Historic buildings have a way of making us slow down. Maybe it’s the craftsmanship you don’t see much anymore, if at all. Maybe it’s the feeling that the walls themselves have stories to tell. Either way, preserving these structures takes not only a level of admiration, but also careful planning and technical expertise.
As Building Envelope Consultants, Duffy Engineering often works behind the scenes to help preserve the character and integrity of historic structures while solving the age old problems that continue to threaten them, from water infiltration, to deteriorating masonry and aging waterproofing systems, to structural movement.
In recognition of Historic Preservation Month, we’re highlighting three projects that show how our restoration work protects history for the next generation.
At Larchmont Avenue Presbyterian Church in New York, Duffy was retained to perform a building envelope survey for the nearly century-old Neo-Gothic campus. What began as an assessment evolved into a full restoration effort after the church embraced Duffy’s repair recommendations and long-term preservation strategy.
The project included stone masonry repointing and cleaning, slate roof repairs, stabilization of settlement cracks, and reconstruction of key areas to install modern waterproofing and flashing systems. While much of the work focused on restoring the building’s historic appearance, many repairs were also designed to address active water infiltration impacting interior spaces.
One particularly interesting discovery came during Duffy’s investigation into deteriorating decorative cast stone elements around the church entrances. The damage patterns didn’t match typical weathering, prompting further research that traced the issue back nearly 100 years to the original manufacturing methods. Using guidance from a National Park Service preservation brief, our team determined the cast stone was likely produced using a “dry-tamp” fabrication process — a method known to create hidden defects over time. It’s the kind of detective work that historic preservation often requires.
In Brookline, Massachusetts, Duffy was involved with two very different properties tied together by the same goal: extending the life of important buildings in Brookline’s history.
At 1-5 Winchester Street, a collection of early 1900s brick and limestone apartment buildings designed by architect W.H. Andrews, Duffy completed a façade survey and capital planning study as part of Brookline’s required five-year inspection program. The survey identified deteriorated mortar joints, cracked limestone, and aging masonry elements that now guide ongoing repair efforts. Projects like this help owners proactively preserve historic façades before small issues become larger structural or safety concerns.
Meanwhile, at Brook House Condominiums, Duffy approached preservation from a slightly different angle. Originally designed by renowned architect Clothiel Woodard Smith, the property had longstanding waterproofing failures at its mezzanine plaza level. Water infiltration had caused deterioration within the concrete structure below. Duffy developed a restoration design that paired modern waterproofing technology with updated plaza finishes, helping preserve the building’s functionality and architectural legacy.
And yes — according to local lore — Larry Bird would from time to time enjoy a few beers on the mezzanine benches.
Historic preservation is often associated with architecture and aesthetics, but behind every successful restoration is performance. Buildings need to keep water out, withstand weather, and safely support the people inside them. The building envelope plays a critical role in making that happen. For all of us at Duffy Engineering, preserving history means helping buildings to continue serving communities long into the future.
Sometimes, that starts with opening the envelope.
