Euclid HL

AI Planning & Zoning Platform — Real Questions, Cited Answers, Live GIS Mapping

AI
LLM
RAG
GIS
ArcGIS Maps SDK

24/7

immediate, accurate, always available

100%

answers from adopted plans and ordinances

30%+

increase in staff productivity

Project Overview

Euclid HL turns a community's adopted plans and ordinances — documents that span hundreds of pages of text, maps, and technical diagrams — into a living layer residents and staff can simply ask. Every answer is grounded in the adopted code, cited to the governing section, and linked to the parcel on the map; when a diagram answers better than text, the relevant figure comes back with the response.

Built at Houseal Lavigne by combining GIS technology with large language models, it's a platform, not a chatbot: staff interpretations accrue on the code itself as institutional memory, and it's now live in communities across North America.

The Live Product

Rebuilt here in code, not a screenshot: the Cornwall, Ontario deployment — a cited answer on the left, the live zoning map with the parcel highlighted on the right.

euclidhl.ca/on/cornwall
LIVE

Cornwall

ONTARIO · CANADA

e

Hi, I'm Euclid HL for Cornwall, your planning and zoning assistant.

How high can I build in the General Commercial zone?
e
In the General Commercial (GC) zone, the maximum building height is 13.5 m — roughly four storeys. Setbacks step up where a lot abuts a Residential Zone.
§11.2 GC Zone standardsZone: General Commercial
What would you like help with?

Euclid HL can make mistakes. Check important info.

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Cornwall Zoning

Agricultural
Commercial
Employment
Floodplain
Residential

Municipal Boundary

Every Question Answered from the Source

Zoning, comprehensive plans, by-laws, process and procedure — answered from each community's adopted documents and cited to the section.

Cañon City, ColoradoZoning

“I have property at 923 Main Street. Can I open a restaurant here?”

Yes — if your parcel is in the GC, General Commercial district, a sit-down restaurant is permitted by right. You'll still need a building permit for tenant improvements and a county retail food license.

§19.10.080 Allowable usesGC General CommercialCañon City UDC, Title 19
Cornwall, OntarioBy-law

“How tall can my fence be on a corner lot?”

On a corner lot, the Zoning By-law adds the rule that matters most: a 6 m sight triangle must be kept clear at the intersection so sightlines stay open. Where a yard abuts a Residential Zone, a 1.86 m screening fence is required.

Street AStreet BCorner lotsight triangle6 m6 m

Figure returned with the answer · 6 m sight triangle

Zoning By-law 2022-001§15.3.7 ScreeningSight triangle · 6 m
Burbank, CaliforniaADU

“Can I build an ADU behind my house?”

Yes — a detached ADU is capped at 850 sq ft (one bedroom) with a 4-ft rear and side setback. ADUs are exempt from the usual FAR, lot-coverage and open-space limits, and no extra parking is required when the lot is near transit.

Burbank Zoning · Ch.1 Div.3 (ADUs)Gov. Code §66314

Conversations are illustrative of production behavior; answers in deployment are grounded in each community's adopted code.

Live Across North America

From its first deployment in Cañon City, Colorado, Euclid HL has grown to communities across the United States and Canada.

CornwallOntario, CanadaCañon CityColoradoBurbankCaliforniaChattanoogaTennesseeSanta AnaCaliforniaTemple CityCaliforniaMadera CountyCaliforniaFerguson TownshipPennsylvaniaSouth Whitehall TownshipPennsylvania

A Platform, Not a Chatbot

The conversational layer is the front door. Behind it, Euclid HL builds the institutional memory of how a city plans and governs itself.

Grounded answers, real citations

Every response traces to the adopted code section that governs it. Residents see the source, not a summary of one.

Parcel-linked, map-native

Ask about an address, see the parcel. Zoning, planning designation, overlays, and boundaries rendered live alongside the conversation.

Returns the diagram, not just the text

Setback figures, build-to illustrations, encroachment graphics, and renderings — included when a picture answers the question better.

Integrates policy and regulations

Planning policy and zoning regulations are related, but very different. Euclid HL knows the difference and accurately answers questions about both.

Institutional memory, built in

Staff interpretations and annotations accrue in the platform. When a senior planner retires, the knowledge stays.

Place intelligence, city to neighborhood

Track what issues are neighborhood-specific or common city-wide, so staff know what matters most where — and can act on it.

Technical Implementation

AI Architecture

  • Agent-based LLM framework for autonomous decision-making
  • Retrieval-augmented generation grounding every answer in the adopted code, with section-level citations
  • Defensive guardrails that route questions needing staff judgment to staff
  • Conversation logging and administrative review capabilities

GIS Integration

  • ArcGIS Maps SDK rendering parcels, zoning, and overlays live alongside the conversation
  • Regulations bound to the parcels they govern — ask about an address, see it highlighted on the map
  • Figures, diagrams, and special-area plans returned with answers when a picture explains it better

Experience Euclid HL

Explore the product site, or try the live Cornwall, Ontario deployment and ask it a real planning question.

Project Team & Roles

James Patton
Lead Software Architect – Houseal Lavigne AssociatesHelped develop the overall system architecture and implemented both the frontend and backend components.
Devin Lavigne
Principal | Cofounder – Houseal Lavigne AssociatesDeveloped the vector database, engineered prompt workflows, and structured the project's data architecture.
Sujan Shrestha
Planner II – Houseal Lavigne AssociatesDesigned custom maps and visual graphics to enhance the project's spatial analysis and user experience.