Mixed Use Carbon Neutral Design Wins ASHRAE LowDown Showdown

Project was selected as winner of the international competition where teams collaborate to design a building based on real-world challenges.

Aequitas exterior

HGA presented at the virtual 2020 ASHRAE LowDown Showdown event and won First Place in the international competition. Aequitas, an integrated team of designers, architects, engineers, and sustainability experts, worked together to create a 300,000 square foot, 15 story mixed-use building located in New York City. The challenge required the design of carbon-neutral building that would contain retail space, residential space, and a full-service restaurant.

About Aequitas

Aequitas, the Latin origin of the English word “equity”, became the driving factor for the design. The team aimed to achieve positive impacts for all – promoting resident and community health and well-being, fostering positive economic conditions in the region, and reducing climate change impacts. HGA’s integrated architecture and engineering team approached this mixed-use project with the aim of designing a Net Zero Energy building that demonstrated holistic sustainability, equity, and resilience.  Team members are: Elizabeth LeRiche (Sustainability Specialist), Michael Hara (Architect), Ethan Fogle (Structural Engineer), Ariane Laxo (Sustainability Director/Advisor), Leighton Deer (Mechanical Engineer/Advisor), Manus McDevitt (Net Zero Expert/Advisor), and Graham Linn (Energy Modeler).

The project minimized embodied carbon, provided community resources, offered generous green space, and achieved long-term resiliency in the face of increasing temperatures and extreme storm events. The building integrates occupant comfort, beautiful design, and healthy materials – and makes these assets accessible to all. The architectural design is driven by a balance of both contextual neighborhood cues and functional performance. Borrowing its language from the adjacent industrial area, the building’s primary façade echoes the design of nearby warehouses. Layered onto this are functional elements that augment the building’s performance including narrow, light-filled floor plates, natural ventilation, solar PV horizontal louvers, and high-performance envelope systems. Enhanced thermal-mass walls, roof insulation, triple-pane glazing, and a 40% window-to-wall ratio balances passive solar gains in winter with reducing peak summer loads, resulting in a well-balanced and high performing envelope.


Resiliency measures are integral to the design solution. The choice of a concrete structure for the first two levels assures structural integrity in the case of future flash flooding events. The integration of green roofs and community gardens reduce heat island effect, assist with air quality, and are integral components of the stormwater management systems. Additionally, the building is equipped with a 12 MWh battery to power essential loads in the case of a power outage during a storm; supplemented by the envelope’s thermal mass it can sustain a habitable interior temperature for passive survivability. The mechanical room housing the battery storage is located on the second level to protect equipment in the event of flash flooding.


Aequitas urban farm view

The building employs a number of strategies to collect renewable energy and achieve carbon neutrality. The southeastern façade features a unique unitized system that has integrated solar PV panels. These panels both collect solar radiation for renewable energy and act as horizonal louvers to bounce natural light deep into the space. The site, located adjacent to several train tracks, also utilizes a futuristic energy harvesting system which converts train vibrations into electricity for use in the building.


Aequitas interior

The HVAC systems provide an enhanced level of thermal comfort and indoor environmental quality with minimum use of fossil fuels. The core of the heating and cooling system is a series of sequential water to water waste source heat pumps that produce simultaneous chilled water and hot water from the site-adjacent sanitary sewer main. The reduction in the total building energy usage and peak heat loads allowed for the building to fully utilize the sanitary system, as a more typical building energy usage would be greater than the heat capacity of the sanitary main. In addition, a combination of chilled beams with radiant floor systems and axial ceiling fans provide the comfort control in each space. A central dedicated outside air system (DOAS) will provide the ventilation air for the building.

Aequitas sky garden view

To achieve the desired reduction in embodied carbon, the team selected mass timber for the primary structural system. At 15 stories, this building would be one of the tallest mass timber structures in North America. The specification of concrete, foam insulation and aluminum were minimized. Where concrete is used, a low carbon mix is specified, supplied by plants with CarbonCure technologies. Wood fiber board provides continuous exterior insulation and sheathing. Dense-packed cellulose is used for stud cavity insulation, and windows with timber frames minimizes the use of aluminum.
Together, these strategies achieve a Net Zero, sustainable building that will become a beloved community amenity, weather future climate change impacts, foster equity, and enhance the wellbeing of residents and neighbors alike.

To learn more or view our entry, visit ASHRAE LowDown Showdown.

About the ASHRAE LowDown Showdown

The ASHRAE LowDown Showdown modeling competition engages teams comprised of building analysts, designers, architects and engineers in a collaborative and fun learning experience that explores new advances in building science, modeling and technology. Participants work as integrated teams to create effective workflows and an outstanding designs to address real-word building efficiency challenges.


Founded in 1894, ASHRAE is a global professional society committed to serve humanity by advancing the arts and sciences of heating ventilation, air conditioning, refrigeration and their allied fields.

As an industry leader in research, standards writing, publishing, certification and continuing education, ASHRAE and its members are dedicated to promoting a healthy and sustainable built environment for all, through strategic partnerships with organizations in the HVAC&R community and across related industries.

ASHRAE is celebrating 125 years of shaping the built environment.

To learn more about the ASHRAE LowDown Showdown, visit ASHRAE.