OS MasterMap Sites Layer provides a nationally maintained view of the detailed extents of important locations such as airports, schools, hospitals, utility and infrastructure sites, and more. The points of access and routing points, to navigate in and out of the sites, are also provided.

OS MasterMap Sites Layer shows what people see in the real world, where the common view of something (such as a school) is not the address, the main building or the playing fields, but is the site as a whole.

How to get this product

Access to this product is free for PSGA members. Find out if you are a PSGA member or find other ways to access OS MasterMap Sites Layer data by visiting the product page with links to all of the relevant resources.

Visualise OS MasterMap Sites Layer data online

Available formats

OS MasterMap Sites Layer is supplied in three different formats:

• Geography Markup Language (GML) 3.2.1

• GeoPackage

• Vector tiles (MBTiles)

Product supply mechanism

OS MasterMap Sites Layer incorporates a web-based ordering system that allows customers to order their initial data supply and any updates, obtain price estimates and view details of their holdings on demand. The product is supplied as an online download. You can download data in various formats from the OS Data Hub.

Coverage and file sizes

For GML, OS MasterMap Sites Layer is a national dataset and is maintained and supplied as 5km² tiles of data via Area of Interest (AOI) supply or as Great Britain (GB) supply. File size estimates can vary from about 2 KB compressed to about 162 KB (compressed) for tile supply. A full GB supply will be approximately 43 MB compressed. Compression rates vary and are dependent on the size and content of a tile.

For GeoPackage and vector tiles, the coverage will be GB supply only. The file size is approximately 90 MB zipped for GeoPackage, and 160 MB zipped for vector tiles.

Change-only updates

Change-only updates (COU) are not available for OS MasterMap Sites Layer.

OS MasterMap Sites Layer provides a nationally consistent representation of polygon features that represent the area or extent of certain types of function or activity with the appropriate attribution. The product also includes access points to assist in navigating into and out of the sites (with references to OS MasterMap Highways Network – Roads product).

Feature type counts

Product quality

There are no significant issues that would impair the use of this product in the April 2024 release. However, there is one minor error identified with this release that users should be aware of:

1. There are 26 instances of Access Point features not intersecting the edge of the associated Functional Site, whereby the Access Point geometry is between 5 and 100m in distance from the referenced Functional Site.

* Routing Points are no longer supplied from October 2023 release onwards (see Product Improvements section)

Product improvements

To meet customer needs, Ordnance Survey has created a fully routable multi-modal network, and a key element of this is to provide more usable data about the access to destinations. To this end, we are now directly splitting our road, track and path data where Access Link features connect to the network; this will allow customers to more easily route into sites using OS network data.

Whereas previously some Access Points referenced Routing Points, all will now reference a Road Node from OS MasterMap Highways Network – Roads product. Consequently, there is no requirement for Routing Point features, and these features are no longer suppled as part of OS MasterMap Sites Layer.

As a result, no Routing Point layer has been supplied from the October 2023 publication onwards.

For customers that use GML format, there is no change to the schema so product loading should be unaffected. However please be aware that for customers using GeoPackage no table for Routing Points is provided and similarly for vector tile format no layer for Routing Points is provided.

Next release

The next release of OS MasterMap Sites Layer is scheduled for October 2024.

OS MasterMap Sites Layer provides a nationally consistent representation of polygon features that represent the area or extent of certain types of function or activity in Sites with the appropriate attribution. The product also includes Access Points to assist users in navigating into and out of the Sites (with references to the OS MasterMap Highways Network – Roads product).

Feature type counts

Product quality

There are no significant issues that would impair the use of this product in the October 2024 release. However, two minor errors have been identified with this release that users should be aware of:

1. There are 25 instances of Access Point features not intersecting the edge of the associated Functional Site, whereby the Access Point geometry is between 5m and 100m in distance from the referenced Functional Site.

2. 327 Access Points reference Road Nodes that do not exist in the latest OS MasterMap Highways Network – Roads product release, although this error is often due to the timing of the releases not lining up.

*Routing Points are no longer supplied from the October 2023 release onwards (see the Product Improvements section for full details).

Product improvements

To meet customer needs, Ordnance Survey has created a fully routable multi-modal network, and a key element of this is to provide more usable data about the access to destinations. To this end, we are now directly splitting our Road, Track and Path data where Access Link features connect to the network; this will allow customers to more easily route into Sites using OS network data.

Whereas previously some Access Points referenced Routing Points, all will now reference a Road Node from the OS MasterMap Highways Network – Roads product. Consequently, there is no requirement for Routing Point features, and these features are no longer suppled as part of the OS MasterMap Sites Layer product.

As a result, the Routing Point layer has not been supplied from the October 2023 publication onwards.

For customers that use Geography Markup Language (GML) format, there is no change to the schema, so product loading should be unaffected. However, please be aware that for customers using GeoPackage, no table for Routing Points is provided, and similarly for the vector tiles format, no layer is provided for Routing Points.

Next release

The next release of OS MasterMap Sites Layer is scheduled for April 2025.

OS MasterMap Sites Layer provides a nationally maintained view of the detailed extents of important locations such as airports, schools, hospitals, utility and infrastructure sites, and more. The points of access and routing points, to navigate in and out of the sites, are also provided.

All the source data that is used in the creation of has information about its function or purpose, and the Sites Layer is intended to enhance analytical use of this information.

OS MasterMap Sites Layer features are a representation of what people see in the real world, where the common view of something (such as a school) is not the address, the main building or the playing fields, but is the site as a whole.

The features are derived from Ordnance Survey’s detailed data content; therefore, the classification and grouping of features is dependent upon the source data capture specification.

Purpose

Many customers want to be able to answer a simple question, for example, ‘How close is this school to something?’, ‘What would be affected in the event of an emergency?’ or ‘How much of this hospital would flood?’

OS MasterMap Sites Layer creates a way for customers to easily answer these questions. It helps customers start using Ordnance Survey’s large-scale data in a more analytical manner.

The provision of ‘form and function’ information in OS MasterMap Sites Layer for risk modelling, business analysis and informed decision-making enables the use of intelligence sourced from for applications such as data analytics. The product will help customers start the journey to a more analytical use of OS MasterMap Topography Layer and would provide closer integration with OS MasterMap Highways Network and AddressBase product families.

It is important to note that the OS MasterMap Sites Layer product does not indicate the definitive or legal extent, but rather the extent of usage or function.

Product applications

The following table outlines the potential benefits of OS MasterMap Sites Layer for different customer groups:

Product update schedule

The product data is maintained alongside other Ordnance Survey large-scale content in an integrated edit environment. This will ensure that any relevant real-world change is updated in all relevant OS MasterMap Layers at the same time.

The product is updated every six months (April and October) as a full supply only.

This release note provides information about the October 2024 release of OS MasterMap Sites Layer.

This release note provides information about the April 2024 release of OS MasterMap Sites Layer.

These instructions are based on FME Desktop version 2021.1.

Loading and displaying the GML supply

To load and display GML data in FME Desktop:

1. Open an existing workspace or create a new one.

2. In Readers, click Add Reader.

1. In the Add Reader dialog:

   • Format: Select OGC GML (Geography Markup Language).

   • Dataset: Click …, navigate to and select the GML file on your computer.

   • Coord. System: Optionally, select EPSG:27700. FME should detect the correct system automatically.

   • Click OK.
2. In the Select Feature Types dialog, select the layers (feature types) you want to load and click OK.

A set of readers (matching the feature types your selected) displays in the main work area.

1. Right-click a reader and click Connect Inspector.

An inspector automatically connects to the reader.

1. Click the green Run To This icon (triangle above the inspector) and then click Run in the Translation Parameter Values dialog.

A table and graphical preview of the GML data displays below the main work area when the Run command completes.

1. Repeat steps 5 and 6 for each layer (feature type).

Converting GML to shapefile

You can use FME to convert GML data to other geospatial and non-spatial formats. The instructions below demonstrate how to convert to shapefile, but you can adapt them for different formats.

To convert GML to shapefile in FME Desktop:

1. Open an existing workspace or create a new one.

2. In Readers, click Add Reader…

1. In the Add Reader dialog:

   • Format: Select OGC GML (Geography Markup Language).

   • Dataset: Click …, then navigate to and select the GML file on your computer.

   • Coord. System: Optionally, select EPSG:27700. FME should detect the correct system automatically.

   • Click OK.
2. In the Select Feature Types dialog, select the layers (feature types) you want to load and click OK.

A set of readers (matching the feature types you selected) displays in the main work area.

1. In Writers, click Add Writer…

1. In the Add Writer dialog:

   • Format: Select Esri Shapefile.

   • Dataset: Click …, then navigate to and select the folder in which you want to save your translated data.

   • Click OK.
2. In the Select Feature Types dialog, select the feature types (layers) you want to convert, and click OK.

• This dialog may take a while to load. You can watch the progress in the green bar at the bottom left of the FME UI.

A set of writers (matching the feature types you selected) displays in the main work area to the right of their matching readers.

1. Connect each reader to its matching writer by dragging the grey triangle on the reader to the red triangle on the writer.
2. Click the green arrow in the top bar to run the workspace.

1. In the Translation Parameter Values dialog, check that the source and destination file locations are correct and click Run.

You can watch the conversion progress in the Translation Log below the main work area.

When the conversion is complete, both the GML files and shapefiles will be available in the file system on your computer and in the FME Navigator panel.

These instructions are based on Cadcorp SIS Desktop version 9.0 and assume you have set the default coordinate reference system to British National Grid (EPSG 27700). The instructions are also valid for the free, read-only version, Cadcorp SIS Desktop Express.

Loading and displaying the GML supply

To load and display GML data in Cadcorp SIS Desktop:

1. Open an existing map or create a new one.

2. In Home, click Add Overlay.

3. In the Overlay Types dialog:

   • Files: Select File and click Next.
   • Navigate to and select the file on your computer and click Finish.

Your GML data now displays in both the Maps panel and map area. The data is un-styled and will look similar to the following image:

These instructions are based on QGIS version 3.22.4 and assume you have set the default coordinate reference system to British National Grid (EPSG 27700).

Loading and displaying the GML supply

To load and display GML data in QGIS:

1. Open an existing project or create a new one.

2. In Layer, click Add Layer > Add Vector Layer.
3. In the Data Source Manager dialog:

   • Vector > Source > Vector Dataset(s): Click …, navigate to and select the GML file on your computer.

   • Click Add.
   • In the Select Items to Add dialog, select one or more site layers and click Add Layers.
4. Close Data Source Manager.

Your GML data now displays in both the Layers panel and map area. The data is un-styled and will look similar to the following image:

The sections that follow show you how to convert GML data to shapefile and how to apply a spatial index to shapefiles.

Converting GML to shapefile

To convert GML to shapefile in QGIS:

1. In the Layers panel, right-click on the layer you want to convert and click Export > Save Features As....
2. In the Save Vector Layer as… dialog:

   • Format: Select ESRI Shapefile.

   • File name: Click …, navigate to the folder in which you want to store the shapefile, name the file, and click Save.

   • Click OK.

When you click OK, QGIS creates a shapefile from the exported GML file and saves it to the selected folder.

1. Repeat steps 1 and 2 for each layer you want to convert. For example, for the other layers of the 5km² OS MasterMap Sites Layer data.

Applying a spatial index to shapefiles

When working with shapefiles, we recommend you apply a spatial index to the data, particularly when loading large or national sets of data. This significantly improves performance when rendering and panning the data.

To apply a spatial index to a shapefile in QGIS:

1. In the Layers panel, right-click on the layer you want to index and click Properties.
2. In the Layer Properties dialog:

   • Source > Geometry: Click Create Spatial Index and then click OK when the process is complete to close the success confirmation dialog.

   • Click OK.

These instructions are based on ArcMap version 10.8.1 and assume you have set the default coordinate reference system in ArcMap to British National Grid (EPSG 27700).

Loading and displaying the GML supply using the Quick Import tool

You can import GML data into ArcMap using the Quick Import tool. The imported data will be un-styled.

To load GML data in ArcMap:

1. In the top bar, click the ArcToolbox icon.

2. Expand Data Interoperability Tools and double-click Quick Import.
3. In the Quick Import dialog:

   • Input Dataset: Click … to open the Specify Data Source dialog:

     • Format: Select GML SF-0 (Geography Markup Language Simple Features Level SF-0 Profile).

     • Dataset: Click …, then navigate to and select the GML file on your computer.

     • Click OK.
   • Output Staging Geodatabase: Click the folder icon, navigate to and select the output folder on your computer.

   • Click OK.

The Quick Import tool creates a new geodatabase and imports the data into it.

To display the GML data in ArcMap:

1. Click Add Data in the tool bar.

1. In the Add Data dialog, select the file geodatabase (created in the previous procedure) on your computer and click Add.

Your GML data now displays in the Layers panel and map area. The data is un-styled and will look similar to the following example:

Loading and displaying shapefiles

As an alternative to using ArcMap’s Quick Import tool (previous section), you can convert your GML data to shapefile using QGIS or FME, and then add it directly to ArcMap. There are instructions on how to do this in previous sections of this guide.

To load and display shapefiles in ArcMap:

1. Open an existing project or create a new one.

2. In the top bar, click Add Data.

1. In the Add Data dialog, select the shapefile you want to load, and click Add.

1. Repeat steps 2 and 3 to load the additional shapefiles (AccessPoint and RoutingPoint) that make up each 5 km2 tile of OS MasterMap Sites Layer.

Your data now displays in the Layers panel and map area. The data is un-styled and will look similar to the following example:

Structure

This data specification works within the existing structure of OS MasterMap as represented in the Unified Modelling Language (UML) class diagram below:

Layers

A layer is a set of related geospatial data which is then divided into one or more themes (much like OS MasterMap Topography Layer). These themes can be used together to form an end-user application.

Themes

Features

Features are digital representations of real-world concepts such as a building, road or barrier. The life cycle of a feature, its creation, modification and deletion are managed to most appropriately reflect the life cycle of the abstracted real-world concept that they depict.

Attributes

An attribute is any item of information contained within an OS MasterMap feature. The TOID and the geometry of the feature are both attributes.

OS MasterMap Sites Layer provides a nationally consistent polygonised representation of areas or extents of particular function or activity, and which are attributed to best reflect that function. It also contains access points and routing points to navigate in and out of the captured sites. These access points reference the OS MasterMap Highways Network product for easy interoperability between the two products.

All the source data used in the creation of OS MasterMap Topography Layer contains insight about a site’s function or purpose, and the Sites Layer is intended to not only make this information available, but to enhance its analytical capabilities. OS MasterMap Sites Layer features are a representation of the boundary of real-world facilities, such as a school, where the site consists of more than an addressable main building.

The features are derived from Ordnance Survey’s highly detailed core data, and therefore the classification and grouping of features is dependent upon the source data capture specification. The product contains three feature types:

• Functional site polygons (FunctionalSite)

• Functional site access points (AccessPoint)

• Functional site routing points (RoutingPoint)

These three types are defined in this document in INSPIRE-compatible terms, with reference to the INSPIRE data specifications for facilities. The attribute naming convention also takes into consideration consistency with attribute names in other OS MasterMap layers and products.

It is important to note that the attribute naming has been carried over from the former OS MasterMap Integrated Transport Network (ITN) Layer. This has been done to minimise the impact of the implementation of OS MasterMap Highways Network.

The components that make up these features, and their relationships are shown in the product’s logical model diagram below.

Integration with other OS MasterMap layers

A main premise of the OS MasterMap product family is that layers of the differing products can be integrated with each other.

Layers are integrated by the sharing of common coordinate systems and contextual identifiers. Except for the Imagery Layer, the TOID feature identification attribute provides a unique feature-level reference that can be used to identify and track a feature between related OS MasterMap layers. For example, in OS MasterMap Sites Layer, there is an explicit link between the access point feature and the OS MasterMap Highways Network Layer road node that is closest to it.

Coordinate reference systems

Supply format

The OS MasterMap Sites Layer product is supplied in three different formats:

• Geography Markup Language (GML) version 3.2.1

• GeoPackage

• Vector tiles (MBTiles)

Index

The OS MasterMap Sites Layer technical specification contains the following sections:

You can use the Astun Technology Loader to convert GML 3.2.1 data to other geospatial and non- geospatial formats. This is a free, open-source loader for geographic data in GML and KML formats. It is written in Python and uses OGR 1.9. source data to output to any format supported by OGR, for example, shapefile and MapInfo TAB.

Installation files and guides for the loader, including configuration examples, are available from the AstunTechnology/Loader repository on GitHub.

Product feature types

The product contains three feature types:

• Functional site polygons (FunctionalSite)

• Functional site access points (AccessPoint)

• Functional site routing points (RoutingPoint)

Functional sites

A functional site is a polygon representing the area, or extent, of certain types of function or activity, with appropriate attribution. It gives information surrounding the functional theme of the site (for example, education), specific site function (for example, primary education), site name, site size, primary site Unique Property Reference Number (UPRN) and additional supporting attribution (for example, version date).

Functional site themes are discussed in more detail further into this section.

Access points

An access point is a point feature type that refers to the accepted/maintained locations where pedestrians and/or vehicles can enter or leave a site. It gives information associated with access type (for example, pedestrian), contains attribution that allows interoperability with other feature types (for example, reference to routing point) and additional supporting attribution (for example, version date).

Routing points*

A routing point is a point feature type that refers to a position on the OS MasterMap Highways ‘road link’ feature that is close to a functional site access point. It can be used to aid vehicle navigation to the access point of the functional site via the OS MasterMap Highways Network. It also gives additional supporting attribution such as ‘version date’ and ‘start distance’.

*To meet customer needs a fully routable modal network is being created. A key element of this is to provide more usable data about the access to destinations. As a result, we are now directly splitting our road, track and path data where Access Links connect to the network. This will allow users to more easily route into sites using OS network data.

As nodes have now been created within the networks data, where Access Link features connect, there is now no requirement for Decision Node features and they are being removed from the Sites products.

This section describes the themes that are included in OS MasterMap Sites Layer and lists examples of functional sites that are represented within these.

Theme definitions

Air transport

This theme includes sites associated with the movement of passengers and goods by air, or where aircraft take off and land.

Examples: airfield, airport, heliport.

Education

This theme includes a very broad group of sites with a common high-level primary function of providing education (either state-funded or by fees).

Examples: non-state primary education, special needs education and higher or university education.

Medical care

This theme includes sites that focus on the provision of secondary medical care services.

Examples: hospice, hospital and medical care accommodation.

Rail transport

This theme includes sites associated with the movement of passengers and goods by rail.

Examples: railway stations, vehicular rail terminals and tram stations.

Road transport

This theme includes sites associated with the movement of passengers and goods by road.

Examples: bus stations, coach stations and road user services.

Water transport

This theme includes sites involved in the transfer of passengers or goods onto vessels for transport across water.

Examples: vehicular ferry terminal and passenger ferry terminal.

Utility or industrial

This theme includes sites where the following activities take place:

• The principles of chemistry are applied to materials to create different materials on a large scale

• Energy (that is, electricity, gas or oil) is produced, refined, distributed or stored

Examples: chemical works, oil terminal and gas distribution or storage.

Styling

A sample style for the graphical depiction of the functional site extents, access and routing points has been designed to aid customers with illustrating this product. Ordnance Survey has created Style Layer Descriptors (SLD); these can be found on GitHub.

This getting started guide shows you how to load the GML supply of the OS MasterMap Sites Layer into several commonly used geographical information system (GIS) applications.

Product supply and formats

OS MasterMap Sites Layer is supplied as an online download in the OS Data Hub.

You can order OS MasterMap Sites Layer data for either all of Great Britain or by 5 km² tile. In the 5 km² tiles, features are not clipped at tile edges, resulting in what is known as 'hairy' tiles.

The product is available in the following formats:

• GeoPackage

• Vector tiles (MBTiles)

• GML (3.2.1)

All formats contain three layers: Functional Site, Access Point, and Routing Point.

File naming conventions

The GML file naming conventions for OS MasterMap Sites Layer are:

National sets

National datasets are grouped into the seven themes within Sites Layer: air transport, education, medical care, rail transport, road transport, water transport, and utility and industrial.

File names follow this pattern: <product>_<theme>_<area>.gz, for example, osmmsites_airt_england.gz.

Tiled data

Tiled datasets are provided in 5 km² tiles. Each tile includes all themes present in that tile. Files names follow this pattern: <5k tile ID>.gz, for example, HP5000.gz.

Using GeoPackage and vector tile formats

This theme includes sites associated with movement of passengers and goods by air, or where aircraft take off and land.

All active air transport features (including military sites) will be captured as indicated below unless they fall out of scope (for example, a private property) or are described as disused sites.

The following features are included in the captured extent:

• Buildings for the handling of air passengers and goods.

• Buildings for the storage and maintenance of aircraft.

• Aircraft landing and taxiing surfaces (man-made or natural).

• Site access roads and paths.

• Structures associated with the operation of the site.

• Car parks for air passengers.

• Areas of man-made and natural surface totally surrounded by included areas.

• Areas of man-made and natural surface abutting included areas along a non-obstructing edge.

The following features are not included in the captured extent:

• Aircraft-related services outside of perimeter fence (for example, warehouses or catering).

• Public through-roads and pavements.

• Hotels adjacent to site and their car parks.

This theme includes a very broad group of sites with a common high-level primary function of providing education (either state-funded or fee-paying).

The table above shows how the main function of a site has been mapped across to the equivalent functional site attribution, for example, a first school will be attributed as ‘primary education’.

Where a school is described with one or more functions and it is not possible to ascertain which buildings relate to which function, the entire site will be captured once for each function present. There will also be instances where there are several functions associated to a single site.

In some cases, it may be possible to determine which buildings are related to the different functional sites, but not possible to divide the playing fields; as a result, the playing fields will be captured for each function and will overlap.

The following features are included in the captured extent:

• All teaching and assembly buildings supporting education functions.

• Ancillary buildings and structures directly enabling the site to operate (for example, boiler house, kitchens and waste disposal areas).

• Site access roads and paths.

• Recreational areas associated with the site (for example, playgrounds and playing fields).

• Areas of man-made and natural surface totally surrounded by included areas.

• For schools: areas of man-made and natural surface abutting included areas along a non-obstructing edge.

The following features are not included in the captured extent:

• Public roads and pavements.

• Pedestrian through-routes.

• Separately addressed properties as indicated by house numbers.

Universities or higher education sites that have extensive and regionally disparate sites will be associated together using the stakeholder attribute, to specify a relationship between such sites that come under the control of a single stakeholder. This attribute is currently not populated but will be implemented in subsequent releases of the product.

Sites associated with professional bodies or work places will not be captured, for example, ‘Dance School’ or ‘Performing Arts School’.

This theme includes sites that focus on the provision of secondary medical care services.

All medical care sites will be captured as indicated below unless they fall out of scope; for example, a private property labelled as ‘The Blue Hospital’.

The following features are included in the captured extent:

• Main buildings.

• Site-specific service buildings and structures.

• Access roads and paths.

• Site-specific car parks.

• Areas of man-made and natural surface surrounded by included areas.

The following features are not included in the captured extent:

• Buildings not specifically related to the operation of the site (for example, children’s nursery).

• Public through-roads and their pavements; and public pedestrian through-routes.

These instructions are based on MapInfo Professional version 16.0 and assume you have set the default coordinate reference system to British National Grid (EPSG 27700).

The sub-sections below provide alternative instructions for working with GML data in MapInfo Professional.

Loading and displaying the GML supply

To load and display the GML supply directly into MapInfo Professional:

1. Open an existing project or create a new one.

2. In Home, click Open > Universal Data.

1. In the Specify Data Source dialog:

   • Format: Select GML (Geography Markup Language).

   • Dataset: Click …, navigate to and select the GML file on your computer.

   • Click OK.

1. In the Select Layers dialog, select the layers you want to load, and click OK.

Your GML data now displays in the Maps panel and map area. The data is un-styled and will look similar to the following example:

Converting GML to MapInfo TAB

To convert the GML supply to MapInfo TAB in MapInfo Professional:

1. Open an existing project or create a new one.

2. In Table click Universal Translator.

1. In the FME Quick Translator dialog click Translate.

1. In the Set Translation Parameters dialog:

   • Reader:

     • Format: Select GML (Geography Markup Language).

     • Dataset: Click …, navigate to and select the GML file on your computer.

   • Writer:

     • Format: Select MapInfo TAB (MAPINFO).

     • Dataset: Click …, navigate to and select the folder in which to store your TAB files.

   • Click OK.

1. When the conversion is complete (about 30 seconds), close the FME Quick Translator dialog.

To load the converted MapInfo TAB files in MapInfo Professional:

1. In Home click Open > Table.

1. In the browser dialog, select MapInfo (*.tab) as the file type, navigate to the folder in which you stored the converted MapInfo TAB files, select the layers you want to open, and click Open.

Your data now displays in the Maps panel and map area. The data is un-styled and will look similar to the following example:

A theme is a set of features that have been grouped together for the convenience of customers and to provide a high-level means of dividing the data in the layer logically. Features belong to only one theme.

Below are descriptions of the themes that are currently included in OS MasterMap Sites Layer and examples of functional sites that are represented within these themes. Also provided is an explanation of the features included or excluded during the capture process of an extent.

OS MasterMap Sites Layer provides seven themes:

• Air transport

• Education

• Medical care

• Rail transport

• Water transport

• Utility or industrial

This theme includes sites associated with movement of passengers and goods by rail.

All rail transport sites will be captured as indicated below unless they fall out of scope; for example, a private property labelled as ‘Railway Station Bungalow’.

The following features are included in the captured extent:

• Station buildings

• Station shelters

• Platform areas

• Access roads and paths

• Station footbridges and associated structures

• Station car parks

• Areas of man-made and natural surface surrounded by included areas

• Areas of man-made and natural surface abutting included areas along a non-obstructing edge The following features are not included in the captured extent:

• Railway buildings (for example, signal boxes and maintenance huts)

• Railway track areas (made-way)

• Man-made and natural areas alongside tracks

• Public roads and footpaths

It is important to note that functional sites in the rail transport theme are often not contiguous and may be constrained of the structure of polygons in the Topography Layer.

This theme includes sites involved in the transfer of passengers or goods onto vessels for transport across water.

The following features are included in the captured extent:

• Port buildings (for example, customs office, ticket office, waiting room)

• Vehicle parking/waiting areas

• Structures for loading people, vehicles or goods onto vessels

• Access roads and paths

• Areas of man-made and natural surface surrounded by included areas The following features are not included in the captured extent:

• Public roads and pavements

A functional site is a geolocated polygon representing the extent encompassing features with a collective type of function or activity. The functional site is thematically attributed and accompanied by access points. All the source data used in the creation of the OS MasterMap Topography Layer contains information about a feature’s function or purpose. Much of this data has been exposed in the Functional Sites Layer as a means of enhancing its analytical functionality. Functional sites are a representation of an assembly of cartographic features that share a common function (such as a school). It could also be a contiguous collection of features; for example, ‘General Hospital’.

Functional sites are created using the base form and function attributes of topographic areas. Information, such as ownership is not included within those attributes and cannot be used to ascertain extent. Because of this, functional site extents should not be confused with, or applied as legal extents.

A functional site can have multiple functions, or they can share some topographical features with another functional site. Shared topographic features, such as a sports field shared by two schools, will have the field captured to both school functional sites. Should there be a sports club on the grounds, such as a football club, then the field will be captured to this as well.

Rules have been developed for defining the differing types of functional site based on their function and the Topographic features that are visible from aerial photography. These rules specify what area features will be included within a functional site and how the boundary extent of the site can be delineated.

For example, the figure below demonstrates the extent of a simple functional site using OS MasterMap Topography Layer area features to identify and capture its extent. This is done by assessing a group of features that appear within a recognisable obstructing boundary and assigning them to the same functional site. This is also ratified using stereo aerial imagery and investigation through Change Intelligence. In the example shown below, this methodology has been used to assign all the features within the fence to a common function, in this case, a gas hub.

Each functional site has its own unique TOID and will be maintained throughout its lifecycle including versioning, changes and updates to its component features and alterations to its extent should they be warranted (for instance if the site increases in size due to land purchase). In addition, private roads that are wholly contained within a functional site and support the function are included in the extent.

It is important to note that obscured and underground features are not captured. This is because the OS MasterMap Topography Layer is captured at ground level from what is visible by aerial photography. However, all above ground features will be captured as normal.

While typically a functional site will usually be a connecting collection of polygons from OS MasterMap Topography layer, it is also possible for the functional site to consist of one or more disparate extents. Some sites, such as university campuses, will be a collection of several functional site extents belonging to a single stakeholder. These will be captured as one or more functional sites depending on the distance between the captured extents.

The stakeholder name will be captured if it is clear and unambiguous and is obtained through investigation where possible. The primary use of the stakeholder attribute is to define extensive and widely dispersed sites that come under the control of a single stakeholder; for example, universities.

In instances where multiple stakeholders exist for a given site, they will be listed in alphabetical order in the Stakeholder 1 attribute. Each new stakeholder will be separated with ‘+’. The Stakeholder 1 attribute will continue to hold only one role. The Stakeholder 2 attribute and role should not be populated.

The attributes currently not populated have been greyed out in the attribute definitions table in the following section.

This theme includes sites associated with the movement of passengers and goods by road.

All road transport sites will be captured as indicated below unless they fall out of scope (for example, a private property).

The following features are included in the captured extent:

• Bus/coach station buildings (for example, ticket office, waiting room)

• Bus/coach station shelters

• Car/bus/coach parking areas

• Buildings for bus/coach storage, maintenance and cleaning

• Access roads and paths

• Areas of man-made and natural surface surrounded by included areas The following features are not included in the captured extent:

• Public roads and pavements

• Pedestrian through-routes

This section defines the attributes associated with the RoutingPoint feature. It is important to note that UML notation has been used to show the multiplicity for an attribute. These indicate whether an attribute is optional (0), has a single value (1), or can have either / or (0..1) where ‘or’ is represented by double dots (..).

RoutingPoint attributes

RoutingPoint

Subtype of: Node, TransportNode

The spatial object type defining point/node feature, which would normally lie on a Highways RoadLink and would be referenced by a particular access point.

geometry

The coordinate geometry defining the position of the routingPoint. The geometry is projected in two-dimensions (2D).

• Attribute Name: geometry

• Value type: GM_Point

• Size: One coordinate set

• Multiplicity: [1]

toid

A unique identifier for a routingPoint, which is maintained along with the version number and version date to reflect the life cycle of the feature. NOTE: equivalent to INSPIRE identifier.

• Attribute Name: toid

• Value type: Text

• Size: 20

• Multiplicity: [1]

version

The version number of the data representation of the persisting routingPoint feature.

• Attribute Name: version

• Value type: Integer

• Size: 3

• Multiplicity: [1]

versionDate

The date on which the current version of the routingPoint was created.

• Attribute Name: versionDate

• Value type: Date

• Size: NA

• Multiplicity: [1]

reasonForChange

Reason for the current version of the routingPoint to be created. The valid reasons for change are defined in the ReasonForChangeValue code list.

• Attribute Name: reasonForChange

• Value type: ReasonForChangeValue

• Size: 20

• Multiplicity: [1]

refToITNRoadLink

The unique identifier (TOID) of the Highways road link feature that the routingPoint is related to.

• Attribute Name: refToITNRoadLink

• Value type: Text

• Size: 20

• Multiplicity: [1]

itnRoadLinkVersionDate

The date on which the current version of the Highways Road Link was created. A default value of ‘1900-01-01’ will be used to indicate where the date of this feature has not been captured.

• Attribute Name: itnRoadLinkVersionDate

• Value type: Date

• Size: NA

• Multiplicity: [1]

startDistance

The distance (m) from the start of the referenced Network RoadLink feature to the vertex where the RoutingPoint is positioned. The startDistance is calculated in two-dimensions (2D).

• Attribute Name: startDistance

• Value type: Length

• Size: 7.2

• Multiplicity: [1]

This section defines and describes the values that are used by the product attributes to describe the functional site, access point, and routing point features. There are some attribute values currently not populated in OS MasterMap Sites Layer. These features are listed below the tables they feature in.

This section defines the attributes associated with the FunctionalSite feature. It is important to note that UML notation has been used to show the multiplicity for an attribute. These indicate whether an attribute is optional (0), has a single value (1), or can have either/or (0..1) where ‘or’ is represented by double dots (..).

FunctionalSite attributes

Subtype of: ActivityComplex Feature

A spatial area object that describes the geometry, extent and function of a real-world feature.

geometry

The coordinate geometry defining the area of the functionalSite. This relates to multi-part geometry. The geometry is projected in two dimensions (2D).

• Attribute Name: geometry

• Value type: GM_Object

• Size: Minimum of 3 vertices

• Multiplicity: [1]

toid

A unique identifier for a functionalSite that is maintained along with the version number and version date to reflect the life cycle of the feature. NOTE: equivalent to INSPIRE identifier.

• Attribute Name: toid

• Value type: Text

• Size: 20

• Multiplicity: [1]

version

The version number of the data representation of the persisting functionalSite feature.

• Attribute Name: version

• Value type: Integer

• Size: 3

• Multiplicity: [1]

versionDate

The date on which the current version of the functionalSite was created.

• Attribute Name: versionDate

• Value type: Date

• Size: NA

• Multiplicity: [1]

reasonForChange

Reason for the current version of the functionalSite to be created. The valid reasons for change are defined in the ReasonForChangeValue code list.

• Attribute Name: reasonForChange

• Value type: ReasonForChangeValue

• Size: NA

• Multiplicity: [1]

functionStatus

This refers to the INSPIRE Activity Complex Status. This refers to a description of the state of a functionalSite. The valid states are defined in the FunctionStatusValue code list.

• Attribute Name: functionStatus

• Value type: FunctionStatusValue

• Size: NA

• Multiplicity: [1]

functionTheme

A description of the theme that a particular site falls under (that is, air transport, education, medical care and so on). The valid themes are defined in the FunctionThemeValue code list.

• Attribute Name: functionTheme

• Value type: FunctionThemeValue

• Size: NA

• Multiplicity: [1]

function

A description of the actual function of a site (that is, airfield, junior school, hospital and so on). The valid themes are defined in the FunctionValue code list. For sites with multiple functions, the values will be provided together and separated by a ‘,’. Valid multiple functions are described in the Function combination table.

• Attribute Name: function

• Value type: FunctionValue

• Size: NA

• Multiplicity: [1]

perimeter

The perimeter (m) of the site or sum of the sites for a non-contiguous feature. The perimeter is projected in two dimensions (2D).

• Attribute Name: perimeter

• Value type: Length

• Size: 10.2

• Multiplicity: [1]

area

The area (m2) of the site or sum of the sites for a non-contiguous feature. The area is projected in two dimensions (2D).

• Attribute Name: area

• Value type: Real

• Size: 16.6

• Multiplicity: [1]

distinctiveName1

The name of the site (for example, ‘Brighton College’). Note this may be null if the captured value is a house number.

• Attribute Name: distinctiveName1

• Value type: Text

• Size: 99

• Multiplicity: [0..1]

distinctiveName2

A second name of the site, if applicable. Note this may be null if the captured value is a house number.

• Attribute Name: distinctiveName2

• Value type: Text

• Size: 99

• Multiplicity: [0..1]

distinctiveName3

A third name of the site, if applicable. Note this may be null if the captured value is a house number.

• Attribute Name: distinctiveName3

• Value type: Text

• Size: 99

• Multiplicity: [0..1]

distinctiveName4

A fourth name of the site, if applicable. Note this may be null if the captured value is a house number.

• Attribute Name: distinctiveName4

• Value type: Text

• Size: 99

• Multiplicity: [0..1]

primaryAddressBaseUPRN

Unique Property Reference Number (UPRN) assigned by the local custodian or Ordnance Survey to the primary building within a functional site (for example, main building in a school).

• Attribute Name: primaryAddressBaseUPRN

• Value type: Integer

• Size: 12

• Multiplicity: [0..1]

stakeholder1

Information on parties related to the functionalSite. It is open to many different roles, such as owners, operators or competent authorities. Where more than one stakeholder exists, this field contains multiple stakeholders separated by ‘ + ‘.

• Attribute Name: stakeholder1

• Value type: Text

• Size: 99

• Multiplicity: [0..1]

stakeholder2

Information on parties related to the functionalSite. It is open to many different roles, such as owners, operators or competent authorities. Currently not populated.

• Attribute Name: stakeholder2

• Value type: Text

• Size: 99

• Multiplicity: [0..1]

stakeholder1Role

Information on the different roles of stakeholders for a particular functionalSite, such as users, owners, operators or competent authorities. The valid roles are defined in the StakeholderRoleValue code list.

• Attribute Name: stakeholder1Role

• Value type: StakeholderRoleValue

• Size: NA

• Multiplicity: [0..1]

stakeholder2Role

Information on the different roles of stakeholders for a particular functionalSite, such as users, owners, operators or competent authorities. The valid roles are defined in the StakeholderRoleValue code list. Currently not populated.

• Attribute Name: stakeholder2Role

• Value type: StakeholderRoleValue

• Size: NA

• Multiplicity: [0..1]

extentDefinition

This describes the nature of the defined extent of the functionalSite at the time of capture. The valid roles are defined in the ExtentDefinitionValue code list.

• Attribute Name: extentDefinition

• Value type: ExtentDefinitionValue

• Size: 20

• Multiplicity: [1]

This theme includes sites where the following activities take place:

• The principles of chemistry are applied to materials to create different materials on a large scale.

• Energy (that is, electricity, gas or oil) is produced, refined, distributed or stored.

The following features are included in the captured extent:

• Internal site access roads and paths.

• Buildings and structures associated with the operation of the site.

• Areas of man-made and natural surface totally surrounded by included areas.

• Areas of man-made and natural surface abutting included areas along a non-obstructing edge.

For marine oil terminals, include related berthing structures physically connected to the site The following features are not included in the captured extent:

• Site-related areas outside of perimeter fence (for example, car parking).

• Isolated mooring structures.

The OS MasterMap Sites Layer data model is designed to integrate with OS MasterMap Highways Network. Routing points are intended to provide users with a reference to the position that is close to an access point, which can be used to aid navigation to the access point via the Highways road network. The routing points are provided where there is no viable Highways Network road node feature to refer to directly from an access point.

Routing points are currently being created by an automated process that performs a spatial query to identify the nearest position on the closest Highways Network road link feature. The process also ensures that there is no viable road node on the selected road link using a 5-metre tolerance before generating a routing point.

Routing points supplied in the initial release of OS MasterMap Sites Layer are created from the

OS MasterMap Highways Network – Roads product but still reference the ITN road network. In addition to the OS MasterMap Highways Network – Roads data, we have applied OS MasterMap Highways Network – Paths data.

The process will be subject to continuous revision between releases to improve its results.

FunctionalSite feature

Defines the values for the different states that a functional site may have. This generally refers to the condition of the functional site.

FunctionalSite feature

Defines the values for the different roles that stakeholders for a particular site may have. This will evolve with changes to the capture specification.

AccessPoint feature

Defines the values of the possible nature of the access permitted at the access point.

An access point refers to a functionally designed and maintained location where pedestrians and/or vehicles can enter or leave a site. Access points are initially captured from a visual inspection of OS MasterMap Topography and Imagery Layers. Further access points can also be captured and maintained through customer feedback and field survey.

Access points are point features which have been positioned on the boundary of the functional site extent to which they belong (see figure below). There are circumstances where access points do not lie on the site boundary; for example, underground or obscured access into a site, and these will be captured in their true position or within five metres of the functional site extent boundary.

Where there are several access types that are located next to each other; for example, a road with a pavement on one or more sides, a single ‘combined access’ point will be created to indicate that it is possible to access the site by foot and by vehicle at that location.

Access points are linked to functional site extents during their capture. They can also retain additional access information such as height and time or vehicular restrictions. The access point also references the nearest OS Highways Network Layer link TOID. This allows the user to easily integrate the data with other OS Datasets such as the OS MasterMap Highways Network Layer.

Each access point will have its own unique TOID and will be subject to a managed life cycle process, controlled by changes to attributes as well as changes to its associated Functional Site’s attributes.

Some of the access points have restrictions which cannot be ascertained from aerial imagery. As such, they are not currently available in OS MasterMap Sites Layer. The attributes currently not populated have been greyed out in the attribute definitions table in the following section.

FunctionalSite feature

Defines the values for the nature of extent that a particular site may have.

This section defines and describes the values that are used by the product attributes to describe the functional site, access point, and routing point features. There are some attribute values currently not populated in OS MasterMap Sites Layer. These features are listed below the tables they feature in.

This section defines the attributes associated with the AccessPoint feature. It is important to note that UML notation has been used to show the multiplicity for an attribute. These indicate whether an attribute is optional (0), has a single value (1), or can have either/or (0..1) where ‘or’ is represented by double dots (..).

AccessPoint attributes

AccessPoint

Subtype of: Node, TransportNode

The spatial object type defining a point where there is access into and/or out of a site.

geometry

The coordinate geometry defining the position of the accessPoint. The geometry is projected in two dimensions (2D).

• Attribute Name: geometry

• Value type: GM_Point

• Size: One coordinate set

• Multiplicity: [1]

toid

A unique identifier for an accessPoint, which is maintained along with the version number and version date to reflect the life cycle of the feature. NOTE: equivalent to INSPIRE identifier.

• Attribute Name: toid

• Value type: Text

• Size: 20

• Multiplicity: [1]

version

The version number of the data representation of the persisting accessPoint feature.

• Attribute Name: version

• Value type: Integer

• Size: 3

• Multiplicity: [1]

versionDate

The date on which the current version of the accessPoint was created.

• Attribute Name: versionDate

• Value type: Date

• Size: NA

• Multiplicity: [1]

reasonForChange

Reason for the current version of the accessPoint to be created. The valid reasons for change are defined in the ReasonForChangeValue code list.

• Attribute Name: reasonForChange

• Value type: ReasonForChangeValue

• Size: NA

• Multiplicity: [1]

refToFunctionalSite

The unique identifier (TOID) of the functional site to which the accessPoint relates.

• Attribute Name: refToFunctionalSite

• Value type: Text

• Size: 20

• Multiplicity: [1]

accessType

This describes the nature of the access permitted at the accessPoint. The valid access types are defined in the AccessTypeValue code list. Where there is more than one type of access, the values will be provided together and separated by a ‘,’. Currently only Pedestrian and Motor Vehicles access types are populated.

• Attribute Name: accessType

• Value type: AccessTypeValue

• Size: 30

• Multiplicity: [1]

accessMechanism

This describes the mechanism used to access the functional site through the accessPoint. The valid AccessMechanismValue are defined in the AccessMechanismValue code list. Where there is more than one type of access mechanism, the values will be provided together and separated by a ‘,’. Currently not populated.

• Attribute Name: accessMechanism

• Value type: AccessMechanismValue

• Size: NA

• Multiplicity: [0..1]

accessDirection

This refers to the direction of travel that is permitted through the accessPoint. The valid access direction values are defined in the AccessDirectionValue code list. Currently not populated.

• Attribute Name: accessDirection

• Value type: AccessDirectionValue

• Size: NA

• Multiplicity: [0..1]

accessUseRestriction

This refers to the nature of any access restriction. The valid restrictions are defined in the AccessUseRestrictionValue code list. Where there is more than one type of restriction, the values will be provided together and separated by a ‘,’. Currently not populated.

• Attribute Name: accessUseRestriction

• Value type: AccessUseRestrictionValue

• Size: NA

• Multiplicity: [0..1]

refToRoutingPoint

The unique identifier (TOID) of the related routingPoint feature, if there is one.

• Attribute Name: refToRoutingPoint

• Value type: Text

• Size: 20

• Multiplicity: [0..1]

refToITNRoadNode

The unique identifier (TOID) of the related OS MasterMap Network Layer road node feature; if this is used rather than a routing point. The Network layers road node is used in an identical manner to that of the previous OSMM ITN version.

• Attribute Name: refToITNRoadNode

• Value type: Text

• Size: 20

• Multiplicity: [0..1]

itnRoadNodeVersionDate

The date on which the current version of the OS MasterMap Highways Network Layer road node was created. A default value of ‘1900-01-01’ will be used to indicate where the date of this feature has not been captured. The Network layers road node is used in an identical manner to that of the previous OSMM ITN version.

• Attribute Name: itnRoadNodeVersionDate

• Value type: Date

• Size: NA

• Multiplicity: [0..1]

dateTimeQualifier

This refers to the dates or times that access is permitted through the accessPoint.

• Attribute Name: dateTimeQualifier

• Value type: Text

• Size: 20

• Multiplicity: [0..1]

heightQualifier

This refers to the maximum vehicle height that is permitted through the accessPoint.

• Attribute Name: heightQualifier

• Value type: Distance

• Size: 4.2

• Multiplicity: [0..1]

widthQualifier

This refers to the maximum vehicle width that is permitted through the accessPoint.

• Attribute Name: widthQualifier

• Value type: Distance

• Size: 4.2

• Multiplicity: [0..1]

weightQualifier

This refers to the maximum vehicle weight that is permitted through the accessPoint.

• Attribute Name: weightQualifier

• Value type: Real

• Size: 4.2

• Multiplicity: [0..1]

lengthQualifier

This refers to the maximum vehicle length that is permitted through the accessPoint.

• Attribute Name: lengthQualifier

• Value type: Distance

• Size: 4.2

• Multiplicity: [0..1]

natureOfAccess

This describes the physical form of enforcement to expect at the accessPoint. The valid nature of access values is defined in the NatureOfAccessValue code list. Where there is more than one nature of access, the values will be provided together and separated by a ‘,’. Currently populated as Unknown.

• Attribute Name: natureOfAccess

• Value type: NatureOfAccessValue

• Size: NA

• Multiplicity: [1]

GML is an XML (Extensible Mark-up Language) grammar for expressing geographic features. GML serves as a modelling language for geographic systems as well as an open interchange format for geographic transactions on the Internet.

• More information can be found on the Open Geospatial Consortium (OGC): http://www.opengeospatial.org/standards/gml.

• The XML specifications that GML is based on are available from the World Wide Web Consortium (W3C): http://www.w3.org.

• Information about Unicode and UTF-8, the character encoding we have chosen, is available on the Unicode Consortium website: http://www.unicode.org.

XML schema

XML schemas are used to validate the format and content of the GML. The GML 3.2.1 specification provides a set of schemas that define the GML feature constructs and geometric types. These are designed to be used as a basis for building application-specific schemas, which define the data content.

The Ordnance Survey application schemas that are referenced by the data are available from our website at: http://www.ordnancesurvey.co.uk/xml/schema.

These schemas make use of XML Schema Definitions (XSDs) and Document Type Definitions (DTDs) produced by the W3C that are available from the W3C website at: http://www.w3.org/XML/1998/namespace.html.

Namespaces

xlink – http://www.w3.org/1999/xlink

gml – http://www.opengis.net/gml

osgb – http://www.ordnancesurvey.co.uk/xml/namespaces/osgb

xml – http://www.w3.org/XML/1998/namespace

AccessPoint feature

Defines the values of the nature of any access restriction.

RoutingPoint feature

The ‘reasonForChange’ attribute is used across all features found within the OS MasterMap Sites Layer.

Defines the reason for a change made to a feature.

FunctionalSite feature

Defines the values for the different functional site themes captured in the data.

More details on each code can be found on the theme definitions page.

This will evolve with changes to the capture specification.

AccessPoint feature

Defines the values of the form of enforcement to expect at the access point.

FunctionalSite feature

Defines the values of the possible functions of a site.

Valid function (attribute) combinations

This section defines the geometric data types used by features of the OS MasterMap Sites Layer. A UML diagram is used to support the data type descriptions.

Features and spatial data types

The following table details the data type of the geometric attributes of OS MasterMap Site Layer features. Each feature type has a spatial attribute called ‘geometry’. The data type of this attribute is given in the third column of the table.

Geometric data types

Point

A point is used to specify a single horizontal location by a coordinate pair in a given spatial reference system.

Example

A point defined in the BNG reference system has easting and northing coordinates in units of metres, where the easting is in the range 0 to 700000 and the northing is in the range 0 to 1300000.

Example class model

Polygon

A polygon is a single closed region on the spatial reference system projection plane, defined by a set of geometric rings that represent the boundaries. A polygon has one outer boundary and zero or more inner boundaries (holes in the polygon). The inner boundaries must not cross each other or contain other inner boundaries. Coordinates in outer boundaries are oriented in an anticlockwise direction; coordinates in inner boundaries are oriented in a clockwise direction. In the Geography Markup Language (GML) data, these are implemented as a Surface containing a single Polygon Patch, with the exterior and any interior boundaries represented as a LinearRing.

Example

Example class model

Multi-polygon

A multi-polygon is used where a single functional site consists of separate areas, such as a school on both sides of a road. Each polygon is as described above. In GML, this is represented with a gml:MultiSurface having a number of ‘surface members’ each of which is a single gml:Surface.

AccessPoint feature

Defines the values for the possible mechanism of the access permitted at the access point.

AccessPoint feature

Describes the direction of travel that is permitted at the access point.

GeoPackage (*.gpkg) is an open, non-proprietary, platform-independent, standards-based data format for geographic information systems (GIS), as defined by the Open Geospatial Consortium (OGC). It is designed to be a lightweight format that can contain large amounts of varied and complex data in a single, easy to distribute and ready to use file. GeoPackage is natively supported by numerous software applications.

Attribute naming differences between GML and GeoPackage

The naming of attributes between GeoPackage and the Geography Markup Language (GML) file is very similar as GeoPackage files are not limited in the number of characters for an attribute name.

Therefore, the following tables map the GML attribute name to the attribute name in the GeoPackage files. The GML contains an attribute which describes the geometry of the feature; this is not applicable for a GeoPackage file as they are separated by their geometry.

Please note that the use of an asterisk symbol (*) in the following tables indicates that a particular attribute is not mapped to GML.

Stylesheets

Predefined stylesheets for OS MasterMap Sites Layer are available for download from the Ordnance Survey OSMM-Sites-stylesheets GitHub repository here.

• To download a ZIP containing all stylesheets, navigate to Code > Download ZIP.

OS MasterMap Sites Layer is supplied as a national vector tiles set in a single MBTiles file. This is a lightweight set of tiles that are efficient and fast to render in your software, and which provide high resolution data and give a seamless experience when zooming in and out. The data is supplied in Web Mercator projection (ESPG:3857).

Vector tiles schema

The vector tiles schema is detailed in the following table. In the zoom levels columns within the table, the letter N indicates that the specified layer and attribute are not mapped within that zoom level, whereas the letter Y indicates that the specified later and attribute are mapped within that zoom level.

Functional Site

Access Point

Routing Point