OS MasterMap Topography Layer upgrade

Improved descriptive terms attribution allows you to identify, interrogate and visualise more features than ever before!

OS MasterMap Topography Layer's Descriptive terms will update over 11 million features across land, rivers, water and structures. See a full list of newly identifiable features in our Excel guide or request the sample data


When will the new descriptive terms be available?

There will be a staged roll-out of descriptive terms into the main MasterMap Topography Layer product.

What can descriptive terms be used for?

Land use analysis

Identify agricultural land, foreshore, saltmarsh and others to more accurately describe your land cover and terrain

Risk modelling

Assess value and risk by evaluating land use, water, structures and specific features in your area of interest

Flooding Resilience

Detailed water features and foreshore, substations, structures, for risk analysis and fast access in an emergency

What descriptive terms are available?

We’re adding 76 new descriptive terms, such as bridge, level crossing and wind turbine. With 11 million more real-world features identified, you can tag and analyse your assets more precisely.


Through the creation of the descriptive group of 'structure', individual built features can now be identified and categorised. From emergency telephones and bridges to wind turbines and telecommunications masts, a wide range of features are becoming available.

Agricultural land

A brand new descriptive term, this will be applied to areas of land with the main purpose of growing crops or keeping livestock. Along with additional foreshore and land-fill descriptive term attributes, this makes land use much clearer.

Clearer tide lines

The updated descriptive terms give a clearer depiction of tidal range. Where high and low tide are coincident (e.g in docks used by larger ships, which are always full), the descriptive terms for Mean High Water (Springs) will appear with Mean Low Water (Springs) or other features such as Groyne or Building Outline.

How can they be styled?

We’re introducing new styling options for both current and upgraded Topography Layer including style sheets in SLD, LYR and QML formats.

These are available on GitHub, supported by version control, user guides and release notes.

Styling resources:

OSMM Topography Layer stylesheets on Github

Cartographic styling update for new descriptive terms (PDF)

Full Topography Layer user guide (PDF)

Descriptive terms sample data

We’ve been working with our partners and software vendors to ensure they’re ready for these changes. If you create your own software or systems to translate Topography Layer, this change could affect you, so please test this sample data.

This sample data covers two areas - Exeter and Hampshire/Isle of Wight.

For existing OS Partners please contact the partner team to request your sample data

For all other audiences, please use this sample data file (4.8 GB file)

If you need any additional help with sample data, please contact our Customer Services team.

More Questions? Get in touch

If you have more questions about descriptive terms, please use the forum, or contact us directly:

OS MasterMap Topo forum

Contact us via email