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HM Land Registry's Use Land and Property Data

Technical guidance for GML files

GML format

GML is an open data format that is widely used across Europe and complies with the  EU INSPIRE Directive. HM Land Registry supports the use of open standards. We use the GML format to supply a standard data structure to users of all GIS/CAD systems.

How to use GML data in other tools or systems

The GML data format can be converted to other geographic information system (GIS) formats.

Depending on your system, you may need to convert GML to suit the data format of your GIS. Contact your GIS  provider for details of how to convert the format within your system.

To use GML data in different tools you may have to convert the data into a format used by that tool and also ensure the data is in an appropriate projection.

For example, if you want to use GML data in Google Maps you’ll have to convert the GML file into keyhole markup language (KML) format.

Quantum geographic information system (QGIS) is a free open source system that can be used to view GML data and convert it to other data formats.

How to open GML files

  1. Click the layer menu and add a vector layer.
  2. Browse to the location of your GML file and select the GML file type.
  3. Add the layer to your project.

How to convert GML data to different formats

  1. Add the GML layer to your project.
  2. Select the layer in the layer browser and right click on the layer.
  3. Click on save as and choose from the available formats such as:
    • ESRI shapefile
    • Mapinfo MIF or TAB
    • AutoCad DXF
    • GeoJson
    • KML

How to use polygons in mapping tools

HM Land Registry data is captured against the British National Grid. This means that each point that makes up a polygon is described by X and Y values. These values reference a point on the British National Grid.

You can use HM Land Registry’s INSPIRE Index Polygons in mapping tools such as Google or Bing Maps. The data will have to be re-projected from British National Grid into projections used by the Google or Bing tools. QGIS can re-project data from British National Grid (EPSG:27700) to a wide variety of other projections. These include the spheroid projections used by Google and Bing.

How to convert one projection to another

  1. After adding a vector data layer to QGIS, right click on the layer in the layer browser.
  2. Click save as and name your new layer.
  3. Project the layer into a new coordinate reference system (CRS), such as WGS 84 Pseudo Mercator (EPSG:3857) used by Google and Bing maps.
Warning Calculations used to convert data from one projection to another may introduce errors. It’s possible that the calculations used to convert data from British National Grid to WGS84 may shift the position of some features in the data by up to 15 metres.

Get detailed guidance about QGIS on the QGIS project website.