Party walls shared by adjoining townhouse are ubiquitous in Manhattan and, as recent case illustrates, are an invitation to litigation– especially where a sale at an astronomical price is followed by a massive top-to-bottom renovation.

Kai and Doris Chang own a townhouse on East 92nd Street. A limited liability company (LLC) owns the townhouse next door. The party wall is 40 feet high and was originally one foot thick.

The LLC hired Trident Restoration to do extensive renovations on its property, including relocating the bathrooms and kitchen and altering the building’s plumbing.

The Changs discovered a hole in the third-floor bedroom of the their townhouse; pipework anchored brackets installed on their side of the party wall, running the full height of the building; and another hole on the second floor, directly under the third-floor breach.

The Changs' professional engineer found that substantial portions of the party wall had been removed; the renovation failed to conform with the plans and drawings filed with the Department of Building; and compromised the fire separation rating of the party wall in violation of City building codes.

The Changs sued for trespass damages, and injunction and restoration of the party wall.

The LLC hired an engineer. The two engineering firms inspected the work and prepared reports regarding the fireproofing and integrity of the party wall. The Changs' engineer found areas of missing brick within the property line of the Changs' townhouse that should be replaced. The LLC engineer's responsive report stated that “[w]hile the wall structural integrity has not been compromised, the contractor will repair all locations where openings [in the brick] were noted.”

The Changs reported additional damage: six new holes in a third-floor room. The LLC and Trident conceded that the holes were drilled in error and offered to repair the holes at their cost.

The Changs alleged that the LLC and Trident had built an additional wall (which they refer to as a “concrete masonry unit” wall) on top of the party wall on the roof; the additional wall encroached onto their side of the party wall by two inches; and the encroachment existed along 55 feet of the party wall. They also alleged that a new cable box rested on their side of the party wall.

The Changs later discovered new damage to the fourth floor of their townhouse—the attachment of a cable to the new cable box, and the fastening of the cable to their rooftop gutter. The Changs claimed that the cable prevented them from properly cleaning the gutter, causing the gutter to overflow and cause water damage on their side.

The Court could not determine whether that work had been completed. And the LLC and Trident did not establish that the party wall in its current form matched the drawings filed with the DOB.

The LLC and Trident asserted that the reports exchanged between the engineers demonstrated that the party wall was not load-bearing and that its structural integrity remained intact. The Court was unpersuaded.

The Court found that some of the LLC and Trident's’ alleged conduct, in drilling through the party wall and installing pipework, was an encroachments/ trespass or private nuisance.

The Real Property Actions and Proceedings Law provides that “[a]n action may be maintained by the owner of any legal estate in land for an injunction directing the removal of a structure encroaching on such land.” So the Court found that the Changs could seek injunctive relief to abate a private nuisance.

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