Known Data Issues
This page lists known data issues in relation to the OS National Geographic Database (NGD) themes, collections and feature types. The OS NGD is in its infancy and, as such, will be largely developed and iterated upon in its early life.
As and when we resolve a known data issue, we will remove it from this page.
Generic OS NGD known data issues
Very small number of features not being given the correct 'End of Life' change type
There are 319 features (out of 600+ million) which reside within the 'features' collections (i.e. any OS NGD collection which has a name of 'XXX Features', for example, Transport Features) that have not been given the correct 'End of Life' change type. This means that these features still reside within the supply but should be deleted.
Topographic features missing from four feature types
From 26 September 2024 to 31 October 2024, an issue affected the following four OS NGD feature types, causing features to be missing from the data:
OS NGD Building Part Feature Type: ~80 000 features are missing from data schema v2.0 compared to data schema v1.0.
OS NGD Land Feature Type: ~38 000 features are missing from data schema v3.0 compared to data schema v2.0.
OS NGD Water and OS NGD Structure Feature Types: ~100 features are missing in total across both feature types from data schema v3.0 compared to data schema v2.0.
For example, where an affected Building feature should be visible, a blank area will instead be seen, creating a ‘gap’:
UPDATE: This issue was resolved on 31 October 2024. Any data ordered or provided after this date will include the fixed data.
Please note, we advise against using counts from the four aforementioned affected OS NGD feature type datasets when taking historic snapshots of data between 26 September 2024 and 31 October 2024 as the counts may not be accurate due to the missing topographic features.
3D geometry missing in GeoPackage format for some feature types in the OS NGD Transport Network and Water Network Collections
In the OS NGD Transport Network Collection and OS NGD Water Network Collection, there are multiple feature types that contain 3D geometry. We are aware of an issue where 3D geometry is not being supplied in the GeoPackage format. This issue impacts the following feature types: Connecting Link, Connecting Node, Ferry Link, Ferry Node, Path Link, Path Node, Road Link, Road Node, Water Link and Water Node. Customers taking CSV format will not be affected. UPDATE: This issue was resolved on 26 November 2024. To receive updated data:
Customers who have only ordered once: Customers will need to re-order to receive the corrected data.
Monthly Update Customers: 01 December monthly updates with corrected data will be supplied as normal. Annual Update Customers: 01 January annual updates with corrected data will be supplied as normal.
OS NGD Address Theme known data issues
Interruption to the supply of daily updates for OS NGD Address
There is currently an ongoing issue affecting the supply of daily updates for both OS NGD Address and the OS Places API.
As a result, daily Change-Only Updates (COUs) for Thursday 14 and Friday 15 November 2024 have not been made available to customers. The latest currency for OS NGD Address is Tuesday 12 November 2024. We are working to resolve this issue.
UPDATE (on 15/11/2024):
The two aforementioned missing daily COUs for OS NGD Address should be available on Saturday 16 November 2024 in the daily OS NGD Address Theme COU.
OS Places API now has the latest currency of data available to customers; it was updated at 22.13 on Thursday 14 November and all missing updates were included.
UPDATE (on 18/11/2024)
All delayed OS NGD Address updates were released to customers on 16/11/2024.
Daily COUs have resumed as normal.
Isle of Man addresses
A total of 32 address records are currently present in the OS NGD GB Address Collection which should not be contained within this collection as they are actually Isle of Man records. These records are correctly present in the OS NGD Islands Address Collection.
Incorrect change type for addresses moving between feature types
In a very small number of cases, when an address moves between feature types, such as moving from Pre-Build Address to Built Address, the change type given is incorrect.
The address 'leaving' the Pre-Build Address Feature Type is correctly marked 'Moved To', but when it enters the Built Address Feature Type, it is incorrectly marked as 'New' rather than 'Moved From'.
Your Change-Only Update (COU) processing will still work correctly, and your data holdings will be complete, but the address will have been incorrectly marked as 'New'.
OS NGD Administrative and Statistical Units Theme known data issues
Historic European Region Feature Type
This feature type contains updates made to the boundaries post 01 April 2021 (when the feature type was frozen in the Boundary-Line product). This means that there will be differences between the boundaries accessed via our OS OpenData pages and those accessed via OS NGD.
Three Missing Parishes from the 'Parish or Community' Layer
The Margaret March, Tollard Royal and Marlow Bottom Civil Parish (CP) within the Parish or Community layer is missing from the current (October 2024) release of data. This issue is currently being investigated and we are working to fix it for a future release.
OS NGD Buildings Theme known data issues
Incorrect building height values for some multi-storey properties with a single storey annexe
Some residential two-storey properties with a large adjoining single storey are returning as a single storey when created using machine learning (due to incorrect building height values), for example, two-storey houses with attached garages or large rear extensions.
Additional in-scope buildings included in the Number of Floors data
Some notable non-residential and non-office buildings that meet the scope will be included (for example, several cathedrals and arenas).
Some in-scope residential buildings are excluded from the Number of Floors data
Some in-scope residential buildings have no Number of Floors value (for example, new builds, and buildings failing height validation rules).
Some apartment block buildings are excluded from the Number of Floors data
Apartment blocks that have their address geometry situated in the stairwell of the building and have their building geometry segregated due to the Land Use Site Feature Type will not get a Number of Floors value.
OS NGD Land Theme known data issues
Site count discrepancies for some Land features
In a small number of instances, the Containing Site Count attribute presents the wrong value in Land features. This error only impacts 0.7% of Land features, and we expect it to be fixed by early October 2024. UPDATE: This issue was resolved on 12 October 2024. Any data ordered or provided after this date will include the fixed data.
OS NGD Structures Theme known data issues
Some underground Structure features are missing from the Habitat Coverage cross reference table
Three underground Structure features with an OS Land Cover Tier B attribute of ‘Coniferous Trees’, ‘Non-Coniferous Trees’, ‘Scattered Coniferous Trees’ or ‘Scattered Non-Coniferous Trees’ are missing from the corresponding Habitat Coverage Reference cross reference table.
Overlapping Field Boundary
features exist
Approx. 20 000 Field Boundary features are overlapping. This issue is currently being investigated.
Field Boundary data quality
At the time of launch of the Field Boundary Feature Type (March 2024), areas of Great Britain were still to be quality checked and will be improved as part of OS’s continuous quality review programme when updated imagery is available. Most of the known data quality errors are either in Moorland areas or where imagery was captured earlier in the year and vegetated features are ‘leaf-off’. The downloadable file below contains the status of each 10km2 area relating to the quality of the Field Boundary feature classification.
Temporal differences to data currency for bridge interactions
Bridges in the OS NGD Structure Features Collection are updated daily, whereas networks in the OS NGD Transport Network Collection and the OS NGD Water Network Collection are updated monthly and quarterly, respectively.
Completeness for bridge interactions
On rare occasions where Network Over and Network Under attribution cannot be identified (i.e. disused bridges or viaducts over dry valleys), the attributes will not be populated (i.e. will be ‘null’).
Overlapping of stacked bridges
Where bridges cross one other, it can be difficult to identify the correct networks running over and / or under each bridge.
OS NGD Transport Theme known data issues
Incorrect speed values
Speed data is supplied quarterly from our third-party supplier. We have identified an issue in which OS have not correctly processed this data. This has resulted in possible incorrect values in the Average and Indicative Speed Feature Type.
UPDATE: This issue was resolved on 25 July 2024. Any data ordered or provided after this date will include the fixed data.
Welsh speed limit changes
On 17 September 2023, default 20 mph speed limits were introduced across Wales. We are aware that these changes are not yet reflected in the Average and Indicative Speed Feature Type. Speed limit data is supplied by our third-party supplier quarterly. The most recent supply occurred before the Welsh speed limit changes took place and therefore will not be reflected in the OS NGD until the next supply. We expect the updated Welsh speed limits to be in NGD from December 2023. UPDATE: This issue was resolved on 13 December 2023. Any data ordered or provided after this date will include updated Welsh speed limit data.
Incorrect speed values
In the Average and Indicative Speed Feature Type, the indicative speed value for individual Road Links can be inferred by Ordnance Survey. We are aware that in certain instances some of these indicative speed values are incorrect. We are working to resolve this issue and have an approximate implementation date of the start of July 2023. This issue impacts just over 2% (174 000) of the total Road Links in the Average and Indicative Speed Feature Type. UPDATE: This issue was resolved on 02 July 2023. Any data ordered or provided after this date will include the fixed data.
OS NGD Water Theme known data issues
Invalid geometries in Waterbody Catchment and River Basin District Catchment features
Some catchment polygons appear to have invalid geometries in the form of self-intersections, holes, and gaps. Instances of self-intersection are primarily due to the gridded digital terrain model (DTM) used to generate the catchment data provided by the third-party data from authoritative bodies.
Incorrect representation of a Waterbody Catchment name
The Barlings Eau Upper catchment name is incorrectly displayed. This is as per the third-party data from the authoritative bodies.
Non-unique Waterbody Catchment IDs
Two instances occur where the Waterbody Catchment ID is not unique: GB109056040082 and GB104027063230. This is as per the third-party data from the authoritative bodies.
Certain Waterbody Catchment features do not nest exactly within a River Basin District Catchment.
A total of 14 instances occur where Waterbody Catchments do not nest exactly within their associated River Basin District Catchment. This is as per the third-party data from the authoritative bodies.
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