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Stoneweg: Energy Conservation through Building Automation Systems

The pilot was initiated at 12 communities across eight states, reflecting the broad geographic footprint of Stoneweg US’s real estate investments. Implementing a diverse geographical and vintage portfolio of multifamily assets posed challenges, like the lack of MEP drawings and floor plans for locations that were constructed decades before being acquired. Stoneweg US was able to address this challenge by leveraging relationships with flooring contractors to produce the required drawings and accurately place the sensors.

The technology was deployed in a systematic way. First, Stoneweg US’ Sustainability Analyst worked with property managers and maintenance supervisors to obtain floorplans, current thermostat configuration, and any other necessary information. Then they submitted this information to the technology providers team for review. Finally, the technology was installed at clubhouses accompanied by community events which promoted a sense of ownership among the occupants and staff.

After installation, feedback loops were established to ensure that the process was continually refined: The system factors in occupancy relative to the time of day, outdoor temperature, and comfort of the occupant. “Comfort Buttons” allow the occupants to indicate if they are too warm or too cold. This establishes a best practice comfort range for the space depending on the above factors. If occupants are too cold during the summer due to the temperature indoors, the system learns that it does not need to run the HVAC as much during the day. The reverse applies to the winter and heating. Additionally, with occupancy sensors, the technology learns what time the spaces typically become vacant and adjusts the temperature accordingly. 

In the beginning stages of the project, emails went out to all staff who would be directly interfacing with the equipment. The goal was to ensure everyone felt a sense of ownership over the project and that it was not just something handed down to them by the property owner. This opened a line of communication between property managers, regional managers, Stoneweg US’ Asset Manager and Sustainability Analyst, and the technology provider. On installation days, Stoneweg US purchased food for all those impacted by the project. This brought higher attendance on installation days, which also served as informational sessions to educate on-site staff and residents about how to use and troubleshoot the technology. As positive data started to come in, excitement was spread to other properties that were in line to receive the technology. Feedback from community managers emphasizes how the system doesn’t just save energy but also fosters a sense of well-being among occupants and staff. Occupants appreciate being able to express their comfort level in a room with the push of a button while staff value the ability to remotely control their clubhouse’s HVAC system through a simple dashboard.

For all efficiency projects implemented at Stoneweg US (including this pilot), success is measured by the established expectation of a five-year return on investment; projects with an ROI greater than five years are not pursued. Additionally, projects are not considered successful if they directly inconvenience the site staff or occupants in a community.

Stoneweg US receives monthly impact reports that provide updates on data points being tracked by the system. The information provided in these reports include HVAC energy use reduced by the system, average HVAC runtime per thermostat per day, comfort insights (i.e. number of “too hot” votes and “too cold” votes), and peak occupancy times. The “Hot and Cold” buttons on the thermostats are used to provide real time feedback that could be equated to thermal comfort and satisfaction within the space.

This initiative continues to deliver positive results and supports Stoneweg US’ sustainability action plan, which strategically prioritizes improved efficiency and human comfort. By harnessing energy-efficient technologies, the company delivers measurable financial, social, and environmental benefits. 

This pilot showcases the potential of low-cost, simple retrofit technologies that can reshape energy consumption patterns, enhance user experience, and help with proactive maintenance of leased spaces. Since the initial technology deployment in 2022, monthly average energy use improved by an average of 15% across the buildings where the technology was deployed. However, buildings are seeing mixed savings results, with some showing a slight increase in energy use and cost while others show a large decrease. This is expected from a system that allows for manual inputs to adjust for human comfort. 

Although precise cost savings are pending utility bills, a project tracker tool has estimated annual cost savings of the entire system to be $17k which offers a payback period of just over 2 and a half years. As the machine learning technology continues to progress and the deployment process is refined, energy and cost savings are expected to improve over time. 

Stoneweg US utilizes a dashboard which serves as a central hub for all sites that employ the technology. On-site and off-site staff can monitor temperature, satisfaction, and occupancy data through the hub and can set schedules for temperature ranges, allowing for remote control when away from the site. They can also receive alerts regarding offline technology and can turn smart plugs on and off through the dashboard. The dashboard also displays floorplans for the spaces, and locations of the sensors in each room where users can access real-time information. 

Screenshot of temperature and humidity data

Example of a 7-day Temperature & Humidity data display from the dashboard 

Screenshot of a chart that shows real-time HVAC data

Example of a real-time data display from the dashboard