peoples-api-demos

NYC Housing Policy Analysis — Project Ontology

This document was produced using Claude, an AI assistant by Anthropic. Content should be reviewed for accuracy.

1. Dataset Inventory

# Dataset File(s) Rows Columns Time Span Grain
1 NYC 311 Service Requests NYC311-2010-to-20260301.csv (25 GB) ~42.96M 44 2010 – Mar 2026 Individual complaint
2 Housing Database (DCP) HousingDB_post2010.csv (46 MB) ~81.7K 63 Post-2010 jobs DOB job application
3 PLUTO Primary_Land_Use_Tax_Lot_Output_(PLUTO)_20260206.csv (411 MB) ~858K 101 Snapshot (Feb 2026) Tax lot (BBL)
4 Furman Center SHD — BBL Analysis FC_SHD_bbl_analysis_2025-05-13.csv (5.6 MB) ~13.9K 126 As of May 2025 Subsidized tax lot
5 Furman Center SHD — Subsidy Analysis FC_SHD_subsidy_analysis_2025-05-13.csv (6.1 MB) ~14.1K 124 As of May 2025 Individual subsidy record
6 StreetEasy Master Report 44 zip archives in StreetEasy_Master_Report/ ~198 rows each ~195 month-columns Jan 2010 – Feb 2026 Area × month (wide format)

Data Dictionaries (xlsx): Housing_Database_Data_Dictionary.xlsx, FC_SHD_bbl_analysis_data_dictionary_2025-05-13.xlsx, FC_SHD_subsidy_analysis_data_dictionary_2025-05-13.xlsx

2. Entity Definitions

2.1 Tax Lot (BBL)

The fundamental spatial unit across most datasets. A Borough-Block-Lot (BBL) is a 10-digit identifier (1-digit borough + 5-digit block + 4-digit lot) assigned by the NYC Department of Finance. Present in: PLUTO (BBL), HousingDB (BBL), Furman Center BBL (bbl), 311 (BBL).

2.2 Building (BIN)

A Building Identification Number uniquely identifies a structure. Present in: HousingDB (BIN). A single BBL may contain multiple BINs.

2.3 DOB Job Application

A permit application filed with the Department of Buildings for new construction, alteration, or demolition. The primary entity in HousingDB, keyed by Job_Number.

2.4 311 Service Request

An individual complaint or service request filed through the NYC 311 system, keyed by Unique Key. Contains complaint type, location (address, BBL, lat/lon), timestamps, and resolution info.

2.5 Subsidized Housing Property

A residential property receiving one or more government subsidies. The Furman Center BBL file is at the property level; the Subsidy file has one row per subsidy-property pair (a single BBL may have multiple active subsidies).

2.6 StreetEasy Market Area

A named geographic area (neighborhood, submarket, borough, or citywide) for which StreetEasy reports monthly market metrics. Areas are identified by areaName, Borough, and areaType.

3. Key Attributes by Dataset

3.1 NYC 311 Service Requests (44 columns)

Sample agencies: HPD, DOB, NYPD, DEP, DSNY, DOT, DOHMH, DPR, DCA, DHS, DFTA, TLC, EDC Sample complaint types (housing-relevant): HEAT/HOT WATER, DOOR/WINDOW, ELECTRIC, ELEVATOR, FLOORING/STAIRS, GENERAL, Boilers, Building/Use, General Construction/Plumbing, Asbestos, Lead, Noise, Dirty Conditions

3.2 Housing Database — DCP (63 columns)

3.3 PLUTO (101 columns)

3.4 Furman Center — BBL Analysis (126 columns)

3.5 Furman Center — Subsidy Analysis (124 columns)

Same structure as BBL Analysis but keyed by fc_subsidy_id (one row per subsidy). Adds: agency_name, subsidy_name, sub_subsidy_name, project_name, start_date, end_date, tenure, preservation, program, reac_score, reac_date, tot_bbls, tot_buildings, tot_units

3.6 StreetEasy Master Report (44 files)

Sales Market Metrics (by property type: All, Condo, Coop, Sfr):

Rental Market Metrics (by bedroom count: All, Studio, OneBd, TwoBd, ThreePlusBd):

Structure: Wide-format time series. Columns: areaName, Borough, areaType, then one column per month (YYYY-MM). Index files (priceIndex, rentalIndex) have columns: month, Brooklyn, Manhattan, NYC, Queens.

Geographic levels (areaType): city, borough, submarket, neighborhood (~198 areas) Boroughs: Manhattan, Brooklyn, Queens, Bronx, Staten Island

4. Join Keys & Linkage Map

                    ┌──────────────┐
                    │   BBL (10d)  │  ← Primary spatial join key
                    └──────┬───────┘
           ┌───────────────┼───────────────────┐
           │               │                   │
     ┌─────▼─────┐   ┌────▼─────┐    ┌────────▼────────┐
     │   PLUTO   │   │ HousingDB│    │ Furman Ctr (BBL) │
     │  858K lots │   │ 81K jobs │    │  13.9K subsidized│
     └─────┬─────┘   └────┬─────┘    └────────┬────────┘
           │               │                   │
           │          BIN ─┘         fc_subsidy_id
           │                                   │
           │                          ┌────────▼────────┐
           │                          │ Furman Ctr (Sub) │
           │                          │ 14.1K subsidies  │
           │                          └─────────────────┘
           │
     ┌─────▼──────────┐
     │   NYC 311       │
     │  43M complaints │  ← joins on BBL (28% populated),
     │                 │    or Incident Zip / Borough /
     └────────────────┘    Community Board / Council Dist

StreetEasy does not share BBL. Linkage to lot-level data requires geographic bridging:

StreetEasy areaType Bridge to lot-level data via
borough PLUTO borocode, 311 Borough
neighborhood Manual or fuzzy mapping to NTA / community district names
submarket Manual mapping (StreetEasy-proprietary groupings)
city N/A (citywide)

Cross-dataset join keys summary:

Key PLUTO HousingDB FC-BBL FC-Sub 311 StreetEasy
BBL ✅ PK ✅ ✅ PK ✅ (ref_bbl) ✅ (partial) —
BIN — ✅ — — — —
Borough ✅ ✅ ✅ ✅ ✅ ✅
Community District ✅ ✅ ✅ ✅ ✅ —
Council District ✅ ✅ ✅ ✅ ✅ —
Census Tract ✅ ✅ ✅ ✅ — —
NTA — ✅ — — — ~ (neighborhood)
Zip Code ✅ — — — ✅ —
Lat/Lon ✅ ✅ ✅ — ✅ —

5. Temporal Coverage

Dataset Start End Granularity
NYC 311 2010 Mar 2026 Daily (Created/Closed dates)
HousingDB Post-2010 Current vintage Event dates (Filed, Permit, Complete)
PLUTO Snapshot Feb 2026 Point-in-time
Furman Center Varies by subsidy May 2025 vintage Subsidy start/end dates
StreetEasy Jan 2010 Feb 2026 Monthly

6. Thematic Domains & Analytical Dimensions

6.1 Housing Supply Pipeline

Primary source: HousingDB Key measures: ClassANet (net new units), Job_Type, Job_Status, CompltYear, PermitYear Supports: Tracking new construction, alterations, demolitions; net unit change by geography and year

6.2 Land Use & Zoning Capacity

Primary source: PLUTO Key measures: landuse, bldgclass, zonedist, builtfar vs residfar/commfar, lotarea, bldgarea, unitsres Supports: Zoning analysis, underbuilt lot identification, land use classification

6.3 Subsidized & Affordable Housing

Primary sources: Furman Center BBL + Subsidy Key measures: Subsidy programs (28 types), start/end dates, res_units, income targeting, REAC scores, tenure, preservation vs. new construction Supports: Subsidy expiration risk analysis, portfolio composition, geographic concentration, physical condition (REAC)

6.4 Housing Conditions & Complaints

Primary source: NYC 311 Key measures: Complaint type (HEAT/HOT WATER, etc.), volume trends, resolution time, geographic clustering Supports: Identifying problem buildings/areas, correlating complaints with subsidized housing, seasonal patterns

6.5 Market Dynamics

Primary source: StreetEasy Key measures: Median prices/rents, inventory levels, days on market, price cuts, sale/list ratios, price/rental indices Supports: Price trend analysis by neighborhood/borough, market tightness indicators, affordability benchmarking

6.6 Property Characteristics & Valuation

Primary source: PLUTO Key measures: assessland, assesstot, exempttot, yearbuilt, ownername, ownertype Supports: Tax base analysis, age of housing stock, ownership patterns

6.7 Flood Risk

Primary sources: PLUTO (firm07_flag, pfirm15_flag), HousingDB (PL_FIRM07, PL_PFIRM15) Supports: Identifying housing in flood zones, climate risk overlay with subsidized housing

7. Geographic Hierarchy

NYC (city)
 └── Borough (5)
      └── Community District (~59)
           └── Neighborhood / NTA (~262)
                └── Census Tract (~2,168)
                     └── Census Block
                          └── Tax Lot (BBL, ~858K)

Additional administrative overlays: Council District, Police Precinct, School District, Fire Company, Sanitation District, Health Area, Zip Code.

StreetEasy uses its own geography: city → borough → submarket → neighborhood (~198 areas total).

8. Subsidy Program Taxonomy (Furman Center)

By category:

Data sources: DOF, HCR-LIHTC, HPD, HUD Contracts, HUD Financing, HUD-LIHTC, Mitchell-Lama, NYCHA

9. Known Data Considerations

  1. 311 BBL coverage: The BBL field in 311 data is not universally populated — geographic joins will have partial coverage; spatial joins via lat/lon can supplement.
  2. StreetEasy geographic bridging: StreetEasy neighborhoods don’t map 1:1 to official NTAs or community districts. A crosswalk or fuzzy mapping will be needed for lot-level integration.
  3. StreetEasy wide format: All StreetEasy CSVs use wide format (one column per month). They will need to be unpivoted/melted for time-series analysis.
  4. PLUTO is a snapshot: PLUTO represents current conditions only. Historical changes must be inferred from HousingDB or prior PLUTO vintages.
  5. Furman Center subsidy dates: Some subsidy end dates may be missing or represent regulatory expiration rather than actual exit from affordability.
  6. 311 file size: At 25 GB and ~43M rows, the 311 file will require chunked processing or sampling for exploratory analysis.
  7. HousingDB includes inactive jobs: The Job_Status field (and the noted Job_Inactv flag) should be used to filter to active/completed projects for pipeline analysis.

This document was produced using Claude, an AI assistant by Anthropic. Content should be reviewed for accuracy.

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