OS MasterMap Sites Layer

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. OS MasterMap Sites Layer features are a representation of what people see in the real world, where the common view of something is not the address (such as a school), the main building or the playing fields, but is the site as a whole. The points of access are also provided which can be used to navigate in and out of the sites.

Where do the features come from?

The features are derived from Ordnance Survey’s detailed data content; the classification and grouping of features is dependent upon the source data's capture specification. This is the same source data that is used in the creation of OS MasterMap Topography Layer and has information about its function or purpose. The Sites Layer is intended to enhance analytical use of this information.

The image above shows the OS MasterMap family of which OS MasterMap Sites Layer is one of the products.

Themes

The OS MasterMap Sites Layer groups features into seven themes each having both a functional site and at least one access point.

These themes are:

• Air transport
• Education
• Medical care
• Rail transport
• Road transport
• Water transport
• Utility or Industrial.

The site access points include a link to the OS MasterMap Highways Network product via the TOID (topographic identifier) as a unique reference, to the Road Node. This can be used to as part of a routing solution using access rather than a site centroid which gives greater accuracy.

This is shown in the image where the Access Point in OS MasterMap Sites Layer has the corresponding TOID to the OS MasterMap Highways Network road node which in this case ends in 4832.

Available formats for the product

OS MasterMap Sites Layer is supplied in three different formats:

• Geography Markup Language (GML) 3.2.1*

• GeoPackage

• Vector tiles (MBTiles)

*Note that the GML version differs from OS MasterMap Topography Layer.

OS MasterMap Sites Layer is made available using a web-based ordering system,  OS Data Hub ,  that allows customers to order their initial data supply and obtain price estimates as appropriate. When placing an order customers can view details of their holdings. The product is supplied as an online download.

File Sizes and Coverage

OS MasterMap Sites Layer is a national dataset and is maintained and supplied as 5km² tiles of data as an Area of Interest (AOI) or as Great Britain (GB) supply.

File size estimates can vary from about 2KB compressed to about 162KB (compressed) for tile supply. A full GB supply will be approximately 43MB 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 90MB zipped for GeoPackage, and 160MB zipped for vector tiles.

For more information on the GeoPackage and Vector Tiles please see links below to the Getting Started Guides.

•  OS MasterMap Sites Layer - Getting started with GeoPackage 
•  OS MasterMap Sites Layer - Getting started with Vector Tiles 

The OS MasterMap Sites Layer 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 OS MasterMap Sites Layer is updated every six months (April and October) as a full supply.

Change-Only Updates (COU) are not available for OS MasterMap Sites Layer.

A sample style for the graphical depiction of the functional site extents, and access 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 

For more information please have a look at:

OS MasterMap Sites Layer -  Technical Information 

•  OS MasterMap Sites Layer - Technical specification  The technical specification provides detailed technical information about the product. It is targeted at technical users and software developers.
•  OS MasterMap Sites Layer - Getting started guide 
•  OS MasterMap Sites Layer - Getting started with GeoPackage 
•  OS MasterMap Sites Layer - Getting started with Vector Tiles 

OS Products refresh dates -  OS products refresh dates