commentletter.com

The engine

Built on Ichi, the building-code engine.

Ichi is an AI platform for building-code compliance, made by Ichi Plan, Inc. in California. It licenses the code books, loads each city's amendments, reads construction documents at full length, and cites the exact section and the exact spot in a file for every claim. Our AI agent is that engine, pointed at one document: the letter your city sends back.

ichiplan.com · Ichi (一) means “one” in Japanese.

Why a comment letter needs this engine

A comment letter is a set of claims about the code and about your drawings. “Provide egress width calculations per CBC 1005.3” says the code requires something and that the plans do not show it. Answering it means reading the section in the edition your city adopted, and reading your own sheets to see whether the thing is there. A general chatbot can do neither: it answers from memory and truncates a plan set at its context window.

Ichi was built for exactly that reading. It is why a report here can mark a comment as a real deficiency, as already satisfied on a named sheet, or as a citation that does not govern this project, and show its evidence for each. Every improvement to how Ichi reads a code book or a plan set reaches this product the same day.

What the engine brings to your report

  1. 01

    It holds the code, licensed

    Ichi is an authorized ICC licensee. The state codes and the model codes underneath them are loaded as books, with the amendments each city adopts on top, so a citation points at the sentence that governs your project, in the edition your city adopted.

  2. 02

    It reads the whole plan set

    Construction documents run to hundreds of sheets and thousands of pages. Ichi indexes every sheet, detail and schedule you upload and reads them in full, which is how a response can say which sheet already shows the fix.

  3. 03

    It cites, every time

    Every claim carries a link to the exact code section and the exact spot in your files. Nothing is asserted from memory. If the engine cannot find the evidence, the report says so instead of sounding confident.

  4. 04

    It is used by the people who write the letters

    Jurisdictions, third-party plan review firms, design teams and contractors run Ichi for code compliance work every day. The reviewer's side of the table and yours are reading from the same engine.

In their words

More customer stories on ichiplan.com
Being able to ask a question and have it recite a bunch of sections you weren't even aware existed — that's huge.
Eric SchneiderjohnEric SchneiderjohnVP, Supervising Plan Review Engineer · West Coast Code Consultants
One of the things Ichi is going to do is bring design professionals, applicants like us, and jurisdiction plan reviewers closer together.
Mike WellsMike WellsPrincipal · Stratus Real Estate Developers
I can type in a question and immediately see all the relevant code sections related to it. That saves time — rather than waiting two weeks.
Gage SchliceGage SchliceFire Marshal · City fire prevention division

The company

Ichi Plan, Inc. builds Ichi and commentletter.com. The company is backed by Costanoa Ventures and Tapestry VC. Its thesis is simple: construction's AI has to be grounded in the codes that govern every project, and in the judgment that brings those codes to life, or it is just another general model.

Read more about the platform, the company, or the jurisdictions that run on it. If you review plans for a living, Ichi itself is the tool; if you are answering one letter, you are in the right place.

Answer your letter on this engine.

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