OS NGD Improvements
A high-level summary of data improvements implemented for the OS NGD.
2026 improvements
March 2026 – Improvements to the Field Boundary Feature Type
The Field Boundary Feature Type was added to the OS NGD in March 2024.
In March 2025, we introduced improvements to the automated method used to identify field boundary data; this update incorporated machine learning techniques to increase the accuracy and consistency of field boundary classification.
As part of our process, the output of all automatically classified field boundary features undergo a quality review. In March 2025, our thematic accuracy assessment showed that 7.7% of field boundary national coverage was classified as requiring improvement. Following the implementation of machine learning, this figure has reduced to 2.1% as of March 2026, raising classification performance and overall data quality.
Supplementary information covering how field boundary data is created, highlights of the attribution available, and the known limitations is available from the Field Boundary pages of the Using OS NGD Data section of this site. A full list of the attribution provided for Field Boundary features can be found on the Field Boundary Feature Type page in the Data Structure section.
February 2026 – Improvements to the OS Land Features, OS Land Use Features, OS Structure Features and OS Water Features Collections
Improvements were made to the OS NGD during a planned maintenance period in February 2026 to improve the accuracy, consistency, and validation of topographic data, as well as preparing for future product releases.
These improvements included:
A new method has been implemented for populating existing metadata Geometry Capture Method, Description Capture Method, OS Land Cover Capture Method and OS Land Use Capture Method attribution on Building Part, Land, Structure, Rail, Road Track Or Path, Water and Site Feature Types, which impacts the v2.0 and v3.0 schemas where this metadata is present. This may result in some one-off changes for some features in the OS NGD.
The description values of 'Ford' and 'Tidal Ford' were previously applied the wrong way around on Water Point features. This fix ensures that they are assigned correctly.
September 2025 to March 2026 – Improvements to data coverage for Bus Lane and Cycle Lane Feature Types
There was partial data coverage across Great Britain for the Bus Lane and Cycle Lane Feature Types between September 2025 (when the two feature types were released into the OS NGD) and March 2026, with iterative increases in coverage released monthly.
Full data coverage for Great Britain for the two feature types was achieved by March 2026.
The data went through thorough testing ahead of initial release in September 2025, followed by additional quality testing ahead of achieving full Great Britain-wide coverage in March 2026.
2025 improvements
September 2025 to December 2025 – Improvements to data coverage for Bus Lane and Cycle Lane Feature Types
There was partial data coverage across Great Britain for the Bus Lane and Cycle Lane Feature Types between September 2025 (when the two feature types were released into the OS NGD) and March 2026, with iterative increases in coverage released monthly.
Full data coverage for Great Britain for the two feature types was achieved by March 2026.
The data went through thorough testing ahead of initial release in September 2025, followed by additional quality testing ahead of achieving full Great Britain-wide coverage in March 2026.
July 2025 – Improvements to the OS Building Features, OS Land Features, OS Land Use Features, OS Structures Features and OS Water Features Collections
The following improvements will be implemented into the OS NGD during a planned maintenance period in July 2025.
Improvements on 'Industry And Business' and 'Business Or Industrial Park' Land Use Sites and related attribution on Topographic Areas
As a result, customers will see improvements to over 400 000 ‘Industry and Business’ and ‘Business or Industrial Park’ sites in the OS Land Use Features Collection and their corresponding topographic area feature (Building, Building Part, Land, Structure, and Water Feature Types). These enhancements will be visible in the OS Land Use Tier A attribute.
We have also improved the following OS Land Use Tier A definitions to improve clarity and the accuracy of classifications:
Commercial Activity: Industrial Or Manufacturing – Locations where raw materials are extracted or processed, or where component parts are made into finished items. This classification typically only applied to larger sites > 1ha in extent.
Commercial Activity: Other – Locations where commercial activities occur, where a more detailed classification has not been determined or are not otherwise categorised.
This was caused by our original background mappings which classified a commercial site as Industrial or Manufacturing by default when no further detail was available. This misleadingly resulted in retail areas or offices displaying as places where raw materials are extracted and processed where we do not currently have a data source. This will be a target area for future improvements.
Improvements to show the full lifecycle of a building in a single theme – OS NGD Buildings Theme
In preparation for the OS NGD product release in September 2025, we will be making some background changes to the OS NGD Buildings Theme. Approximately 39 000 features representing under-construction buildings – currently classified under the OS Land Features Collection – will be reclassified into the OS Building Features Collection. This transition will begin in June 2025, with the data initially appearing in the Building Part Feature Type. In the September 2025 OS NGD product release, the same data will also be available in the corresponding Building Feature Type.
These changes will enable a more complete view of the building lifecycle – from construction through to dereliction – within a single collection, ultimately delivering more valuable insights to our customers.
Improved depiction of inland water polygons no longer splitting inland water polygons with Topographic Lines
To improve customers’ ability to query and report using OS data, we will no longer be splitting inland water polygons where Topographic Lines for Ferry Alignments cross water polygons. As a result, Ferry Alignments will show as Minor Topographic Lines in both OS MasterMap Topography Layer and OS NGD themes, where Water polygon features formerly split by a ferry will merge into more logical single features.
Improved coverage of OS Land Use Tier B attribution on Solar Panels
Over 27 000 ‘Solar Panels on Bare Earth Or Grass’ within the OS NGD Structures Theme will have an OS Land Use Tier B of ‘Energy Generation’ added where they currently are null to improve accuracy of reporting for renewables.
Improvements to ‘Status’ of Roofed Castle Wall in OS NGD Building Part Feature Type
Currently 27 Roofed Castle Wall features are incorrectly listed with a Status of ‘Derelict’ in our Building Part Feature Type data. These are being updated to have a Status of ‘Unknown’ as there is no available information to confirm whether the features are in such disrepair that they can no longer serve their original purpose.
Improved consistency of intertidal classifications on features in the OS NGD Land and OS NGD Water Themes
As part of our background work to improve the data quality of features within the intertidal zone, 23 features currently attributed as ‘Inter Tidal + Reeds’ located in the OS NGD Water Theme will be reclassified and published in the OS NGD Land Theme as ‘Saltmarsh’ features with Is Tidal attribute = true in the product reflecting their correct environmental context.
Improved consistency of Weirs in the OS NGD Structures Theme
To enhance the customer experience, we have revised mappings to consolidate almost all ‘weir’ and ‘roofed weir’ features into the OS NGD Structures Theme. Weirs that do not make up the tidal extent will now be published as Structures in all cases. Those that are necessary for tidal boundaries will remain in the OS NGD Water Theme. As a result, approximately 8 000 new features will be added to the Structure Line Feature Type, which sits within the OS Structure Features Collection of the OS NGD Structures Theme. The Change Type attribute will therefore show as ‘Moved From A Different Feature Type.’
Knowing the location of weirs is useful for flood planning, monitoring freshwater ecosystems and environmental modelling.
Please note, there are 53 roofed weirs which have not moved to the OS NGD Structures Theme as part of this data improvement, and these will remain in the OS NGD Buildings Theme.
Improved consistency of Slipways in the OS NGD Land Theme
Previously, slipways were categorised into two separate themes within the OS NGD product. Slipways below the tidal extent were classified as Structures, while those above the tide line were classified as Land. To enhance the customer experience, we have revised the mappings to consolidate all slipway features previously in the OS NGD Structures Theme into the OS NGD Land Theme, with the Is Tidal attribute set to 'true'. In addition, to better the customer experience, this change also allows for easier implementation of lifecycle for the OS ESG (Slipways) product. As a result, approximately 3 800 weir features will be added to the Land Feature Type, and will be removed from the Structure Feature Type.
Improvements to ‘Grandstands’ in the Building and Building Part Feature Types
As part of ongoing improvements to the OS NGD, approximately 60 features currently in the OS Structure Features Collection with a classification of 'Grandstand' will move to the OS Building Features Collection, where they will have other descriptions such as ‘Stand’ to improve consistency and accuracy of capture of Building Access Locations.
June 2025 – OS NGD GSS code data improvements for OS Building Features, OS Land Features, OS Transport Features, OS Structure Features and OS Water Features Collections
We are pleased to share a recent enhancement which improves how administrative boundary changes are reflected in the OS NGD ‘Features’ Collections.
We have enhanced the assignment and maintenance of Government Statistical Service (GSS) codes, which are used to accurately identify a wide range of UK geographical areas for statistical and administrative purposes. This improvement increases the precision and reliability of boundary representation within our datasets.
The feature types affected are:
Building Part v2.0
Land v3.0
Road Track Or Path v3.0
Structures v3.0
Water v3.0
This improvement will be incorporated in the June 2025 OS NGD 'Features' Collections daily updates from 13/06/2025. As a result of this improvement work, customers receiving daily updates may receive larger than usual Change-Only Updates (COUs) and customers taking monthly supplies may receive larger than usual COUs in their July 2025 data package.
We anticipate similar levels of change in October 2025 and May 2026, aligned with updates to the OS Boundaries Collection, as we continue to deliver the most up-to-date data possible.
June 2025 – Building Feature Type data improvements for Basement Presence, Construction Material and Building Age
As a result of work in collaboration with Verisk, there will be improvements made in June 2025 to the Basement Presence, Construction Material and Building Age attribution in the Building Feature Type. This work has involved improving the processing of energy performance certificate (EPC) data to increase accuracy; changes in some capture type and confidence levels in OS NGD data may be seen.
As a result of this improvement work, customers may receive larger than usual Change-Only Updates (COUs) if they take a daily supply of Building Feature Type data schema versions 2.0, 3.0 and 4.0 throughout June 2025 as the data flows through. Customers taking their supply monthly of this feature type may receive larger than usual COUs in their July 2025 data package. No action is required by customers.
If you have any questions, please get in touch.
May 2025 – Height data enhancement for OS NGD Structures Theme and OS NGD Buildings Theme data
At Ordnance Survey, we are modernising our data creation platforms. This includes the creation of additional height data for our building and structures datasets. A recent key improvement we've made as part of these efforts was to improve the accuracy and granularity of the height evidence date attribute, which details the date of capture for the imagery used to derive the height data.
Previously, height metadata was derived from large imagery flight blocks (exceeding 500km²), which sometimes required several flights over multiple days. This occasionally resulted in buildings and structures being assigned an imagery date different from the actual capture date.
Our new system allows the population of imagery date metadata to a more granular level, using the appropriate flight block. This ensures there is only one imagery date per building or structure feature, giving a more accurate representation of height evidence date for a specific feature. As a result, from 10 May 2025, some customers using Change-Only Updates (COUs) may notice that a small number of height evidence dates have changed to slightly older dates as we move to the new system. This change reflects more accurate data, not incorrect data.
This impacts some features in the following data schema versions:
Structure Feature Type v1.0, v2.0 and v3.0
Building Part Feature Type v1.0 and v2.0
Building Feature Type v4.0
Some customers may also see a larger than usual supply of COU if taking a daily supply of the above data schema versions as change begins to flow into the data from the start of our flying season, where data is captured using aerial imagery during the National Cyclic Revision (NCR) programme.
The .xlsx file below contains a complete list of features across all feature types that have a revised height evidence date that's earlier than previously stated.
Please see Data schema versioning for more information about versioning in the OS NGD.
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