> For the complete documentation index, see [llms.txt](https://docs.os.uk/os-downloads/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.os.uk/os-downloads/products/areas-and-zones-portfolio/os-open-built-up-areas/os-open-built-up-areas-technical-specification.md).

# OS Open Built Up Areas Technical Specification

OS Open Built Up Areas is a dataset representing the built-up areas of Great Britain. It was designed primarily to underpin the statistical analysis that contributes to policy enablement across the public sector.

The Office for National Statistics (ONS) and Scottish Government made significant contributions in the design of the dataset to ensure it is fit for purpose and focussed on the needs of the wider public sector.

OS Open Built Up Areas is released and maintained as an OS OpenData product with Open Government Licensing (OGL), enabling you to use it for a wide range of purposes.

<figure><img src="/files/h5b3VJwXMlSw4mEvB8hZ" alt="Example map showing OS Open Built Up Areas data. Built up areas in and around London are shown in yellow."><figcaption><p>Representative map showing OS Open Built Up Areas around London</p></figcaption></figure>

This technical specification includes the following sections:

* [Methodology](/os-downloads/products/areas-and-zones-portfolio/os-open-built-up-areas/os-open-built-up-areas-technical-specification/methodology.md)
* [Identifiers](/os-downloads/products/areas-and-zones-portfolio/os-open-built-up-areas/os-open-built-up-areas-technical-specification/identifiers.md)
* [Feature types](/os-downloads/products/areas-and-zones-portfolio/os-open-built-up-areas/os-open-built-up-areas-technical-specification/feature-types.md)
* [Structured data types](/os-downloads/products/areas-and-zones-portfolio/os-open-built-up-areas/os-open-built-up-areas-technical-specification/structured-data-types.md)
* [Code list](/os-downloads/products/areas-and-zones-portfolio/os-open-built-up-areas/os-open-built-up-areas-technical-specification/code-list.md)
* [Supply formats](/os-downloads/products/areas-and-zones-portfolio/os-open-built-up-areas/os-open-built-up-areas-technical-specification/supply-formats.md)


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