NYC Zoning Lookup

Overview

Answer questions about the New York City Zoning Resolution by downloading the official combined PDF (~100 MB, ~1700 pages) once, building a section-to-page outline, and reading the targeted pages on demand. Every answer quotes the relevant clause and cites it with section number and page (e.g., §23-145, p.142). The skill operates with zero external dependencies — only Claude Code's built-in Bash and Read tools.

When to use

Trigger on:

• NYC-specific zoning terms: FAR, lot coverage, setback, side/rear/front yard, sky exposure plane, height factor, dwelling unit factor (DUF), use group, accessory use, community facility, daylight evaluation.
• District codes: R1–R10 residence, C1–C8 commercial, M1–M3 manufacturing, contextual variants (R6A, R6B, etc.), commercial overlays (C2-4 over R6, etc.).
• Special District names: Special Hudson Yards District, Special West Chelsea District, Special Midtown District, Special Garment Center District, etc.
• Direct citation requests: what does §23-145 say, look up ZR Article II Chapter 3, Special Permit §74-71.
• ZR text amendments referenced by NYC DOB, DCP, or BSA filings.

Do NOT trigger for:

• Non-NYC zoning (any other US city or Canadian municipality) — use zoning-summary.
• NYC Building Code (Title 28) questions — different document, different lookup.
• DCP zoning maps / GIS lookups (current zoning of a specific lot, rezoning history) — the ZR PDF has text and tables, not maps.
• NYC Multiple Dwelling Law, Housing Maintenance Code, NYCEEC — different documents.
• Procedural questions about how to file a variance, special permit, or text amendment with BSA / CPC — those belong elsewhere.

Workflow

Step 1 — Check the cache

Run:

test -f ~/.archtmpl/pdfs/nyc-zoning/zr-complete.pdf \
  && test -f ~/.archtmpl/pdfs/nyc-zoning/outline.md \
  && echo cached || echo missing

If cached, skip to Step 4. If missing, run Steps 2 and 3.

Step 2 — Download the NYC ZR Complete PDF (first time only)

mkdir -p ~/.archtmpl/pdfs/nyc-zoning
curl -fSL --progress-bar \
  "https://zoningresolution.planning.nyc.gov/sites/default/files/article/Zoning%20Resolution%20Complete.pdf" \
  -o ~/.archtmpl/pdfs/nyc-zoning/zr-complete.pdf

Verify:

file ~/.archtmpl/pdfs/nyc-zoning/zr-complete.pdf   # expect: "PDF document"
ls -lh ~/.archtmpl/pdfs/nyc-zoning/zr-complete.pdf  # expect: ~95–100 MB

If the file is below 50 MB or file reports anything other than PDF document, the URL likely returned an error or redirect. Stop and report — do not proceed with a corrupt cache.

Step 3 — Build the section-to-page outline (first time only)

The NYC ZR is organized as 14 Articles, each with multiple Chapters and numbered §X-XX sections (where the first digit is the Article number for Articles I–IX, and the first two digits for Articles X–XIV).

Locate the Table of Contents:

• Use the Read tool with pages: "1-15" to find the TOC or Article Listing.
• If not in the first 15 pages, scan in chunks (pages: "15-35", "35-60") until the TOC is located.

Read the full TOC across whatever page range it occupies. Extract every Article heading, every Chapter heading within each Article, and every numbered §X-XX section with its starting page.

Write ~/.archtmpl/pdfs/nyc-zoning/outline.md with sections like:

# NYC Zoning Resolution — Outline
Total pages: <N>
Last cached: <YYYY-MM-DD>

## Article I — General Provisions — pp. X–Y
### Chapter 1 — Title, Establishment of Districts and Incorporation of Maps — pp. X–Y
- §11-00 Title — p. X
- §11-10 Establishment of Districts — p. X

Skip detailed sub-paragraph numbering like (a)(2)(i) — those are reached by reading the section's pages, not by indexing.

If the document's TOC is incomplete or non-standard, fall back to extracting Article and Chapter headings only, by sampling every 30–50 pages and recording the first §X-XX section number on each sampled page. Note this fallback approach in the outline header.

Step 4 — Answer the user's question

For each question:

1. Re-read the outline. Always start by reading ~/.archtmpl/pdfs/nyc-zoning/outline.md to refresh the section map.
2. Identify the 1–3 most relevant §X-XX sections. State them explicitly before reading. Use references/zr_structure.md to map the question topic to the likely Article and Chapter. Examples:
   • Max FAR in R6 → §23-145 (R6 bulk regulations) and §23-15X (height-factor alternative).
   • Side yard for R5 detached → §23-462 (side yards in R3–R5).
   • Use Group 6 in C2 → §32-15 (use groups by district).
   • Special Hudson Yards bulk → §93-2X (Article IX).
3. Read those pages with the Read tool. Stay within the 20-page-per-call limit; chunk across calls if needed.
4. Quote the relevant clause verbatim and cite it. Use the format defined in references/citation_format.md:

   <exact quoted text from the ZR>

   — §23-145, p.142

5. If the answer is missing, expand once. Read the adjacent sections (one more Read call). If still not found, say Not found in the sections checked: [list]. Never invent section numbers, FAR ratios, height limits, setback distances, or use group assignments.

Rules

• Quote NYC ZR values verbatim. Never paraphrase a FAR ratio, height limit, sky exposure plane angle, required yard depth, or use group number.
• Cite every quoted value with section + page: §X-XX, p.N. Multiple sources separated by semicolons. Page numbers refer to the cached PDF's page index.
• Cross-references inside the ZR (e.g., as set forth in §23-32) are normative — chase the chain by reading the referenced section before answering.
• Definitions live in §12-10 (Article I, Chapter 2). When a quoted clause depends on a defined term whose meaning materially affects the answer, look up the definition there and quote it too.
• The Zoning Resolution is amended frequently. The cached PDF reflects the date in outline.md's Last cached header — when answering questions about a recent amendment, mention the cache date and offer to re-cache.
• Tables (use group lists, bulk tables, parking schedules) often span multiple pages. Read the full range when quoting tabular data, and quote cell values verbatim.
• Output language: English with NA conventions (FAR as a unitless ratio, heights in feet, distances in feet/inches).

Anti-patterns

• Answering NYC zoning questions from memory without reading the cached PDF. Always quote-and-cite.
• Reading the entire 1700-page PDF into context. Use the outline to target the 5–15 pages most likely to contain the answer.
• Citing only the section without the page number (§23-145 alone). Always append , p.N.
• Inventing section numbers when the targeted pages did not contain the §X-XX needed. Expand the read once, then report not found.
• Falling back to zoning-summary for NYC questions — that skill produces a generic NA worksheet, not citation-grade NYC ZR answers.
• Confusing the Zoning Resolution with the NYC Building Code (Title 28), Multiple Dwelling Law, NYC Administrative Code, or Housing Maintenance Code — different documents, different citations.
• Re-downloading the PDF on every query. Cache is reused; refresh only on explicit user request or when outline.md is older than 90 days.
• Recommending the user check the document elsewhere when the cached PDF already answers the question.

Resources

• references/citation_format.md — exact citation conventions for NYC ZR (§X-XX, p.N), Special District naming, definition lookups, cross-reference handling
• references/zr_structure.md — Article-by-Article overview and topic-to-Article quick lookup (where to find FAR, yards, use groups, special districts, parking, definitions)