How Building Scores Work | NYC Apartment Rating Methodology

Scoring 2.0

Dec 17, 2024

Major fairness improvements to ensure buildings are ranked equitably

Tiered Litigious Tenant Discount

When 90%+ of violations come from one unit, discounts now vary by severity: 15% for Class C (serious), 30% for B, 50% for A (minor).

Conditional Age Penalty

Old buildings only penalized if they show maintenance issues. Well-maintained 100-year-old buildings get no penalty.

Serial 311 Complainer Detection

If 80%+ of 311 complaints are the same type (e.g., all noise), 30% discount applied. One sensitive neighbor shouldn't tank scores.

Stronger Stale Violation Decay

Very old 'open' violations (10-15yr: 30%, 15+yr: 10%) are likely data issues, not real problems.

Hybrid Responsiveness Scoring

50% absolute thresholds + 50% relative to borough. A landlord fixing issues in 21 days scores well in ANY borough.

Renovation Clean Slate

Buildings with major renovations (NB/A1 permits) in last 3 years get 50% discount on historical violations.

Small Building Benefit of Doubt

Zero violations in small buildings (≤8 units) or condos gets 50-70% less 'too perfect' skepticism.

Track Record Weight Reduced

Reduced from 2.5× to 2.0× to avoid double-counting violations already penalized in Safety/Maintenance.

TL;DR: Buildings are now scored more fairly — well-maintained old buildings, small owner-occupied properties, and buildings with one complainy tenant or neighbor won't be unfairly penalized. Serious issues still get flagged strongly.

The Algorithm

Weighted composite scoring

Final Score =

Σ(Category_i × Weight_i)

÷

Σ Weights

Σ(Category_i × Weight_i) ÷ Σ Weights

Adjusted for age, size, violation caps, and difficulty factors

3.5×

Safety & Health

Highest priority

3.0×

Maintenance

Daily quality

2.5×

Risk Factors

Freeze, Toxic

2.0×

Compliance

Paperwork & filings

Core Principles

Time Decay

3%

impact after 5yr

Old fixed issues fade over time. A violation fixed 5+ years ago has only 3% of its original impact. Open violations 15+ years old are likely stale data.

Open vs Closed

10×

open violation weight

Open violations are 5-10x more impactful than closed ones. Very old 'open' violations (10+ years) are discounted as likely stale data.

Per-Unit Normalization

÷

units for fairness

10 violations in a 100-unit building is better than 10 in a 5-unit building. We normalize fairly.

Max Score: 99.5

99.5

maximum possible

No building scores 100. We cap scores because unreported issues and uncertainty always exist.

Violation Existence Penalty

50

max with 100+ violations

Having violations at all caps your maximum score. 50+ violations caps at 60, 100+ caps at 50.

"Too Perfect" Skepticism

70%

less skepticism for small

Zero violations might mean under-inspection. BUT: small buildings (≤8 units) and condos get benefit of the doubt.

Conditional Age Penalty

0

if well-maintained

Old buildings only penalized if they show maintenance issues. Well-maintained 100-year-old buildings get no penalty.

Score Compression

90+

compression zone

Scores above 90 are compressed to spread distribution. Reaching 95+ requires excellence across all categories.

Litigious Tenant Detection

15-50%

class-specific discount

If 90%+ of violations come from one unit, discount varies by severity: 15% for Class C, 30% for B, 50% for A (minor issues).

Renovation Clean Slate

50%

history discount

Buildings with major renovations (NB/A1 permits) in last 3 years get 50% discount on historical violations. Open issues still count.

Hybrid Responsiveness

50/50

absolute + relative

50% absolute thresholds + 50% relative to borough. A landlord who fixes issues in 21 days scores well regardless of borough.

Serial 311 Complainer

30%

discount applied

If 80%+ of 311 complaints are the same type (e.g., all noise), the building gets 30% discount. One sensitive neighbor shouldn't tank scores.

Paperwork vs. Actual Issues

We distinguish between administrative failures and real hazards

Not all violations are equal!

A "Bedbug Violation" might just mean the landlord forgot to file paperwork — not that there are actual bedbugs. We carefully distinguish between paperwork/filing failures (administrative) and actual physical hazards (safety risks).

📋

Paperwork Violations

Tracked in Compliance score, not Safety/Pest scores

•"File annual bedbug report" — just paperwork, no actual bedbugs
•"Post lead paint notice" — notice requirement, not lead hazard
•"Post smoke detector notice" — posting requirement only
•"Owner failed to file registration" — unregistered building

⚠️

Actual Hazards

Full impact on relevant scores (Pest, Toxic, Safety)

•"Abate the nuisance consisting of bedbugs" — actual infestation!
•"Remedy lead paint hazard" — real lead exposure risk
•"Provide missing smoke detector" — actual safety issue
•"Mice/rats evidence observed" — real pest problem

Why this matters: Paperwork violations still count against the building (they show landlord negligence), but they're tracked in the Compliance score — not inflating Pest or Safety scores. This prevents a building from appearing dangerous when it's just administratively messy.

Grade Thresholds

A

90-99.5

B

80-89

C

70-79

D

60-69

F

0-59

The worst buildings score as low as 12-15. The best can reach 99.5.

The NYC Reality

What scores actually mean in context

Most NYC buildings are good — but 311 data reveals more.

84.7% of buildings score 80+ — the majority of NYC buildings are well-maintained. With 311 complaint data now factored in, we can see more nuance in building quality. Our scoring helps you avoid problematic buildings that official violations alone might miss.

Score Distribution Across 314,575 Buildings

90-100

52.8%

166,130

80-89

31.9%

100,446

70-79

5.3%

16,660

60-69

1.6%

5,185

50-59

0.5%

1,621

40-49

0%

151

30-39

3.5%

11,026

20-29

4.2%

13,356

Borough Rankings (by mean score)

1

Queens

98,417 buildings

87.1

2

Staten Island

18,275 buildings

87

3

Brooklyn

128,097 buildings

83.5

4

Manhattan

29,282 buildings

79.2

5

Bronx

40,504 buildings

77.6

Top 10 Neighborhoods

#1Long Island CityQueens1391.7

#2Battery Park CityManhattan2791.3

#3FlatironManhattan6591.3

#4Shore AcresStaten Island1191.1

#5NeponsitQueens17091.1

#6Douglas ManorQueens3690.8

#7Hollis HillsQueens4490.8

#8Lighthouse HillStaten Island4590.5

#9Todt HillStaten Island3190.5

#10Queensboro HillQueens89290.5

Counts shown are the number of buildings in each neighborhood sample.

Bottom 10 Neighborhoods (where our tool matters most)

#339ManhattanvilleManhattan9659.6

#340Washington HeightsManhattan78858.2

#341WilliamsbridgeBronx24257.5

#342Hudson HeightsManhattan60356.7

#343InwoodManhattan35055

#344West HarlemManhattan23954.1

#345West ConcourseBronx6047.6

#346ConcourseBronx447.5

#347Fort GeorgeManhattan23245.9

#348RoxburyQueens123.3

A few observations

Most scores cluster high: 52.8% of buildings are in the 90–100 band, and 84.7% are 80+. That’s partly by design — the scoring is meant to highlight the outliers you want to avoid.
Queens & Staten Island lead on average (with very large coverage in Queens), while Manhattan and the Bronx have lower means in this dataset.
Neighborhood “top/bottom” lists can be sample-size sensitive: several top neighborhoods have ~10–60 buildings, and the single-building Roxbury result is an extreme outlier. Treat these as directional, not definitive.

Bottom line: In NYC, bad buildings are the exception, not the rule. StreetSmart exists to help you spot the exceptions before you sign a lease.

Time Decay Function

How closed violation impact fades over time

0-6 months

100%

Full impact (recently fixed)

6-12 months

85%

Still recent

1-2 years

60%

Moderate impact

2-3 years

35%

Reduced impact

3-5 years

15%

Minimal impact

5+ years

3%

Almost no impact

Note: Open violations are treated as current issues and generally carry full impact. However, to guard against stale “open” records that can persist for many years, very old open violations are discounted slightly.