Retaining walls are among the least visible — and most overlooked — structural elements subject to mandatory NYC DOB inspection requirements.

What Triggers the Requirement

The inspection requirement applies when two conditions are both met: the retaining wall is ten feet or more in height at any point along its length, and the wall fronts on a public right-of-way — meaning it abuts a public street, sidewalk, alley, or other public space that the public can freely approach. Height is measured as the vertical distance from the ground surface above the toe of the wall to the top of the wall, stem, or step for tiered walls, including any parapets or fencing intended for retaining material.

Walls that are shared between neighboring properties may be inspected by a single QRWI retained jointly by the owners, but each property owner must still pay their applicable filing fees and a separate acceptable report must be filed for each property.

Filing Windows by Borough

Cycle 3 runs from January 1, 2024 through December 31, 2028. Unlike FISP, which staggers deadlines by block number, retaining wall inspections are staggered by borough — each borough has a one-year window within the five-year cycle. The report must be filed with the DOB within 60 days of completing the inspection, and no later than the end of the applicable borough's filing window.

Penalties Now Apply Beginning with Cycle 3

A significant change took effect with Cycle 3: beginning with this cycle, owners who fail to file an acceptable retaining wall compliance report by the due date are subject to the civil penalties listed in 1 RCNY §103-09. In prior cycles, the penalty framework was not enforced in the same way. Property owners who missed the Bronx or Manhattan windows without filing should consult directly with the DOB or a licensed professional regarding their options.

2025 Rule Amendments

Effective March 23, 2025, the DOB implemented amendments to 1 RCNY §103-09. Among the notable changes: QRWIs no longer need prior DOB approval before commencing inspections — they must instead follow accepted standards of care and design an inspection program that allows for a complete review of the wall. Updated documentation standards now require that unsafe or repair-required conditions be supported by photographs and a mapped layout. Report labeling and follow-up filing requirements were also clarified.

Qualified Retaining Wall Inspectors (QRWIs)

Retaining wall inspections under 1 RCNY §103-09 may only be performed by a Qualified Retaining Wall Inspector — a New York State licensed Professional Engineer designated by the NYC DOB as a QRWI. Only a QRWI can file the TR16 report with the Department.

QRWI Qualifications

QRWIs must be New York State licensed Professional Engineers in good standing with both the New York State Education Department and the NYC Department of Buildings. They must maintain the insurance coverage required under 1 RCNY §101-07, copies of which must be made available to the DOB upon request. Professional Engineers, individuals with a bachelor's degree in engineering and three years of relevant experience, or individuals with five years of relevant experience may be delegated to perform selected inspection tasks under a QRWI's direct supervision — but the QRWI must personally perform the final inspection and sign the report.

What the Critical Examination Involves

Before performing the critical examination, the QRWI must review the most recent prior report, any available previous reports, structural design or repair drawings, and any open violations. A drive-by inspection is not acceptable — the QRWI must examine the full length of the wall from both sides. The inspection program must account for retaining wall type, cross-sections, architectural finishes, drainage conditions, selective probes, wall dimensions, and all surrounding elements that affect the wall's stability.

What the Retaining Wall Assessment Covers

The critical examination must permit a complete review of the wall's structural condition and all elements that affect its performance and stability. The following areas are assessed as part of the QRWI's inspection program.

• Overall wall stability and alignment
• Structural cracking — horizontal, diagonal, and through-wall
• Tilting, leaning, and displacement
• Bulging and outward movement
• Masonry condition — stonework, brick, concrete block
• Concrete spalling and surface deterioration
• Mortar joint condition and repointing needs
• Wire basket and gabion integrity
• Drainage system condition and function
• Water infiltration and saturation signs
• Vegetation growth and root intrusion
• Soil erosion above and below the wall
• Adjacent slope and embankment conditions
• Footing and toe condition (where accessible)
• Parapets and fencing attached to the wall
• Wall dimensions and cross-section measurements

TR16 Report Requirements

The QRWI must file a written Report of Critical Examination — designated TR16 — with the DOB within 60 days of completing the inspection. Reports are submitted as PDF files via email to LL37RetainingWalls@buildings.nyc.gov along with a Retaining Wall Inspection Report Program Intake Form (RWIP6) listing each wall submitted. DVD, CD, flash drive, and paper reports are not accepted.

The TR16 report must include: the property address and Block and Lot number; a description of the wall's construction type, materials, height, and dimensions; a cross-section drawing of the retaining wall; detailed structural engineering calculations; documented conditions with photographs and mapped layout (required as of the March 2025 amendments for walls rated SREM or Unsafe); the final wall rating; and a copy submitted to the building owner. A separate acceptable report must be prepared and filed for each property with a qualifying retaining wall.

Wall Ratings Under 1 RCNY §103-09

Following the critical examination, the QRWI assigns one of four condition ratings to the retaining wall. Each rating carries distinct compliance obligations for the property owner.

Steps for Retaining Wall Compliance

The following outlines the standard path for meeting the DOB's retaining wall inspection requirement within the applicable borough's Cycle 3 filing window.

Common Retaining Wall Conditions in NYC

Retaining walls in New York City's built environment face unique stresses — saturated soil, freeze-thaw cycling, hydrostatic pressure, root intrusion from adjacent urban plantings, and vibration from nearby transit infrastructure. Many of the city's retaining walls were constructed decades ago with materials and drainage details that require ongoing attention.

Drainage Failure

Inadequate or blocked drainage is the leading contributor to retaining wall deterioration in urban environments. When water cannot drain freely from the soil behind the wall, hydrostatic pressure builds against the wall face — increasing lateral load beyond the wall's design capacity and accelerating cracking, leaning, and eventual failure. Drainage inspections, outlet cleaning, and repair or replacement of drainage systems are among the most common interventions following retaining wall assessments.

Masonry Cracking and Displacement

Horizontal cracks near the base of a masonry retaining wall, diagonal cracks from corners, or cracks with displacement — where one side of the crack has shifted relative to the other — are structural red flags requiring engineering evaluation. Vertical cracking in concrete walls and spalling of the concrete face are common in older walls and may indicate rebar corrosion or freeze-thaw damage within the wall section.

Tilting and Leaning

Walls that have rotated or displaced outward from their original position are exhibiting movement that indicates the forces being retained exceed the wall's passive resistance. Even small amounts of measurable lean — particularly when progressive — warrant engineering monitoring and may require structural intervention, anchoring, or buttressing to stabilize.

Vegetation and Root Intrusion

Trees and substantial shrubs growing adjacent to or from within retaining wall joints introduce root pressure that can dislodge masonry, crack concrete, and undermine mortar joints over time. Vegetation management is often a recommended maintenance measure following inspection, and repointing or masonry repair may be required in affected areas.

Penalties for Non-Compliance

Beginning with Cycle 3, the DOB now actively enforces civil penalties for failure to file an acceptable retaining wall compliance report by the applicable borough deadline. Penalty amounts are set under 1 RCNY §103-09 and are assessed for each reporting period in which a required report is not filed.

The original site penalty structure specified in 1 RCNY §103-09 includes an initial fine of $1,000 for failure to file, with an additional $250 per month the report remains unfiled. Additional fines may be imposed for failure to complete required repairs within the timeframes specified in a filed report. For Unsafe conditions, failure to install required public protection or complete repairs within the 365-day window may result in further enforcement action.

Late Filing After the Borough Window Closes

Property owners whose borough filing window has already closed — Bronx (2024) and Manhattan (2025) — without a filed report should not delay further. Penalties accrue from the deadline date and the DOB has posted detailed penalty payment and waiver request instructions. Questions regarding specific property status and penalty exposure can be directed to LretainingWalls@buildings.nyc.gov.

Post & Lintel Retaining Wall Services

Post & Lintel supports property owners through every phase of the retaining wall inspection and compliance process. Field observations and documentation may be performed by trained personnel; all regulated evaluations, wall ratings, and DOB filings are handled by appropriately licensed professionals.

• Applicability and height verification
• Borough sub-cycle and deadline confirmation
• Prior report and violation record review
• QRWI engagement and coordination
• Critical examination coordination
• Visual and structural condition documentation
• Cracking and displacement observation
• Drainage condition assessment support
• Photographic and mapped documentation
• TR16 report preparation and DOB filing
• RWIP6 intake form submission
• SMR repair scope and scheduling
• SREM engineering monitoring coordination
• Unsafe condition response support
• Repair permit coordination
• Masonry and drainage repair coordination
• Amended TR16 filing upon repair completion
• Shared-wall multi-owner coordination

Who We Work With

Retaining walls subject to inspection requirements are found across a wide range of property types in New York City — particularly in areas with significant grade changes, transportation infrastructure, and older urban development patterns.

Frequently Asked Questions