October 2024

The October 2024 release note for the OS MasterMap Topography Layer – Building Height Attribute product

Building Height Attribute (BHA) is an enhancement to, and forms part of, OS MasterMap Topography Layer. It provides a set of height attributes with a buildings theme within OS MasterMap Topography Layer.

Building Height Attribute tiles

• Total tiles: 9 985

• New tiles: 0

• Deleted tiles: 2 (NM7545 and NN4075)

Extent

The October 2024 BHA release contains building heights for 47 585 802 unique buildings, tanks, chimneys, and glasshouses across the entirety of Great Britain.

The total number of features is 47 769 527, including duplicate TOIDs. These are recorded when features overlap at tile edges.

Limitations

Some building TOIDs (Topographic Identifiers) in OS MasterMap Topography Layer will have no corresponding height values in the BHA data in areas of coverage. This can occur because of different update cycles or in instances when a building was constructed after the capture of the source BHA data. This is also the case when a building has failed quality validation checks and there is no existing data to replace it.

Building height values are generated from a fully automated process and, as such, the accuracy of the values is subject to tolerances governed by the process. Ordnance Survey specifically disclaims any warranty that OS MasterMap Topography Layer – BHA is of satisfactory quality or fitness for a particular purpose. We further disclaim any warranty that OS MasterMap Topography Layer – BHA is error free or accurate.

Next release

The next release of OS MasterMap Topography Layer – BHA is scheduled for April 2025.

The April 2025 release will include an updated ‘BHA_ProcessDate’ for each OS_TOPO_TOID as improvements are being made as part of our continuous work to improve the data.