energy Optimization process to help achieve its sustainability and financial goals. The process is a proven, replicable approach that integrates energy efficiency into tenant space design and construction and delivers excellent financial returns through energy conservation. The process would also help Global Brands Group meet certain lease conditions required by Empire State Realty Trust related to reducing lighting power density; optimizing the heating, ventilating, and air conditioning (HVAC) system; and reducing plug loads.
|Floors 7 to 9 buildout||Projected results*|
|Annual electricity reduction||168,820 kWh1.2 kWh/SFkWh / kWh/SF|
|Total electricity savings over lease term||2.5 GWh18.2 kWh/SFGWh / kWh/SF|
|Adjusted incremental implementation cost||$134,030 total$0.98/SFTotal / SF|
|Total electricity cost savings over lease term||$438,090 total$3.19/SFTotal / SF|
|NPV of project investment||$169,118 total$1.23/SFTotal / SF|
|ROI over lease term||126%|
|Payback period (with incentives)||4.6 years|
Executing the Process
Design and Construction
Global Brands Group’s buildout project was one of the first applications of the Tenant Energy Optimization process. Empire State Realty Trust helped Global Brands Group assemble a project team led by experienced private sector consultants who were familiar with the Empire State Building retrofit. This helped establish a streamlined and more effective collaboration.
The project team outlined goals for the project and developed a list of candidate Energy Performance Measures (EPMs) that would help achieve those goals. EPMs are technologies and systems that aim to reduce energy use through efficiency and conservation. They are also frequently referred to as energy conservation measures (ECMs).
Important factors Global Brands Group wanted to consider during the design included the following:
- Measures that could be easily replicated and implemented at other office locations;
- Flexibility to allow for retail showroom space as well as office space for creative designers and staff; and
- IT data speed that would provide the ability to conduct business with international offices and ensure smooth operation of e-commerce.
With these objectives in mind, the team used energy performance modeling, incremental costing information, and cost savings projections to choose a package of EPMs that would meet the energy and financial goals of the company. The EPMs that were implemented in Global Brand Group’s space on floors 7 through 9 include the following:
|Energy performance measure (EPM)||Target area||Electricity reduction||Annual cost savings||Incremental first cost||Simple payback|
|High-efficiency lighting (0.8 W/SF)||Lighting||46,462 kWh/yr3.3%kWh/yr / %||$8,038||$30,000||3.7 years|
|Daylight harvesting||Lighting||31,811 kWh/yr2.2%kWh/yr / %||$5,503||$41,850||7.6 years|
|Optimized HVAC units||HVAC||5,122 kWh/yr0.4%kWh/yr / %||$886||$0||Immediate|
|Demand-controlled ventilation (CO2 sensors)||HVAC||66,378 kWh/yr4.6%kWh/yr / %||$11,483||$47,520||4.1 years|
|Master plug load shutoff switch*||Plug Loads||86,069 kWh6%kWh / %||$14,890||$45,000||3 years|
Measurement and Verification
|Companies and Roles|
|Gardiner & Theobald
Energy project director
|AMA Consulting Engineers
Energy consultant and modeler
Energy incentive consultant
|Empire State Realty Trust
Although Global Brands Group’s space was already submetered, the company chose to conduct a ten-day measurement and verification (M&V) period once the space was operational to determine whether the EPMs were performing as intended. The M&V period would track energy use at the panel level, allowing Global Brands Group to monitor plug load, HVAC, and lighting electricity independently.
The M&V period revealed that all EPMs were operating as designed, but that the original energy model had underestimated overnight and weekend electricity consumption. The following recommendations were made following M&V:
- Careful attention should be given to operation of electric heat, a notoriously large contributor to wasted energy, as well as commissioning of the HVAC fans to ensure they are not running during unoccupied hours.
- Lighting control schedules should be confirmed. Metered data showed that lighting load peaks do not taper off until two to three hours after plug loads decrease, indicating lights may be left on even after occupants have left for the evening.
Empire State Realty Trust encourages tenants to use the Tenant Energy Optimization process in all new buildout projects. Global Brands Group used its experience implementing the process on floors 7 through 9 to inform the buildout of subsequent space in the Empire State Building.