More than twenty years ago, Joy Squared Design Principal Sharon Gentges helped design the complete rehabilitation of the Interfaith Apartments in Boston’s South End while working at a previous firm. The scattered-site development with two historic Victorian-era hotels and two row houses had fallen into serious disrepair after years under public ownership. Working with nonprofit owner Haley House, who took over the buildings from the City of Boston, Sharon and her team undertook a comprehensive gut renovation that restored the historic buildings and returned them to service as affordable housing.
Two decades later, Sharon returned to the project, this time as part of Joy Squared Design, to help prepare the buildings for a phased deep energy retrofit designed to meet the City of Boston’s long-term climate goals.
Meeting Boston’s Path to Net Zero
Boston’s Building Emissions Reduction and Disclosure Ordinance (BERDO) requires large buildings across the city to track and reduce their energy use over time, with the goal of achieving net-zero emissions by 2050. For the two larger Interfaith buildings—the Chatham and the Albemarle—this meant developing a clear strategy for meeting upcoming emissions reduction targets and preparing a plan for future upgrades to meet the longer-term reduction targets.
Joy Squared Design partnered with engineers at Rimkus to conduct a comprehensive energy analysis. Together with Haley House and Maloney Properties—the development consultant and longtime property manager— the team developed a 15-year roadmap for reducing energy use while maintaining affordability and minimizing disruption to residents.
Rather than implementing all upgrades at once, the plan sequences improvements in a logical order that maximizes performance and financial feasibility.
Starting with the Building Envelope
The first phase of the retrofit focused on improving the building envelope, the foundation of any energy-efficient building strategy. At this stage, the team was joined by Matt Carlton, a building envelope engineer at RJ Kenny—coincidentally, a former colleague of Sharon’s who also worked on the original project and General Contractor Kaplan Construction.
The team completed extensive masonry repointing to ensure the historic facades were fully weather-tight. Insulation and air-sealing improvements were installed throughout the buildings, in cooperation with the LEAN Multifamily Program, along with targeted window replacement and refurbishment. These measures reduce heat loss, improve comfort, and prepare the buildings for future electrification.
Because the apartments remained fully occupied throughout construction, the work had to be carefully coordinated to minimize disruption for residents. The improvements delivered instant benefits.
“In one of the mansard units, you could actually feel cold air coming through the electrical outlets,” Sharon recalls. “Once the insulation and air sealing were completed, you felt the difference immediately.”
Sequencing the Path to Decarbonization
The envelope improvements represent only the first step in a long-term decarbonization strategy.
Future phases include:
- Energy recovery ventilation (ERV) systems to ensure healthy indoor air quality in the newly tightened buildings
- Electrification of building systems, transitioning away from fossil fuels with technologies such as heat pumps
- On-site renewable energy generation, potentially including solar installations, once energy demand has been reduced
This phased approach allows Haley House to pursue funding opportunities as they arise while steadily improving the buildings’ environmental performance.
Balancing Sustainability, Preservation, and Affordability
Like many buildings in Boston’s historic South End, the Interfaith Apartments fall within the South End Landmark District. All exterior work, including masonry restoration and window replacements, required review and approval from the Landmarks Commission.
Because the retrofit focused on restoring and improving existing materials rather than altering the buildings’ character, the review process moved smoothly. The result is a project that preserves the architectural integrity of the Victorian structures while dramatically improving their performance.
Stewardship Over Time
For Sharon, returning to the Interfaith Apartments decades after the original rehabilitation underscores the importance of long-term stewardship in affordable housing.
“These buildings were renovated more than twenty years ago, and they’ve been incredibly well cared for,” she says. “This project was about helping them take the next step, making sure they continue to serve residents for the next generation while meeting the city’s climate goals.”
By combining historic preservation, environmental responsibility, and mission-driven housing, the Interfaith Apartments demonstrate how existing buildings can evolve to meet resident, community, and climate needs.