How to get building heights from 3d TopographicArea Building layer?

[eabase]

How can I access the 3d attribute for building height, RelHMax:

    map.on('style.load', function() {
        // Duplicate 'OS/TopographicArea_2/Building/1' layer to extrude the buildings
        // in 3D using the Building Height Attribute (RelHMax) value.

I only want to get the building height for a particular grid location or TOID/UPRN, so I don't need to plot anything else on a map. How can this be done using any of the OS products?

[tmnnrs]

Hi @eabase. You can also obtain the building height attribution from the OS Features API. Here are a couple of code examples which demonstrate how you could achieve this:

• https://labs.os.uk/public/os-data-hub-examples/os-features-api/wfs-example-get-feature
• https://labs.os.uk/public/os-data-hub-examples/os-features-api/wfs-example-topo-toid-search

Alternatively you could use something like vector-tile-query. This repo is no longer maintained; but should allow you to query the attribution directly from the vector tiles.

[eabase]

Hi @tmnnrs
Thank you for the reply. However, I cannot find any reference to building height in any of those examples. Perhaps you can briefly explain how this could be done, using those examples?

[tmnnrs]

Hello @eabase

These examples have been configured to return only a limited set of the available attributes for the TopographicAreas (in this case TOID + DescriptiveGroup + SHAPE) through use of the propertyName query parameter.

Excluding this parameter will result in the full set of attributes (including those for the building heights) being returned.

You can return a description of the attributes for each feature type supported by the WFS service by performing a DescribeFeatureType request: https://api.os.uk/features/v1/wfs?service=wfs&version=2.0.0&request=DescribeFeatureType&key=.