The Zoning Gap

Where does Indianapolis zoning disagree with its own comprehensive plan — and in which direction? That’s the question the Zoning Gap project answers, parcel by parcel, across all of Marion County. The interactive map is in development; the method is public now, because the method is the point.

The idea

Indianapolis has two rulebooks. The zoning code says what you may build today. The Marion County Land Use Plan — the Pattern Book and its maps — says what the city intends for each place. Everyone assumes they roughly agree. Nobody has measured where they don’t.

When they disagree, it runs in one of two directions:

The method

Rather than hand-judging 630 combinations of zoning district and plan typology, the matrix is derived from two small calibration tables. Every zoning district gets an intensity rank (1–10, from D-A at 1 to the CBD core at 10). Every Pattern Book typology gets an intended intensity range (Suburban Neighborhood intends 2–4; Urban Mixed-Use intends 7–9). A district below its typology’s range is underzoned; above it, overzoned; a use-family mismatch (industrial zoning under a neighborhood typology) is flagged on its own terms.

Every classification traces to a stated rule. Disagree with a cell and you’re really disagreeing with one of about forty calibration numbers — which is a productive argument to have in public, and one this page will host openly.

The first draft calibration finds 72 underzoned district/typology pairs countywide — the “plan says yes, code says no” inventory.

Why it matters

Petitioners and neighbors argue about rezonings one at a time, as if each were a referendum. The Gap map reframes the question: many petitions aren’t asking for a favor — they’re asking for consistency. And where the city is systematically underzoned against its own plan, that’s not an anecdote; it’s a policy backlog you can measure in acres.

The method is fully exportable. Every city with a comprehensive plan has a zoning gap. Indianapolis is simply going to be the first to see its own.

Data: City of Indianapolis MapIndy GIS (zoning districts, Land Use Plan typologies). Method and calibration tables will be published alongside the map. Questions and calibration arguments welcome — that’s what the digest is for.