From 02-zoning-analysis
Analyzes zoning envelope rules for NYC lots using PLUTO data and Zoning Resolution. Input address, BBL, or BIN to fetch zoning districts, FAR limits, lot area, and polygon geometry.
npx claudepluginhub alpacalabsllc/skills-for-architects --plugin 02-zoning-analysisThis skill is limited to using the following tools:
Analyze building envelope rules for any lot in New York City using the PLUTO database (NYC Open Data) and the NYC Zoning Resolution.
Analyzes zoning regulations and generates form-based codes including Euclidean, performance, and transect-based systems. Useful for setbacks, height limits, FAR, use permissions, masterplans, and design-to-regulation translation.
Check if a NYC building is landmarked or in a historic district using LPC Individual Landmarks and PLUTO datasets. Accepts address, BBL, or BIN.
Analyzes zoning envelope rules for urban/rural lots in Maldonado, Uruguay from ArcGIS GIS JSON data and TONE regulations. Compares individual, party wall, and unified development scenarios.
Share bugs, ideas, or general feedback.
Analyze building envelope rules for any lot in New York City using the PLUTO database (NYC Open Data) and the NYC Zoning Resolution.
Accept one of the following identifiers:
Normalize to BBL format: [borough 1 digit][block 5 digits][lot 4 digits]
Borough codes:
| Code | Borough |
|---|---|
| 1 | Manhattan |
| 2 | Bronx |
| 3 | Brooklyn |
| 4 | Queens |
| 5 | Staten Island |
Fetch lot data from two NYC APIs in parallel:
Endpoint: https://data.cityofnewyork.us/resource/64uk-42ks.json
Query by BBL:
https://data.cityofnewyork.us/resource/64uk-42ks.json?bbl=XXXXXXXXXX
Query by address (fallback):
https://data.cityofnewyork.us/resource/64uk-42ks.json?$where=address='123 MAIN STREET' AND zipcode='10001'
No authentication required for basic queries.
Read zoning-rules/pluto-fields.md for the full field reference.
Extract these key fields:
bbl — Borough-Block-Lotaddress, zipcode — street addresszonedist1 through zonedist4 — zoning district(s)overlay1, overlay2 — commercial overlay districtsspdist1, spdist2, spdist3 — special purpose districtsltdheight — limited height districtsplitzone — Y if lot is split across zoneslotarea — lot area in SFbldgarea — total building area in SFbuiltfar — as-built FARresidfar — maximum residential FARcommfar — maximum commercial FARfacilfar — maximum community facility FARnumfloors — existing number of floorslanduse — current land use categoryzonemap — zoning map numberlandmark — landmark designationhistdist — historic district nameborocode, block, lot — parsed BBL componentsEndpoint: https://a841-dotweb01.nyc.gov/arcgis/rest/services/GAZETTEER/MapPLUTO/MapServer/0/query
Query by BBL:
https://a841-dotweb01.nyc.gov/arcgis/rest/services/GAZETTEER/MapPLUTO/MapServer/0/query?where=BBL='XXXXXXXXXX'&outFields=BBL&f=json&outSR=4326
This returns the exact tax lot polygon in WGS84 (lat/lon). No authentication required.
Convert to local feet:
features[0].geometry.rings[0] coordinate array (pairs of [lon, lat])cos(lat)x_ft = (lon - lon_min) × 111320 × cos(lat) × 3.28084y_ft = (lat - lat_min) × 111320 × 3.28084LOT_POLY array of [x, y] pairs in feetlotarea (expect ±5% due to projection)Always use the real polygon for the 3D envelope viewer. Never fall back to a lotfront × lotdepth rectangle when polygon data is available.
If either query returns no results, inform the user and ask them to verify the address or BBL.
Map the zonedist1 value to its district type:
| Prefix | Type | Normativa File |
|---|---|---|
| R | Residential | zoning-rules/residential.md |
| C | Commercial | zoning-rules/commercial.md |
| M | Manufacturing | zoning-rules/manufacturing.md |
Check for:
splitzone = Y): Analyze each zonedist1–zonedist4 separately. Pro-rate FAR by estimated area in each zone if lot dimensions are available, otherwise present both sets of controls.zoning-rules/contextual-districts.md.overlay1/overlay2): If present (e.g., C1-4, C2-5), load zoning-rules/commercial.md for overlay rules.spdist1–spdist3): If present, load zoning-rules/special-districts.md.ltdheight): Note the height cap.State your district identification and reasoning clearly.
Read the relevant regulation files from the skill's zoning-rules/ directory:
zoning-rules/overview.md — system primerresidential.md, commercial.md, or manufacturing.mdzoning-rules/contextual-districts.md — if district has A/B/D/X suffixzoning-rules/special-districts.md — if spdist1–spdist3 are populatedzoning-rules/use-groups.md — for permitted use analysiszoning-rules/parking.md — for parking requirementszoning-rules/city-of-yes.md — for recent reform impactsCalculate the building envelope for the lot:
Floor Area Ratio (FAR):
residfar or district table)commfar or district table)facilfar or district table)Building Height:
Setbacks:
Lot Coverage:
Yards:
Apply contextual district rules when suffix is present — these override standard height/setback rules with mandatory streetwall, base height, and setback requirements.
Layer additional regulations on top of base district controls:
Commercial overlays (C1-1 through C2-5 in residential districts):
Special purpose districts:
zoning-rules/special-districts.md for the specific districtInclusionary Housing:
Landmark / Historic District:
landmark or histdist is populated, note that Landmarks Preservation Commission (LPC) review is requiredCity of Yes reforms:
zoning-rules/city-of-yes.md for applicable changesUse the output format below to present a structured, comprehensive analysis.
Write the analysis to a markdown file in the current working directory:
zoning-analysis-[address-slug].mdzoning-analysis-123-main-st-brooklyn.md# Zoning Analysis — [Address], [Borough]
## Lot Summary
| Parameter | Value |
|-----------|-------|
| BBL | X-XXXXX-XXXX |
| Address | ... |
| Borough | ... |
| Lot Area | ... SF |
| Current Building Area | ... SF |
| Current FAR (built) | ... |
| Current Use | ... |
| Zoning Map | ... |
## Zoning Classification
| Parameter | Value |
|-----------|-------|
| Primary District | ... |
| Secondary District(s) | ... (or None) |
| Commercial Overlay | ... (or None) |
| Special District | ... (or None) |
| Limited Height | ... (or None) |
| Contextual | Yes/No |
| Split Zone | Yes/No |
| Landmark | ... (or None) |
| Historic District | ... (or None) |
## Bulk Parameters
### Floor Area
| Use | Max FAR | Max Floor Area (SF) |
|-----|---------|---------------------|
| Residential | ... | ... |
| Commercial | ... | ... |
| Community Facility | ... | ... |
### Height & Setback
| Parameter | Value |
|-----------|-------|
| Max Building Height | ... ft |
| Base Height (min–max) | ... ft (contextual only) |
| Sky Exposure Plane | starts at ... ft, ratio .../1 |
| Street Wall | required/not required |
### Yards & Coverage
| Parameter | Value |
|-----------|-------|
| Front Yard | ... ft |
| Rear Yard | ... ft |
| Side Yards | ... |
| Max Lot Coverage | ...% |
| Open Space Ratio | ... (if applicable) |
## Permitted Uses
Key permitted uses by Use Group for this district. Highlight the most relevant:
- Residential: ...
- Commercial: ...
- Community Facility: ...
- Manufacturing: ... (if applicable)
## Parking Requirements
Based on current rules (post-City of Yes where applicable):
| Use | Requirement |
|-----|-------------|
| Residential | ... |
| Commercial | ... |
| Other | ... |
## Bonuses & Incentives
- Inclusionary Housing bonus: ...
- UAP (City of Yes): ...
- Other applicable bonuses: ...
## Restrictions & Special Conditions
- Landmark/LPC review: ...
- Special district requirements: ...
- Environmental: ...
- Other: ...
## Development Potential
| Scenario | FAR | Floor Area (SF) | Est. Floors |
|----------|-----|------------------|-------------|
| As-of-right residential | ... | ... | ... |
| As-of-right commercial | ... | ... | ... |
| With IH bonus | ... | ... | ... |
| With UAP bonus | ... | ... | ... |
## Buildable Envelope
### Plan View
ASCII diagram showing the lot boundary with setbacks and buildable zone. Orient with the primary street frontage at the bottom. Label dimensions, setback distances, and buildable area. Use PLUTO lot dimensions (lotfront, lotdepth) where available.
Example:
← 170 ft →
┌────────────────────────────┐
│ 20 ft rear yard │ ↑
│ ┌──────────────────────┐ │ |
│ │ │ │ |
│ │ BUILDABLE ZONE │ │ 130 ft
│ │ ~150 ft × 170 ft │ │ |
│ │ │ │ |
│ │ │ │ |
│ └──────────────────────┘ │ ↓
└────────────────────────────┘
HUDSON ST (wide street)
← no front setback →
### Section View
ASCII cross-section showing the height and setback envelope from street level. Include base height, setback, sky exposure plane, and maximum height. For contextual districts, show the mandatory streetwall height range.
Example:
290 ft ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ max height │ ╱ │ ╱ sky exposure │ ╱ plane (5.6:1) │ ╱ 85 ft ├──────┤ ← setback line │ │ │ │ base / streetwall │ │ (60–85 ft) │ │ ───────┴──────┴──────────────── street HUDSON ST (wide)
Adapt both diagrams to the specific lot. Use actual dimensions and controls from the analysis. If the lot is irregular or split-zone, note the complexity and simplify where needed.
## Envelope Data
Machine-readable data for `/zoning-envelope`. Include the exact lot polygon from Step 2b (MapPLUTO ArcGIS) converted to local feet, plus all computed envelope parameters.
```json
{
"lot_poly": [[x, y], ...],
"unit": "ft",
"setbacks": { "front": 0, "rear": 20, "lateral1": 0, "lateral2": 0 },
"volumes": [
{ "type": "base", "inset": 20, "h_bottom": 0, "h_top": 85, "label": "base (streetwall)" },
{ "type": "tower", "inset": 10, "h_bottom": 85, "h_top": 290, "label": "tower" }
],
"height_cap": 290,
"info": { "title": "...", "zone": "...", "id": "BBL ...", "area": "... SF" },
"stats": { "Commercial FAR": "10.0", "Max Floor Area": "218,620 SF", ... }
}
Adapt the volumes array to the district type:
setbacksTo generate an interactive 3D viewer from this data, run: /zoning-envelope path/to/this-report.md
## Notes
- The NYC Zoning Resolution is maintained by the Department of City Planning
- PLUTO data is updated quarterly — verify currency for critical decisions
- Contextual districts (with letter suffixes) have mandatory streetwall and height rules that override standard bulk controls
- City of Yes for Housing Opportunity was adopted December 2024 — some provisions phase in over time
- When in doubt about district classification or applicable rules, always ask the user
- For split-zone lots, analyze each zone separately and note the complexity
- ZoLa (zola.planning.nyc.gov) is the authoritative visual reference — recommend users verify there