(Digital) twin studies

Medical researchers use twin studies to separate the influence of genetics from environment. Engineers from the University of Pittsburgh and the University of Central Florida are doing something similar with buildings, studying Pitt's Mascaro Center for Sustainable Innovation alongside its digital twin to separate design intent from day-to-day reality. 

The team has built an interactive virtual twin that blends blueprints and models with sensor data and sustainability analyses. As a counterpart to the physical building, it lets researchers and facility staff “walk” through a 3D version of the building, click on rooms and systems, and see color overlays, pop‑ups, and alerts that reveal in real time where energy use, indoor air quality, or materials require attention.

This research, “Digital Twins for Sustainable Buildings: From Framework to Strategy Guidelines and Application” (DOI: 10.1016/j.enbuild.2026.117332), provides a novel framework combining digital twin technology with sustainability assessment.

“With this framework, we are moving beyond static snapshots, making steps toward a dynamic record of a building’s environmental footprint, from the materials in its structure to the air its occupants breathe,” said Federica Geremicca, a postdoctoral researcher in civil and environmental engineering at the Swanson School and first author of the paper.       

An ideal case study

When it was built in 2009 as a hub of sustainable innovation on Pitt’s Oakland campus, the Mascaro Center for Sustainable Innovation (MCSI), a LEED Gold building, was equipped with sensors that monitor everything from energy consumption to air quality to Heating, Ventilation, and Air Conditioning (HVAC) flows. The sensing technology and the centralized Building Automation System (BAS) that controls it provide researchers and building managers with data that can help guide sustainable decision making.

“We’re collecting all this important data, but it hasn’t always been easy for researchers to access and can be siloed and inconsistent,” said Melissa Bilec, George M. and Eva M. Bevier Endowed Chair in Civil and Environmental Engineering and co-director of the MCSI. “We set out to develop a digital twin of the Mascaro Center that would transform how the data is processed and visualized, so we could better see how the building is functioning.”

The research began in the fall of 2023, after the team received a $735,872 National Science Foundation grant to develop new tools to enable climate adaptivity in vertical infrastructure.

A living model

Essential to developing a digital twin is the Building Information Model (BIM): a detailed 3D model, or blueprint, of how a structure is built. In buildings, this static BIM provides the backbone of the digital twin. The team connected the BIM to the BAS, which gathers measurements like temperature, humidity, ventilation, and indoor air quality. It also integrated sustainability methods: Material Flow Analysis (MFA), which tracks what materials go into, stay within, and leave a building over time; and Life Cycle Assessment (LCA), which estimates environmental impacts across the building life span.

Underpinning the research is the concept of urban metabolism (UM), or the flow of resources through a city. UM represents a city as a living thing, and just as a healthy metabolism is important in humans, so it is with a city or a single structure within it.

Built in Unreal Engine, an immersive 3D visualization platform, the interface of the digital twin offers a third‑person walkthrough of the Mascaro Center. “Instead of reviewing static dashboards, you can walk around the virtual Mascaro Center and click on components in rooms. You can see heat-map overlays that highlight material-intensive components and find out how systems are performing, and when something needs attention,” said Geremicca.

Developing the new framework posed unique challenges. “We encountered gaps in the data and inconsistent labeling and units in the Building Automation System,” said John Brigham, professor of civil and environmental engineering. “There were privacy constraints that complicated validation and automation.”  

The team also had to adapt the modeling detail. “The Mascaro Center has unique shapes and slanting walls, and though it may sound counterintuitive, we had to scale back the level of detail to more effectively integrate the energy analysis software,” Bilec said. The team learned that the visual twin and the analytical twin benefited from different levels of detail.                                                                                             .

They also gained valuable insight into the building itself. The model showed how the floors and columns carried most of the building’s material “weight,” and how the replacements that occur over the life of the building can have a significant environmental impact.

“Moving forward, we’ll continue to explore ways to improve how the data is collected and integrated into the digital twin,” said Alessandro Fascetti, Associate Professor in the Department of Civil, Environmental and Construction Engineering Department at the University of Central Florida. “We’re excited to take what we’ve learned and expand the framework to buildings around the Mascaro Center.”

“From its inception, the Mascaro Center was designed to embody sustainability in how it was built and how it’s used,” said Bilec. “The digital twin helps fulfill that vision by turning all this data into a visually interesting interface that fuels better decision making. This research lays the groundwork for smarter, more sustainable operations and more advanced automation. Importantly, this work was inspired by and in honor of Jack Mascaro, MCSI’s namesake and founder, who guides us every day to be on the cutting edge of technology, innovation, and sustainability.”