Methodology
Where the Data Comes From
Building profiles are generated by pulling millions of live and historical records directly from the official NYC Open Data portal. The data is aggregated from the following city agencies:
- Department of City Planning: For baseline building specs (year built, unit counts).
- Department of Investigation: For executed residential marshals evictions.
- Housing Preservation and Development: For maintenance code violations, active housing court litigations, and the annual bedbug registry.
- Department of Buildings: For structural, safety, and construction violations.
- Office of Technology and Innovation: For tenant-reported service requests over the last 12 months.
The Risk Score Algorithm
1 Weighted Hazard Points
The algorithm assigns penalty points based on severity and recency:
-
Severe Safety Hazards
Active housing court lawsuits against the landlord carry the highest penalty. Heavy weight is also applied to executed evictions from the last five years, open hazardous violations (e.g., lack of heat, structural damage), and confirmed bedbug infestations. -
Chronic Neglect & Administrative Flags
Hiding or failing to file annual bedbug reports, historical evictions, and minor maintenance issues. -
Quality of Life Disruptions
Tenant 311 complaints specifically related to pests, heat, plumbing, and power outages from the last 12 months, as well as recently closed violations.
2 Per-Unit Normalization & Cohorts
The total penalty score is divided by the building's total number of residential units. This calculates the concentrated risk per apartment, preventing large buildings from being penalized simply for being large.
To ensure fair comparisons, the building is then grouped and evaluated strictly against peers of a similar size:
Small Home
1-2 units
Walk-up
3-10 units
Mid-Size
11-50 units
Large Complex
51+ units
3 Grading on a Curve
A building's normalized hazard score is ranked strictly against other buildings in its cohort. The resulting percentile dictates the letter grade:
A
Top 20%
B
Next 20%
C
Middle 20%
D
Lower 20%
F
Bottom 20%