Liberty Green and Liberty Luxe
New York, NY
With its pedestrian-friendly sidewalks, mix of uses, and urban fabric of residential towers interwoven with ample parks and green space, Battery Park City (BPC) was an early forerunner of more sustainable patterns of development that have emerged since its masterplan was unveiled in 1979. In 2000, the BPC Authority built on this legacy, becoming one of the earliest large-scale developments to adopt comprehensive sustainability guidelines governing energy efficiency, water usage, and indoor air quality. Now rising on the last two remaining sites at Battery Park City, EE&K’s design for the Liberty Luxe and Liberty Green residential towers represent the culmination of this original vision and a template for sustainable high-rise living in the future.
Liberty Green and Liberty Luxe incorporate advanced green features and systems at all levels, including building construction and maintenance. The twin buildings are at least 30% more energy efficient than their typical New York City counterparts and exceed both LEED Gold requirements and the Battery Park City Authority’s own sustainability guidelines. Liberty Green and Liberty Luxe achieve one of the city’s lowest carbon footprints, while allowing residents to live in comfort and style with access to all the neighborhood’s prized amenities.
The challenge for EE&K was to create a strong contemporary design that integrated the latest standards in sustainability rather than treating them as additive features. To do so, EE&K undertook an integrated design process, leading a team of environmental and engineering specialists to address building envelope, energy, lighting and HVAC strategies.
Building Envelope Strategies
75% of the buildings’ open roof areas are planted with indigenous plantings, providing higher than Code-required levels of insulation. These green roofs minimize the occurrence of heat island effect and reduce the amount of heat gain and loss through the roofs. Air-tight wall construction and air-tight windows ensure the optimal performance of summertime cooling and wintertime heating systems, minimizing costly air leakage.
Liberty Green and Liberty Luxe rely on three Combined Heat and Power Units (CHPs) to generate a significant portion of the buildings’ electricity use (28%), domestic hot water needs (70%), and heating needs (31%). The CHPs capture the waste heat created by the production of electricity and then use this heat to produce hot water for the building’s domestic and building heating systems. In addition to the CHP units, photovoltaic panels integrated into the buildings’ façades produce at least 5% of residents’ peak electricity demands.
In order to reduce lighting loads, the buildings employ a range of lighting strategies including occupancy sensors for areas like corridors and stairs; fluorescent lighting in the apartment kitchens, halls and bathrooms, and daylight sensors to minimize exterior light usage.
Heating, Ventilation and Cooling (HVAC) Strategies
As part of their HVAC strategies, the two buildings feature high-performance water loop heat pumps and individually programmable thermostats for apartment heat pumps. Two of the greatest cost-saving features are high-efficiency hot-water boilers and water-cooled DX air conditioning units. The garage employs carbon monoxide sensors to reduce fan electricity use during periods of low or no traffic.
Indoor Air Quality
Liberty Green and Liberty Luxe’s superior indoor air quality begins with rigorously monitored construction practices to ensure dust, mold and allergen control. Each apartment has a fan-powered exhaust system; bathrooms have continuously running exhaust. The buildings’ HVAC systems provide humidity stabilization throughout the year via high-efficiency gas-fired boilers and recycled condenser water from the cooling towers.
The buildings achieve significant water savings through a blackwater system that cleans, filters and re-uses the waste water in toilets and the cooling towers. All the plumbing fixtures are water efficient. Storm water retention tanks enable the reuse of rain water for irrigation and outside maintenance needs.