Syracuse University

Background

“Historically, issues that can be easily seen and understood get addressed first in buildings,” said Nina Wilson, Ph.D., Assistant Professor of Architectural Technology at Syracuse University. Thus, one of the goals of Syracuse University’s net-zero retrofit of a 1970s-constructed apartment building was to render visible what isn’t readily seen: thermal comfort, indoor air quality, and energy efficiency.

The primary goal of the study was to produce a replicable model of a deep-energy retrofit that could achieve net zero energy in multifamily residential buildings of one to seven stories in height (see page ES-2 of NYSERDA’s RetrofitNY Market Characterization Study: Building Stock Assessment and Architectural Profiles of Predominant New York State Multifamily Building Types [PDF])—of which there are more than 600,000 that were constructed before 1978.

Thus, Syracuse University selected two identical eight-unit apartment buildings on Winding Ridge Road, both built in 1972, for the study. Both buildings had been operating with ventilation systems that did not provide adequate fresh air to the interiors, resulting in poor air quality. An examination of current conditions also found many problematic building components—including windows and doors with condensation and moisture issues.

Furthermore, the apartments were originally constructed using precast concrete with minimal insulation, resulting in poor thermal performance. Wall fins extending from the building's facade create thermal bridges, leading to heat loss. The building also used baseboard electric heaters with a rated coefficient of performance (COP) of 1 and lacked a cooling system. There was significant air leakage through windows, window frames, doors, and door frames, exacerbating energy inefficiency.

Called the Net-Zero Energy Retrofit Living Lab, the project was a joint effort of the School of Architecture, the College of Engineering and Computer Science, and the School of Information Technology, in addition to a general contractor and an architecture firm. The project was both a retrofit effort and a research study. One building, 341 Winding Ridge Road, underwent a retrofit, while the other, 351 Winding Ridge Road, served as a "control," providing comparable data throughout the study.

The first step was installing sensors for temperature, air quality, and window/door opening in apartments at both buildings. The team collected data one full year prior to, and multiple years following, construction.

Institutional Goals

Carbon neutrality by 2032

Funding and Financing

The total cost of the retrofit demonstration project and ongoing research was $1.59 million. Funding included a $1.39 million grant from NYSERDA’s Energy to Lead program and $200,000 from the Syracuse University Climate Action Plan. The Energy to Lead program supported the implementation of decarbonization projects with cost effective, deep energy savings that incorporated student engagement and encouraged the replication of projects elsewhere. NYSERDA has awarded more than $5 million to colleges and universities as part of this program.

Solutions Explored

The team looked into several insulation materials, including wood fiber insulation and sheep’s wool. They also explored installing ground-source heat pumps, on-site water storage, and green roofs. Many of these original project goals were scaled back in response to supply chain interruptions and increased construction material costs during the COVID pandemic. As the budget was intentionally kept tight to demonstrate the affordability of comprehensive decarbonization retrofit measures, some of these materials could not be implemented.

Initially, one project goal was to attain Passive House certification, but the amount of insulation and additional steps required to pass a blower test exceeded the modified project budget. That said, the team felt they learned what the EnerPHit Passive House certification would take and are ready to pursue that for future projects.

Solutions Implemented

Syracuse-based Northland Associates performed the retrofit of 341 Winding Ridge Road in an active partnership with Ashley McGraw Architects. They collaborated with the research and design optimization team to achieve energy and environmental quality performance goals while adhering to the budget.

After a year of pre-retrofit energy and IAQ monitoring, construction took place during the summer of 2022, when students were not in the residences. Once students moved back in, the retrofit team began monitoring and collecting post-occupancy data. Pandemic-related supply chain shortages delayed the delivery and installation of the photovoltaic panel array, which happened in October 2022. Monitoring and data collection on solar PV energy generation began at that time.

The retrofit had three primary targets: the building envelope, HVAC system, and on-site energy generation. The team upgraded the walls from three to five layers and insulated the entire enclosure with exterior insulated finishing systems (EIFS). They also added double-pane casement windows and new fiberglass-insulated exterior doors. They installed a heat pump system, providing both heating and cooling with an effective average COP of 3 (rated COP = 4.20). Additionally, two solar arrays and two heat recovery ventilator (HRV) units were installed. These HRV units operate on an alternating cycle, with one circulating fresh air indoors and the other discharging exhaust air outdoors.

Some building components remained unchanged, such as the lighting system, domestic water heating system, kitchen and bathroom exhaust fans, baseboard heaters in the bedrooms, and the roof.

Post-occupancy data revealed substantial reductions in energy consumption, with an almost 80% annual decrease in space heating, a finding further illustrated in a 2025 Nature journal article . The team noted improvements in indoor air quality (IAQ) and thermal comfort, with temperatures aligning more closely to ASHRAE standards than before the retrofit. Additionally, there was a recorded decrease in window use for ventilation. These positive outcomes are widely known to promote enhanced human health, occupant comfort, and improved cognitive performance.

At the end of the day, the project came very close to achieving its target of net-zero energy on a limited budget. But the award came at the start of the pandemic and construction material costs rose sharply, the team had to make some compromises. Sealing the building with “just enough” insulation and understanding the impacts of such ultimately contributed to significant reductions in energy consumption for space heating, which met project goals.

Timeline

• August 2021— pre-retrofit data collection from both buildings begins
• May 2022— pre-retrofit data collection ends and retrofit construction at 341 Winging Ridge Road begins
• August 2022— retrofit construction at 341 Winding Ridge Road ends and post-retrofit data collection begins
• May 2025— post-retrofit data collection for reporting ends, but will continue to analyze