Explain Code

Interpret a single code section — paste the text or cite the §, get plain-English meaning plus jurisdictional amendment flags. Output is an inline interpretation with §-level citation. For a multi-section compliance audit use the code-review skill; to retrieve the code text first route through arch-rag.

Input you need

Before interpreting, gather:

Code + edition — exact code and adopted edition:
- IBC — IBC 2024, IBC 2021, IBC 2018. Adopted edition varies by jurisdiction (NYC DOB still on IBC 2014 with NYC amendments as of 2026; California on 2022 CBC derived from IBC 2021; Toronto Building on OBC 2024 derived from NBC 2020).
- IECC — IECC 2024, IECC 2021, IECC 2018. Climate-zone aware.
- NFPA — NFPA 101 2024 (Life Safety), NFPA 1 2024 (Fire Code), NFPA 13 2025 (Sprinklers), NFPA 72 2025 (Fire Alarm).
- ADA — 2010 ADA Standards for Accessible Design. Companion: ANSI A117.1-2017. Some states overlay (CA Title 24 Part 2 Ch. 11B is stricter on several clauses).
- IRC — IRC 2024 for 1- and 2-family dwellings and townhouses.
- NBC (Canada) — NBC 2020 plus provincial code (OBC 2024, BCBC 2024, Quebec Construction Code Ch. I).
Section reference — §X.Y.Z form: IBC 2024 §1006.3.4 (egress from stories), IECC 2024 §C402.1.4 (R-value alternative), NFPA 101 2024 §7.2.1.6 (door egress), 2010 ADA §404.2.4 (door maneuvering clearance).
Code text — provide one of:
- A paste of the section text (preferred — exact wording matters).
- The § + edition, with arch-rag already indexed for that PDF; this command then routes to arch-rag to retrieve, then interprets.
- Do not paraphrase or reconstruct code text from memory across editions.
Jurisdiction — name a specific NA AHJ when amendments matter: NYC DOB, FDNY, LADBS, DSA, CA HCAI, Toronto Building, Boston ISD, Chicago DOB, Houston Public Works, Miami-Dade RER, GSA, USACE. Many jurisdictions amend the I-code base (NYC has its own NYC BC overlay; California publishes CBC / CMC / CEC / CRC; Florida publishes FBC).
Project context — occupancy group (B, R-2, A-3, E, I-2, S-1), construction type (I-A … V-B), height and area, sprinklered status, and existing-vs-new. The same § often reads differently across these dimensions.
Specific question — what the user wants to know. Examples: "Does this require a 1-hour rated corridor?", "Is travel distance 200 ft or 250 ft for B occupancy?", "What triggers an area of refuge?"

If any required input is missing, list the gap and stop. Do not interpret a § without seeing the actual code text.

Output structure

Produce a single Markdown response in this layout:

# Explain Code — [Code §, plain title]

**Code:** [IBC 2024 / IECC 2024 / NFPA 101 2024 / 2010 ADA / NBC 2020]
**Section:** [§1006.3.4 — Egress from stories or occupied roofs]
**Jurisdiction:** [NYC DOB / LADBS / DSA / CA HCAI / Toronto Building / etc.]
**Occupancy / Type:** [B occupancy / Type II-B / sprinklered / 4 stories / 50 ft]
**Question:** [the user's specific question]

---

## What the section says (literal)

> [Verbatim quote of the operative language. If the section has numbered exceptions, list them as a sub-bullet.]

(IBC 2024 §1006.3.4)

## Plain-English meaning

[3–5 sentences. What the section requires, when it applies, what triggers the requirement. Use concrete examples sized to the project context. Translate code-speak ("means of egress", "in accordance with") into builder language without losing precision.]

## How it applies here

- [Bullet — apply to the project context. e.g., "For a B-occupancy 3-story sprinklered building, this means two exits from L3 are required because the occupant load on that floor exceeds 30."]
- [Bullet — adjacent sections that interact. e.g., "Cross-check IBC 2024 §1017 (travel distance) and §1020 (corridors) — the same exit count drives all three."]
- [Bullet — climate / sprinkler / occupancy condition that flips the answer.]

## Jurisdictional amendments to verify

- **[Specific AHJ]** — [Known local amendment. e.g., "NYC BC §1006 modifies the IBC base table — verify against the latest NYC DOB code revision before relying on the I-code answer."]
- **State / provincial layer** — [If applicable. e.g., "California amends to 2022 CBC §1006 with stricter limits in I-occupancy — verify with DSA for K-12 or CA HCAI for hospitals."]
- **Federal overlay** — [`GSA P-100`, `USACE UFC 3-600-01`, `VA Design Manual`, `FEMA P-2055` if the project is federally regulated.]
- If no jurisdiction-specific amendment is known, state that explicitly. Do not guess.

## Cross-references

- [Bullet — related § to pull next. e.g., "IBC 2024 §1004 (occupant load) — the trigger for §1006."]
- [Bullet — referenced standards. e.g., "NFPA 13 §8.15 referenced for sprinkler protection of the assembly."]
- [Bullet — companion code. e.g., "2010 ADA §404.2 governs door clearance; verify against IBC 2024 §1010 for egress door hardware."]

## Caveats

- This is an interpretation aid, not a code determination. The Architect of Record's stamped opinion governs, not this command. For binding interpretation, file the jurisdiction-specific clarification process — NYC DOB Code Determination, LADBS Information Bulletin, DSA Interpretation of Regulations, or equivalent — or engage a code consultant.
- Code editions and amendments change. Verify which edition the jurisdiction has adopted; many adopt 1–2 cycles behind ICC publication.
- For sweeps across multiple § use the `code-review` skill — this command does single-§ interpretation only.
- If the code text was not pasted, route through `arch-rag` first to retrieve verbatim. Do not interpret from memory.

NA AEC conventions (enforce)

English only. No Hangul anywhere.
Imperial-first units (ft, in, sf, °F, psf, Btu, R-values). Metric in parens only when useful. Do not lead with mm, m², °C, W/m²K. Use R-values, never metric U-values.
Codes cited — IBC / IRC / IECC / NFPA / 2010 ADA / ANSI A117.1 / ASCE 7 / ASHRAE / NBC (Canada) and provincial codes. Never KBC, KS, EN, BS, JIS, DIN — out of catalog scope.
Section format — always code + edition + §X.Y.Z: IBC 2024 §1006.3.4, IECC 2024 §C402.1.4, NFPA 101 2024 §7.2.1.6, 2010 ADA §404.2.4. Never "section 1006" generically.
AHJs — name specifically: NYC DOB, FDNY, LADBS, DSA, CA HCAI, Toronto Building, Chicago DOB, Houston Public Works, Miami-Dade RER, GSA, USACE. Never the AHJ, the city, or local authority generically.
Floor labels — Level 3, L3, or 3rd floor. Never 3F.
Roles — Architect of Record (AOR), Engineer of Record (EOR), Owner, Owner's Representative, Code Consultant, Expediter (NYC). Never use Director as a project role.
Climate zones for IECC questions — pair with climate-zone-mapper, or cite the zone explicitly (e.g., CZ 4A for NYC, CZ 3B for LA, CZ 6A for Toronto, CZ 2A for Houston).

Constraints

Do not invent code text. If the user did not paste the §, either ask for the paste or route through arch-rag to retrieve verbatim from an indexed PDF. Memorized code text is unreliable across editions.
Do not invent jurisdictional amendments. If the NYC / California / Toronto overlay on a § is not known, state that — do not fabricate amendment numbers.
Distinguish literal code text (verbatim, blockquoted) from interpretation (plain English) — keep them in separate sections.
Distinguish base I-code requirement from AHJ amendment — a NYC DOB or DSA answer can flip versus the IBC base.
Coexists with code-review (multi-§ audit) and arch-rag (PDF retrieval). Redirect there for scope larger than a single §.
Markdown only. No Word / PDF output, no aec-doc-gen dependency.
Always include the Caveats section. Code interpretation without an AOR stamp is non-binding by definition.

Workflow

Echo back what was parsed: code + edition, §, jurisdiction, occupancy + type, question. One line.
If the code text is missing, list the gap and stop. Suggest arch-rag to retrieve the verbatim section from an indexed PDF.
If the jurisdiction is missing on a question where amendments matter (egress, sprinkler triggers, energy compliance, occupancy classification), ask before interpreting.
Produce the full Markdown response in one shot.
After the response, list cross-referenced § the user should pull next (e.g., "For occupant load, pull IBC 2024 §1004 — re-run /explain-code or use arch-rag").

Explain Code

Input you need

Before interpreting, gather:

Code + edition — exact code and adopted edition:

IBC — IBC 2024, IBC 2021, IBC 2018. Adopted edition varies by jurisdiction (NYC DOB still on IBC 2014 with NYC amendments as of 2026; California on 2022 CBC derived from IBC 2021; Toronto Building on OBC 2024 derived from NBC 2020).
IECC — IECC 2024, IECC 2021, IECC 2018. Climate-zone aware.
NFPA — NFPA 101 2024 (Life Safety), NFPA 1 2024 (Fire Code), NFPA 13 2025 (Sprinklers), NFPA 72 2025 (Fire Alarm).
ADA — 2010 ADA Standards for Accessible Design. Companion: ANSI A117.1-2017. Some states overlay (CA Title 24 Part 2 Ch. 11B is stricter on several clauses).
IRC — IRC 2024 for 1- and 2-family dwellings and townhouses.
NBC (Canada) — NBC 2020 plus provincial code (OBC 2024, BCBC 2024, Quebec Construction Code Ch. I).

Section reference — §X.Y.Z form: IBC 2024 §1006.3.4 (egress from stories), IECC 2024 §C402.1.4 (R-value alternative), NFPA 101 2024 §7.2.1.6 (door egress), 2010 ADA §404.2.4 (door maneuvering clearance).

Code text — provide one of:

A paste of the section text (preferred — exact wording matters).
The § + edition, with arch-rag already indexed for that PDF; this command then routes to arch-rag to retrieve, then interprets.
Do not paraphrase or reconstruct code text from memory across editions.

Jurisdiction — name a specific NA AHJ when amendments matter: NYC DOB, FDNY, LADBS, DSA, CA HCAI, Toronto Building, Boston ISD, Chicago DOB, Houston Public Works, Miami-Dade RER, GSA, USACE. Many jurisdictions amend the I-code base (NYC has its own NYC BC overlay; California publishes CBC / CMC / CEC / CRC; Florida publishes FBC).

Project context — occupancy group (B, R-2, A-3, E, I-2, S-1), construction type (I-A … V-B), height and area, sprinklered status, and existing-vs-new. The same § often reads differently across these dimensions.

Specific question — what the user wants to know. Examples: "Does this require a 1-hour rated corridor?", "Is travel distance 200 ft or 250 ft for B occupancy?", "What triggers an area of refuge?"

If any required input is missing, list the gap and stop. Do not interpret a § without seeing the actual code text.

Output structure

Produce a single Markdown response in this layout:

# Explain Code — [Code §, plain title] **Code:** [IBC 2024 / IECC 2024 / NFPA 101 2024 / 2010 ADA / NBC 2020] **Section:** [§1006.3.4 — Egress from stories or occupied roofs] **Jurisdiction:** [NYC DOB / LADBS / DSA / CA HCAI / Toronto Building / etc.] **Occupancy / Type:** [B occupancy / Type II-B / sprinklered / 4 stories / 50 ft] **Question:** [the user's specific question] --- ## What the section says (literal) > [Verbatim quote of the operative language. If the section has numbered exceptions, list them as a sub-bullet.] (IBC 2024 §1006.3.4) ## Plain-English meaning [3–5 sentences. What the section requires, when it applies, what triggers the requirement. Use concrete examples sized to the project context. Translate code-speak ("means of egress", "in accordance with") into builder language without losing precision.] ## How it applies here - [Bullet — apply to the project context. e.g., "For a B-occupancy 3-story sprinklered building, this means two exits from L3 are required because the occupant load on that floor exceeds 30."] - [Bullet — adjacent sections that interact. e.g., "Cross-check IBC 2024 §1017 (travel distance) and §1020 (corridors) — the same exit count drives all three."] - [Bullet — climate / sprinkler / occupancy condition that flips the answer.] ## Jurisdictional amendments to verify - **[Specific AHJ]** — [Known local amendment. e.g., "NYC BC §1006 modifies the IBC base table — verify against the latest NYC DOB code revision before relying on the I-code answer."] - **State / provincial layer** — [If applicable. e.g., "California amends to 2022 CBC §1006 with stricter limits in I-occupancy — verify with DSA for K-12 or CA HCAI for hospitals."] - **Federal overlay** — [`GSA P-100`, `USACE UFC 3-600-01`, `VA Design Manual`, `FEMA P-2055` if the project is federally regulated.] - If no jurisdiction-specific amendment is known, state that explicitly. Do not guess. ## Cross-references - [Bullet — related § to pull next. e.g., "IBC 2024 §1004 (occupant load) — the trigger for §1006."] - [Bullet — referenced standards. e.g., "NFPA 13 §8.15 referenced for sprinkler protection of the assembly."] - [Bullet — companion code. e.g., "2010 ADA §404.2 governs door clearance; verify against IBC 2024 §1010 for egress door hardware."] ## Caveats - This is an interpretation aid, not a code determination. The Architect of Record's stamped opinion governs, not this command. For binding interpretation, file the jurisdiction-specific clarification process — NYC DOB Code Determination, LADBS Information Bulletin, DSA Interpretation of Regulations, or equivalent — or engage a code consultant. - Code editions and amendments change. Verify which edition the jurisdiction has adopted; many adopt 1–2 cycles behind ICC publication. - For sweeps across multiple § use the `code-review` skill — this command does single-§ interpretation only. - If the code text was not pasted, route through `arch-rag` first to retrieve verbatim. Do not interpret from memory.

NA AEC conventions (enforce)

English only. No Hangul anywhere.

Imperial-first units (ft, in, sf, °F, psf, Btu, R-values). Metric in parens only when useful. Do not lead with mm, m², °C, W/m²K. Use R-values, never metric U-values.

Codes cited — IBC / IRC / IECC / NFPA / 2010 ADA / ANSI A117.1 / ASCE 7 / ASHRAE / NBC (Canada) and provincial codes. Never KBC, KS, EN, BS, JIS, DIN — out of catalog scope.

Section format — always code + edition + §X.Y.Z: IBC 2024 §1006.3.4, IECC 2024 §C402.1.4, NFPA 101 2024 §7.2.1.6, 2010 ADA §404.2.4. Never "section 1006" generically.

AHJs — name specifically: NYC DOB, FDNY, LADBS, DSA, CA HCAI, Toronto Building, Chicago DOB, Houston Public Works, Miami-Dade RER, GSA, USACE. Never the AHJ, the city, or local authority generically.

Floor labels — Level 3, L3, or 3rd floor. Never 3F.

Roles — Architect of Record (AOR), Engineer of Record (EOR), Owner, Owner's Representative, Code Consultant, Expediter (NYC). Never use Director as a project role.

Climate zones for IECC questions — pair with climate-zone-mapper, or cite the zone explicitly (e.g., CZ 4A for NYC, CZ 3B for LA, CZ 6A for Toronto, CZ 2A for Houston).

Constraints

Do not invent code text. If the user did not paste the §, either ask for the paste or route through arch-rag to retrieve verbatim from an indexed PDF. Memorized code text is unreliable across editions.

Do not invent jurisdictional amendments. If the NYC / California / Toronto overlay on a § is not known, state that — do not fabricate amendment numbers.

Distinguish literal code text (verbatim, blockquoted) from interpretation (plain English) — keep them in separate sections.

Distinguish base I-code requirement from AHJ amendment — a NYC DOB or DSA answer can flip versus the IBC base.

Coexists with code-review (multi-§ audit) and arch-rag (PDF retrieval). Redirect there for scope larger than a single §.

Markdown only. No Word / PDF output, no aec-doc-gen dependency.

Always include the Caveats section. Code interpretation without an AOR stamp is non-binding by definition.

Workflow

Echo back what was parsed: code + edition, §, jurisdiction, occupancy + type, question. One line.

If the code text is missing, list the gap and stop. Suggest arch-rag to retrieve the verbatim section from an indexed PDF.

If the jurisdiction is missing on a question where amendments matter (egress, sprinkler triggers, energy compliance, occupancy classification), ask before interpreting.

Produce the full Markdown response in one shot.

After the response, list cross-referenced § the user should pull next (e.g., "For occupant load, pull IBC 2024 §1004 — re-run /explain-code or use arch-rag").

Explain Code.

Explain Code

Input you need

Output structure

NA AEC conventions (enforce)

Constraints

Workflow

Explain Code.

Explain Code

Input you need

Output structure

NA AEC conventions (enforce)

Constraints

Workflow