In a dense urban environment, nearby demolition, excavation, and construction can pose a serious structural threat, particularly to the type of simple, economical row houses that proliferated in Philadelphia in the 19th and 20th centuries. The city has seen a number of collapses due to illegal construction activity, including the recent dramatic collapse of a twin house in Fishtown due to an illegal basement excavation next door. But even when permits and proper construction plans are in place, a risk remains. Part of the issue stems from a basic misunderstanding of, or perhaps disregard for, the fundamental nature of the city’s iconic building types: the row house and the twin.

It Could Happen to You

“I first started seeing these cracks over here, after they underpinned the building,” explains Maggie Manzer as she walks me through her row house in South Philadelphia. The three-story house, which Manzer purchased in 2010, is much deeper and roomier than the narrow facade lets on, with large windows along the shared alley letting in a generous amount of light.

She and I stand together in a room on her second floor, examining a web of cracks emanating from the upper corner of the south wall. The sheer number of them is alarming.

“When I saw the cracks on the third floor, then I got really worried,” she says as we climb the stairs. “I’ve owned this house for eight years and I’ve had a couple of hairline cracks, but none of these.” Manzer gestures around the room. “The whole ceiling in every room in the front of the house, above the doorways, everything is cracked.”

According to an engineering report, this cracking is the result of settlement due to the underpinning and backfilling of her foundation. The procedure, initiated by the neighboring owner, caused the front of Manzer’s house to settle and the facade to pull ever so slightly away from the rest of the building.

After an adjacent one-story property, formerly an auto garage, was demolished to make way for a new 39-unit apartment building, a geotechnical engineer determined that the foundation of Manzer’s house needed to be underpinned prior to the excavation for the new building’s basement and foundation.

The process is intended to strengthen the foundation of a building and involves systematically excavating under portions of the building’s existing foundation, injecting cement, letting it cure, and continuing until the entire foundation is supported. It is required when adjacent construction might impact the stability of the ground that an existing building sits on, usually when a nearby excavation will extend below the current depth, or a new structure will have a significantly different bearing load on the neighboring soil.

Although Manzer had been in contact with OCF Realty throughout the demolition process—OCF brokered the acquisition and assisted with the zoning process for the project next door and is now the rental manager for the apartment building—she had never been contacted by the owner, an entity listed as 1433 Federal St, LLC, which, according to Manzer, is owned by a local personal injury lawyer named Michael Garnick. Notably, Garnick was one of four men arrested in 2017 on charges of fraud conspiracy and money laundering conspiracy. As a result, she was under the impression that OCF was the property owner throughout the early phases, since they had been the only entity coordinating with her throughout the process.

The Philadelphia Building Code requires that property owners be notified within 10 days of excavation. But Manzer, who was working in New York at the time, did not receive notice that her property was going to be underpinned.

Shortly after the procedure was finished, Manzer noticed that her house had shifted on the south side. Alarmed—the shift was so significant that her front door no longer locked—she promptly notified staff at OCF, who until then had been her only point of contact. A representative from the contracting company came the next day to drill out the lock so that the door could engage, returning multiple times to repeat the procedure as the house continued to settle over the next two months.

As we continue our tour, Manzer points out places where windows no longer shut and where doors swing open. When we make it back out front it is clear that the entire facade is pulling away from the upper stories of the building, listing ever-so slightly towards the sidewalk. Cracks weave through the permastone cladding, across lintels, radiating from the corners of the front windows.

For now, the facade is temporarily braced with steel L-brackets applied by the contractor, also done without Manzer’s permission, but the temporary fix doesn’t address the structural damage. To properly repair the damages, including replacement of the facade, Manzer has received a quote in the ballpark of $100,000.

Following the damage, Manzer continued to communicate with OCF Realty. An OCF representative let Manzer know that the owner was unwilling to accept responsibility for any damages, but would offer her a $10,000 to $15,000 “good-faith” payment if she would be willing to sign a Hold Harmless agreement. Manzer declined the offer on the basis that the amount would not be adequate to repair the damage and instead contacted the general contractor, Top Gun Enterprises, to see if it would be willing to make a claim on their liability insurance to cover the damages. It was not. 

In the meantime, she’s been left with little choice but to pursue legal action by bringing lawsuits against all parties involved, including OCF Realty, 1433 Federal St, LLC, Top Gun Enterprises, the engineering firm that developed the plans for underpinning and provided the supervising engineer, the concrete contractors, and the demolition contractor.

When I first talked with her last year, she’d sunk the entirety of her savings and then some into covering the legal fees. Now, nearly a year later, her expenses have more than doubled, totaling around $50,000. She’s also lost nearly all of the equity in the house.

While the contractor and engineer are required to carry liability insurance to cover the cost of any damages and associated legal fees, Manzer’s homeowner’s insurance doesn’t cover any of the damage in this particular situation. Because the insurance inspector found that the damage was caused by “man-made earth movement,” it didn’t trigger coverage.

According to Kevin G. Amadio, an attorney with the law firm Kaplan Stewart who is familiar with cases like Manzer’s, each case is different and a builder or developer’s liability coverage “may cover that party’s liability to the homeowner, depending on what events caused damage to the homeowner.”

Manzer is hoping that the parties involved can reach a settlement that will cover all of the necessary repairs and her legal fees, but if not, the case will go to trial.

Many homeowners find themselves stuck trying to navigate similarly frustrating issues with limited support. While researching this story, I reached out to homeowners to try to get a sense of how common these kinds of problems are. A number of people responded to recount their tales of damage, many of whom felt similarly confused and frustrated about where to seek help and advice while navigating the process.

When searching for assistance via City government resources, such as Licenses and Inspections (L&I) and 311, many reported being told that legal action was their only option for recourse. Manzer and other homeowners also reported contacting their local City Council representatives and receiving more or less the same response.

A representative from Community Legal Services, an organization offering free civil legal assistance to low-income Philadelphians, said that the organization receives fairly regular calls about issues related to adjacent construction, but are not able to prioritize them and will usually refer callers to Philadelphia VIP, another pro-bono legal service. Still, many homeowners simply can’t afford to even initiate legal action, or may be reluctant to go through the hassle if the damages aren’t substantial.

Row House Fundamentals

To get a better sense of the fundamentals of row house design and the structural implications of disrupting a row, I spoke with structural engineer Justin M. Spivey, who specializes in renovation, repair, and reuse of existing structures and has taught preservation engineering at Johns Hopkins University.

Spivey classifies row houses as a “vulnerable structure type.” Fundamentally, Spivey says, row houses are built to function together as a group. Party walls—that is, the walls that are shared between adjacent homes—are typically only two wythes of brick thick. That means, a mere two rows of brick, and typically a soft, salmon brick not meant to withstand exterior exposure, is often all that stands between your house and your neighbor’s.

Imagine a block of row houses, with the two houses at each end providing bookends of support. The houses at the interior of the block are reliant upon on the entire block unit for optimal structural support—those row house party walls weren’t designed to resist lateral loads on their own. When a tooth in the row goes missing, there may be no immediate damage observed, but the overall structural stability of the remaining houses has indeed been compromised.

“The removal of one home from a row can have several negative impacts on structural stability,” Spivey explains. “The removal of floor and roof joists from one side of a party wall often means that the wall is no longer effectively braced against buckling in that direction, unless joist-to-wall anchors are installed as demolition proceeds.”

During this conversation, Spivey shared an image with me of a row house where its neighbor had been demolished that had been effectively braced. It was certainly not what I usually see in Philly, with large, secure-looking bolts sticking out at regular intervals through the bare, stuccoed party wall, securing the joists along each floor. Properly stabilizing the home in that case, Spivey estimated, probably cost around $100,000.

Additionally, when that soft brick of a party wall is left exposed to the elements, or concealed behind an incompatible impermeable coating like cement, water infiltration, freeze-thaw, and other agents can lead to significant deterioration.

But the biggest threat, as Manzer’s case and many others can attest, is when neighboring activities involve excavation adjacent to or below existing foundations. “The resulting changes in soil bearing pressures and support conditions can cause structural movement, resulting in cracks in masonry, plumbing leaks, cracks and separations in interior finishes, sloping floors, problems operating doors and windows in out-of-square openings, and in extreme cases, loss of support where floor and roof joists bear at pockets in masonry walls,” Spivey says.

What to Do?

In a city full of shared walls, what can homeowners do? Attempts at prevention are a start. According to Spivey, “The risk of future damage is typically lower on projects where neighbors proactively communicate, where qualified design professionals are hired to assess the risks and develop mitigation strategies, and qualified contractors are hired to implement them.” Still, sometimes the planning phase feels out of the neighbors’ control.

I reached out to Karen Guss at L&I, who explained the City’s requirements for underpinning and adjacent demolition and what homeowners should do if they notice any issues.

According to Guss, City regulations state that any underpinning must be authorized by a building permit and the construction plan must include plans prepared under the direction of a professional engineer licensed in Pennsylvania. “The plan must identify existing construction, sequence of underpinning, and any additional protections necessary to preserve the integrity of the structures.”

The procedure must also be regularly inspected and monitored by a professional engineer and “The engineer must monitor the site continuously during the excavation and placement of concrete.” The contractor must also contact L&I to arrange for regular, required permit inspections.

City Code also requires that any homeowners demolishing their portion of an attached structure must seal all cornices that have been cut, remove any loose material, fill any breaches in the wall that have been exposed, and install some form of weather-resistant wall covering.

Still, Manzer and other homeowners were left feeling that they had few rights and little support. Many called 311 and L&I to report damage. Both agencies responded that they could not send an inspector out without proof that the builders were violating their permits.

Frustrated by witnessing similar situations, Venise Whitaker, a Fishtown resident and community activist who is active in the Philadelphia historic preservation scene, started the Facebook group Riverwards L+I Coalition to provide a forum for neighbors to track and share information about construction projects, violations, and provide a documentary record of construction sites in the area. Whitaker, who keeps a running list of properties that have been undermined by adjacent excavations, says that the group has worked with L&I to “update and change codes” and provided input for the 2019-2021 Department of Licenses and Inspections Strategic Plan. 

I asked Spivey if he had any recommended resources for homeowners who’d like to better educate themselves about row house construction. He replied that there are unfortunately few, although the Delaware Valley Chapter of the Association of Preservation Technology held a free Row House Symposium earlier this year, and it is hoped that a publication will be forthcoming.

For approachable explanations of the risks associated with adjacent construction and demolition, he suggested reading the articles “Cases of Failure of Unreinforced Brick Walls Due to Out-of-Plane Loads” (Structure, May 2011, pp. 14-17) and “Development Along Old Party Walls” (Structure, June 2017, pp. 12-15), both written by Dan Eschenasy and available free online.

When contacted for comment, Ori Feibush, president and founder of OCF Realty, responded via email, “My office brokered the acquisition and helped with zoning before development and is now the leasing agent for the apartment rentals at the subject property. At no time was I managing the construction and at no time did I have any ownership of the property. I had zero involvement in the construction or development (beyond approvals). During construction, Ms. Mazer was unable to reach the developer, owner, or contractor of the project to resolve issues she experienced and I stepped in to try and connect the parties.  During that process, I paid out of pocket to help her with damage that occurred to her front steps from the developer and even put her in touch with a structural engineer.  I am aware that Ms. Mazer has included me in her litigation against the developer and regret to say that it’s an example of no good deed going unpunished.”

Michael Garnick and Top Gun Enterprises did not respond to Hidden City’s request for comment.