Building owners who have retaining walls on their property typically don’t give them much thought. Unlike the facades of their building, retaining walls are often out of sight, out of mind. But if not regularly inspected and maintained, these walls can deteriorate and eventually collapse from constant exposure to soil, seasonal changes, vegetation, and age.
In one high-profile incident, a 75-foot-high, 150-foot-long section of a retaining wall at Castle Village co-op in Washington Heights collapsed onto the Henry Hudson Parkway in 2005. Reconstruction of the wall took more than two years and cost $24 million.
Local Law 37/08
Most New York City property owners and managers are familiar with Local Law 11/98 (now called the Facade Inspection & Safety Program, or FISP), which requires buildings taller than six stories to have their facades inspected for unsafe conditions every five years. Less well known is Local Law 37/08, which requires owners with retaining walls 10 feet or taller that front a public right of way to have those walls inspected by a design professional every five years to ensure they are maintained in a safe condition.
Similar to FISP, owners must file an inspection report with the Department of Buildings stating the retaining wall condition as safe, unsafe, or safe with repair and/or engineering monitoring. Property owners with unsafe retaining walls are issued an ECB violation and face fines of up to $1,200.
New DOB Rule
The DOB recently adopted a rule that specifies which elements of a retaining wall must be assessed, what steps to take if there are unsafe conditions, what information the inspection report must include, and more.
In RAND’s latest Ask the Engineer column, we discuss the hazards facing retaining walls as well as how to keep them from becoming unsafe, including
- Drainage problems
- Load changes
- Rails and fences
- Repair and replacement
- Ongoing maintenance
We also include information on the DOB’s No-Penalty Retaining Wall Inspection Program, offered every spring.
For more on retaining walls, read the full article and send us your questions or comments at info@nullrandpc.com, or call us at 212-675-8844. Don't wait until those walls come tumblin' down.
