JBG Smith: L'Enfant Plaza East Building
Background
L’Enfant Plaza East is a 12-story building with both office and hotel space in Washington, DC. Renewed leases with the U.S. General Services Administration in 2010 and 2011 required the property team to achieve and maintain ENERGY STAR® certification. Recognizing that aging building systems presented an opportunity to vastly improve energy performance, JBG Smith began identifying and implementing numerous energy conservation measures.
The L’Enfant Plaza East Building was designed by a world-renowned architect in the late 1960s and construction was completed in 1971. The 12-story building features seven floors of office space leased primarily by federal government tenants, three floors of hotel space, and a ground floor lobby that serves both the office and hotel space. After renewing GSA leases in 2010 and 2011, the building was required to achieve and maintain ENERGY STAR certification by scoring 75 or above on ENERGY STAR’s 1 to 100 energy performance rating scale. In 2011, JBG set a goal for the building to achieve LEED for Existing Buildings: Operations & Maintenance certification and in 2014 the company joined the Better Buildings Challenge, renewing its commitment to reduce portfolio-wide energy use by more than 20%.
The property team regularly tracked resource consumption metrics in both ENERGY STAR Portfolio Manager and Ecova’s cloud based platform and initial ENERGY STAR scores for the building were in the mid 50’s. When the property established a baseline for energy performance in December 2010 with an ENERGY STAR score of 61, much of the lighting was inefficient T12s, the parking garage was severely over-lit with no controls, the building’s chillers were original and extremely inefficient Carrier 19EA 1000 Ton R-12 machines with an efficiency rating of .846 KW/Ton , and no VFDs (variable frequency drives) had been installed. JBG recognized that the building’s 45-year-old systems presented a major opportunity for energy savings. They enlisted the help of ThinkEnergy Management to conduct comprehensive energy audits for both the office and hotel spaces. A major renovation of the office portion of the building was completed in 2012, including significant infrastructure and common area upgrades. The property team implemented more than 30 different low- and no-cost energy conservation measures (ECMs) that were identified through the audits. In addition, the building enrolled in a demand response program with Energy Curtailment Service from 2012 to 2015, which helped identify tactics to reduce energy consumption not only during emergency peak demand periods but also from day-to-day operations. The team also partnered with Mach Energy in late 2013 to add real-time energy management capabilities. As L’Enfant Plaza East’s owner, JBG remains committed to additional energy performance improvements to far exceed the company’s Better Buildings Challenge goal of 20% energy reduction by 2021.
Solutions
The L’Enfant Plaza East team completed a comprehensive energy audit of both office and hotel space to identify and implement 35 energy conservation measures. These included major upgrades to many systems that were original to the 45-year-old building - installing new chillers, replacing lights and adding controls, installing variable frequency drives, and working with office tenants to reduce workstation plug loads.
JBG Smith implemented the following energy conservation measures:
- Overhauled penthouse equipment including installation of new 750-ton water-cooled centrifugal chillers with an efficiency of 0.55 kW per ton
- Installed 2 new pumps, motors and sewer ejector pit tank
- Installed VFDs on cooling tower fans, water booster pumps, and penthouse motors
- Exit stairwell lighting were 100 watt mercury vapor bulbs replace with 14 watt LED fixtures
- Replaced majority of T12 lighting in office areas with either T5 or T8 lamps and ballasts
- Removed personal appliances from GSA workstations to reduce plug load
- Installed high-efficiency T8 Limelight/Twist system in garage with both occupancy and motion sensors as well as wireless RF master controls, reducing total number of fixtures from 1,119 to 548
- Reset mechanical setpoints and refined other Building Management System settings
- Installed energy controls on water fountains to only operate during building hours
- Replaced constant-volume HVAC units with Variable Air Volume units to improve tenant control over space conditioning
- Installed occupancy sensors on all common area hallway and restroom lighting
- Replaced incandescent bulbs with CFLs in the hotel hallways and elevator lobbies
- Upgraded exit signs from (2) 25 watt incandescent bulbs to 7 watt LED
- Added lobby vestibule areas and doors to prevent energy loss when doors were opened
Other Benefits
The upgrades installed at the L’Enfant Plaza East building provided many benefits for the property including the ability to achieve ENERGY STAR and LEED® certifications and qualify for utility rebates and incentives. The renovation has also positioned the property to achieve long-term energy savings of an additional 10%. The technologies utilized also helped the property meet and exceed lease requirements for energy performance, thermal comfort, and ventilation.
In addition to reducing energy expenses, the upgrades implemented at L’Enfant Plaza East helped achieve an ENERGY STAR score of 82, representing a 25% improvement from a baseline score of 61. The property is also poised to achieve a LEED for Existing Buildings: Operations and Maintenance Silver certification in 2015. Additionally, newly-installed efficient systems and advanced metering and monitoring technologies will help the property achieve an additional 10% energy savings by 2024. The technologies leveraged for many of the upgrades qualified for rebates from the DC Sustainable Energy Utility. Finally, the upgrades implemented at L’Enfant Plaza East allowed the building to achieve energy performance requirements set forth in GSA leases without sacrificing thermal comfort or ventilation.
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