OS MasterMap® Topography Layer – Building Height Attribute:
alpha 2 release note (July 2014)
Introduction
The OS MasterMap® Topography Layer – Building Height Attribute is an enhancement to, and forms
part of, the OS MasterMap Topography Layer. It was first released in an early (alpha) form in March
2014. This second alpha release adds more content, increasing the area covered to 10,000km 2 of the
main towns and cities in Great Britain. The purpose of this alpha release is to enable customers and
partners to start to use the data and to provide feedback to Ordnance Survey that will help us further
develop this attribution.
These 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 – Building Height Attribute is of
satisfactory quality or fitness for a particular purpose. We further disclaim any warranty that OS
MasterMap® Topography Layer – Building Height Attribute is error free or accurate.
Product Metadata
As a guide only, the following product metadata is estimated,
 Coverage area = approx. 10,000km2
 Number of building polygons with attributes = 23.65 million
Extent
The spatial extent of this alpha release is shown in Figure 1, and can also be viewed using the
interactive map interactive map available on our website.
Known issues
The Tile_Ref attribute for TOIDs in tile ST76 is given as a 10km grid reference rather than a 5km
reference as stated in the Technical Specification.
Due to an issue with the data provided in Alpha release 1, the data in tile ST17NE has been updated. All
other data provided in release 1 is unchanged.
OS MasterMap® Topography Layer – Building Height Attribute:
alpha release notes v1.2
24/07/2014 © Crown copyright
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Figure 1: OS MasterMap® Topography Layer – Building Height Attribute alpha release coverage (July 2014)
OS MasterMap® Topography Layer – Building Height Attribute:
alpha release notes v1.2
24/07/2014 © Crown copyright
Page 2