By: Kelly Grogan
Published: March 26, 2020
Retaining walls hold back and support soil to allow for a difference in the elevation of the ground on either side. These walls are constructed in various shapes and sizes and consist of different materials. Each retaining wall is designed specifically to support the weight of the earth behind it and to allow for an adequate drainage system through the wall.
All retaining walls in New York City that are at least 10 feet tall and face a public right-of-way fall under the Local Law 37 of 2008 mandate. Much like the Façade Inspection & Safety Program (FISP), previously known as Local Law 11 of 1998, retaining walls must be inspected and maintained every 5 years. Age and weathering can cause spalls, cracks, and displacement in retaining walls in the same way we commonly see on brick masonry or ornamental stone. These retaining walls have to support soils that are constantly expanding and contracting in response to freeze-thaw cycles and shifting as adjacent properties erect new buildings, so it is imperative that the walls remain in good condition.
To satisfy the requirements of this local law, retaining wall inspections must be performed by a Qualified Retaining Wall Inspector (QRWI) who will classify the condition of the wall as Safe, Safe with minor repairs or maintenance, Safe with repairs and/or engineering monitoring, or Unsafe. A condition assessment report must then be submitted to the NYC Department of Buildings within a filing window based on the city borough of the property. RCNY-103-09 listed 5 filing windows from 2014-2018 corresponding with the 5 boroughs. After a 5-year cycle has been completed, the subsequent filing windows, by city borough, are as follows:
2019 – Bronx
2020 – Manhattan
2021 – Staten Island
2022 – Queens
2023 – Brooklyn
Like any inspection or maintenance item, these mandatory retaining wall inspections incur associated costs. However, it is worth noting that a building owner may not have to take on the costs of repairing a shared retaining wall, alone. According to NYC Administrative Code §28-305.1.1, if a retaining wall is located on the property line between two adjacent properties, it is a shared responsibility between the two buildings. Thus, each owner is responsible to split the costs of maintenance and repairs.
It is easy to feel frustrated with the cost and inconvenience of keeping up with the necessary maintenance, but it is important to step back and remember that this law protects the public by preventing future catastrophic failures. As discussed in Michael Frech’s article, “Retaining Wall Inspection Requirements”, the NYC DOB launched Local Law 37 of 2008 in response to the collapse of a retaining wall on the Henry Hudson Parkway in 2005.
Even if a retaining wall on your property does not face the public right of way, maintaining it can prevent hazardous incidents for residents and visitors. If there are visible signs of shifting or deteriorating masonry, we recommend that a QRWI or Structural Engineer with retaining wall experience is retained to conduct a hands-on inspection and evaluate the condition and stability of the retaining wall to provide a repair and maintenance scope. Addressing drainage issues and monitoring vulnerable wall penetrations can prevent expensive and avoidable structural repairs down the road.