---
title: "Organic / Irregular"
url: "https://commonwaysystem.org/patterns/network/organic-irregular/"
id: "NET-ORG-04"
description: "An unplanned, irregular network shaped incrementally over time by terrain, property lines, and historical settlement patterns rather than a deliberate overall layout, typically found in historic or pre-industrial city cores."
updated: "2026-09-26"
---

# Organic / Irregular

`NET-ORG-04`

Descriptive Network

Organic / Irregular

An unplanned, irregular network shaped incrementally over time by terrain, property lines, and historical settlement patterns rather than a deliberate overall layout, typically found in historic or pre-industrial city cores.

## Related Media

The items below come from outside the Commonway System, external videos, podcasts, and articles related to this page's topic, not part of the guidebook itself.

Aligned

### [Can U.S. Cities Build Narrow European Streets?](https://www.youtube.com/watch?v=iv9fWEekFUM)

City Beautiful

The video contrasts rigid, car-scaled American grids with the organic narrow streets of older European cities, using Philadelphia's Elfreth's Alley and Quince Street as rare U.S. examples, and names fire-truck access, parking minimums and zoning as the barriers to building more. It is a direct look at the Commonway System's Grid and Organic/Irregular network patterns and the narrow, shared local street patterns, from Alley to Living Street and Pedestrian Plaza.

## Why this pattern exists

Organic/Irregular networks are a real, common existing condition, especially in historic cores worldwide, and the Patterns section’s role is descriptive documentation of what exists, not prescriptive endorsement of what to build. This pattern is documented for that reason: Commonway System does not recommend building new organic/irregular networks, but existing ones are a genuine, common reality that needs naming and description like any other topology.[1]

## Key considerations

-   Irregular orientation and angularity often produce natural traffic calming through unpredictability and reduced sightlines, an incidental but real benefit of this topology
-   Retrofitting modern accessibility and modal infrastructure into an organic network requires context-sensitive, block-by-block approaches rather than standard geometric assumptions that work on a regular grid
-   Closely corresponds to Marshall’s A-type/Altstadt, typically found at a settlement’s historic core

## Related patterns

[Grid](https://commonwaysystem.org/patterns/network/grid.md) (NET-GRD-01), [Radial](https://commonwaysystem.org/patterns/network/radial.md) (NET-RAD-03), [Dendritic/Hierarchical](https://commonwaysystem.org/patterns/network/dendritic-hierarchical.md) (NET-DEN-02) (contrasting Network topologies); Marshall’s A-type/Altstadt

## References

1.  Precedent-based Marshall, Stephen. _Streets and Patterns_. London: Spon Press, 2005. Chapter 4, "Pattern Type," "Developing Typologies of Pattern" (ABCD typology, A-type/Altstadt), pp. 83-96. Print/ebook source, no persistent URL to monitor.