Building Part and Building Line Feature Types
A Lightning Talk
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A Lightning Talk
Last updated
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There are four feature types in the OS NGD Buildings theme. The first two have the same geometry as their equivalent features in OS MasterMap Topography Layer but all with new OS NGD attribution and are covered on this page. The third, added in September 2023, is comprised of merged Building Part features. The fourth, added in March 2025, is newly captured data about access points to certain key public buildings and are covered in the section.
Polygon features representing either a complete separate building or a larger building where internal divisions have been dissolved to leave single feature. such as with a hospital or school.
The OS NGD Buildings data comes in two formats, CSV and GeoPackage (GPKG)
The GeoPackage format comes ready to load into the GIS package of the users choice with different gpkg files for each layer.
The CSV format is more suited for loading into a database. It has all of the same layers in csv format and all the same attribution as the GeoPackage, however instead of storing the geometry in a GIS-ready format, it is stored as a LINESTRING (Building Line), or POLYGON (Building Part/ Building) attribute with all of the vertices stored as co-ordinate pairs in the text file.
The OS NGD Buildings attribution varies between the Feature Types. However:
All OS NGD data has an OSID, version, version date and changetype
Where the data has an ancestry from OS MasterMap there is a TOID
The data now has source, evidence and update dates so users can see where the information has come from and when it was updated
There is also extra data around if the feature is obscured and the specification it was captured to
Where data was present in the Building Heights Attribution that data has been included against Building Part polygons
Absolute Height Roof Base. The height, above datum, of the base of the roof, that is, where the roof intersects the building walls
Relative Height Roof Base. The difference in height between the intersection of the external building walls and the underlying ground surface and the base of the roof of the building
Absolute Height Maximum. The height, above datum, of the highest point of the building, this could include a chimney or other structure on a building
Relative Height Maximum. The difference in height between the intersection of the external building walls and the underlying ground surface and the highest point on the building
Absolute Height Minimum. The height, above datum, of the underlying ground surface
Height Confidence Level. The confidence in the quality of the height attributes for the building or structure expressed in qualitative terms
There is a series of newly released attribution, and attributes to support the new data
OS Land Cover Tier A: A high-level description of the land cover; more detail is provided in the OS Land Cover Tier B attribute​
OS Land Cover Tier B: A detailed description of the land cover type. Up to five distinct land cover types can be applied​
OS Land Use Tier A: A high-level description of the main activity that takes place at the location or that the feature supports​
OS Land Use Tier B : A detailed description of the main activity that takes place at the location or that the feature supports​
Ordnance Survey surveyors and remote sensing teams have been capturing and maintaining information on land cover, land use and a more detailed level of description for over 10 years.​
This data has then been transformed to match attribution for existing products, such as OS MasterMap Topography Layer​
However, in the OS NGD data it is being published at the original, more granular level
Links that may be useful:
This content has been developed from what was originally a Lightning Talk PowerPoint slide set. These slides are available to PSGA members to view and download from the
