How a Homeowner or General Contractor Can Use the Kolmo MCP in Claude to Answer Seattle Permitting Questions

GeekWire ran an impressive story this week: Seattle software engineer turned general contractor built an AI guide to the patchwork of permit rules (Kurt Schlosser, October 2, 2026).

If you’ve ever tried to figure out whether your project needs a permit in the Seattle area, you already know the problem. The answer depends on which city you’re in, which zone your lot sits in, how tall the thing is, and which of a dozen PDFs you happened to find first.

Pascal Matta’s Kolmo Construction company has a free permit checking tool

Pascal Matta spent his career building software at places like Google and T-Mobile. Then he wanted a deck on his Seattle house, and discovered that municipal code is a lot harder to read than software code. The rules for setbacks, height limits, and whether a permit was even needed were scattered across city web pages and PDFs, and they didn’t agree with each other from one city to the next.

He never built that deck. Instead, he started Kolmo Construction, his own general contracting company, and built a free tool to untangle the rules: kolmo.io/permits.

A few things stood out to me:

• It’s big. According to the article, it covers 457 verified rules across 80 jurisdictions in King, Pierce, and Snohomish counties, and every rule links back to the city’s own source page and exact wording.
• It’s grounded. The AI behind it (Google’s Gemini) answers from that verified rule text, not from general knowledge, which is how you keep a permit tool from making things up.
• It’s visual. Enter an address and you get a 3D view of your lot’s buildable envelope: setbacks, height limits, existing structures.
• It’s maintained. An automated weekly job re-checks the source pages, and the results go to a public data-quality log.
• It’s free. Matta says Seattle alone runs about $2,000 a month in AI costs, and he has no plans to paywall it or sell your data.

And then the part that made me want to write this post: he exposed the whole database over MCP, the Model Context Protocol. That means you don’t have to use his website at all. You can plug the permit data straight into your own AI assistant.

What’s an MCP, and why should you care?

An MCP server is a plug-in for AI assistants. Once it’s connected, your assistant can call it like a reference desk: instead of guessing at Seattle’s deck rules from whatever it absorbed during training, Claude asks Kolmo’s database and answers from the actual rule, with a link to the source.

Kolmo’s server is public, needs no account or API key, and is read-only, with one exception I’ll cover below. Here’s how to connect it.

How to install the Kolmo MCP in Claude

Option 1: The Claude app (claude.ai or Claude Desktop)

This is the one most homeowners will want.

1. Open Claude and go to Settings → Connectors.
2. Click Add custom connector.
3. Name it Kolmo, and paste this URL:

https://www.kolmo.io/mcp

4. Click Add. There’s no login or OAuth step.
5. Start a new chat and make sure the Kolmo connector is switched on in the chat’s tools menu.

A few notes:

• Custom connectors work on every plan, including Free, but the Free plan is limited to one custom connector.
• On a Team or Enterprise plan, an organization owner has to add the connector first (in Admin settings → Connectors). Then you connect to it from your own Settings.
• Claude will warn you that this connector isn’t verified by Anthropic. That’s true of every custom connector. Kolmo’s tools are read-only except one, submit_contact_request, which sends a quote request to Kolmo Construction. Claude should only use it if you ask, and by default it asks your permission before running a connector’s tools.

Option 2: Claude Code

If you live in the terminal (and plenty of GCs with a tech streak do), it’s one line:

claude mcp add --scope user --transport http kolmo https://www.kolmo.io/mcp

--scope user makes it available in every project. Start a new session, and the tools load automatically.

What it looks like in use

I ran three real questions through it to see what comes back. For the parcel-specific questions, I used a typical single-family lot in Wallingford.

Homeowner: “Do I need a permit for my deck?”

I want to add a ~200 sq ft deck about 30 inches off the ground behind my house at [my address], Seattle. Do I need a permit, and what will it cost?

Claude looked up the parcel, checked the deck rules, estimated the fee, and pulled the submittal checklist. The answer:

• Yes, you need a permit. In Seattle, decks 18 inches or less above grade (and outside environmentally critical areas) are exempt. At 30 inches, this one isn’t.
• It qualifies for a simpler permit. It’s a Subject-to-Field-Inspection (STFI) permit, and an architect or engineer stamp typically isn’t required.
• The fee came out to $813.53 at a $15,000 project valuation: the building fee, a 40% STFI plan review charge, and the tech and state surcharges, all computed from the 2026 SDCI fee schedule, with the formula shown. Final fees are set by the city when it accepts your application.
• Inspections: footing, framing, and final.
• What to submit: a site plan with setbacks, the Statement of Financial Responsibility form, and a setback and lot-coverage check. It even gave this lot’s setbacks: 7 ft average front and rear, 5 ft side.
• Sources: SDCI’s deck page and Tips 103 and 316, with links.

That’s the background check you’d otherwise spend an evening assembling from the SDCI website.

Homeowner: “Do I need a permit for a heat pump, and does it matter which city I’m in?”

Do I need a permit to replace my gas furnace with a heat pump in Seattle? What about Bellevue?

• Both cities require one. It’s a mechanical permit, plus an electrical permit if you need a new circuit, plus plumbing if the condensate goes to a drain.
• The process differs. Seattle goes through SDCI. Bellevue applies through MyBuildingPermit.com.
• Both want equipment specs and Manual J/S/D sizing for a new system, and a gas leak test where a gas line is involved.
• It flagged the WA heat pump rebates (HEEHRA, through energy.wa.gov). That’s a nice touch.

General contractor: “Is this sub legit, and what’s happening on this block?”

I’m a GC. Check that license KOLMOL*753JS is active, bonded, and insured, confirm it can pull a Seattle deck permit, and show me recent permit activity near [address].

• License check, from WA L&I data updated daily: active, general contractor specialty, $30,000 bond active, $1M insurance active, with expiration dates and a link to verify on the L&I site.
• Permit match: the license’s specialty covers everything a Seattle deck permit requires.
• Neighborhood activity: 79 permits within about 1,500 feet in the last two years, broken down by type, with sample projects and their valuations. That’s useful for sizing up a neighborhood before you bid, and it’s pulled from Seattle’s open permit data.

For a GC, the license and specialty check alone is worth installing it for. It’s the step everyone means to do before hiring a sub, and now it’s one sentence.

A few honest caveats

It’s a genuinely useful tool, and it’s also a new one. In my testing:

• Ask one question at a time, or ask Claude to use the structured tools. When I bundled “do I need a permit, what will it cost, and how long will it take” into one question, the general Q&A tool only answered the last part. Asking separately (or letting Claude chain the permit, fee, and submittal tools, as it did above) got complete answers.
• There are no review timelines yet. “How long will it take” came back empty for every project I tried. Call the permit center for that.
• Check the address it found. If you mistype a house number, it snaps to the nearest parcel and warns you. Make sure it’s your lot before you rely on the setbacks.
• Zone-specific numbers deserve a second look. On my test lot, one general note quoted setbacks for a different zone than the parcel lookup did. The parcel-specific number is the one to trust, and the city is the final word.
• Neighborhood permit activity is Seattle-only for now.

None of that is a reason not to use it. It’s a reason to treat it the way you’d treat a sharp, well-read friend: a great first answer with sources attached, and the city’s word as final.

What does this mean for General Contractors?

Your customers will show up informed. A homeowner who asked Claude about their deck already knows they need a permit, roughly what it costs, and what their setbacks are. Explaining the permit process used to set you apart. Now it’s the starting point, and you win the job on schedule, price, and how you run a site.

They can vet you in one sentence. The same tool that checks a sub’s license checks yours. Active license, bond, insurance, and expiration dates, straight from L&I. If something has lapsed, the homeowner sees it before you get a call.

The contractor who is the source is one step from the lead. Kolmo didn’t just publish permit rules. Its MCP server also gives estimates and can send a quote request to Kolmo Construction when the user asks. A homeowner researching a permit in Claude is one question away from “can you build it?”, and Kolmo is already in that conversation.

You don’t need to build a permit database to compete with that. But you do need your own information to be easy for an AI to find and trust:

• Your license number, bond, and insurance on your site
• A clear service area
• Project pages with real neighborhoods and costs
• A complete Google Business Profile

Most local businesses aren’t going to build a permit database. But every one of them can make their information clear, structured, and easy for an AI to trust. If you want help getting your business into Google, Google Maps, and AI answers, that’s what I do.