Large scale map tiles

Large-scale vector is produced from OSNI's large-scale digital database and is the most widely used OSNI product

Vector mapping is a digital representation of topographic map features with attributed points, lines and polygons. OSNI Large-scale vector product contains 190 feature types or levels, known as attributes.

Key features

  • complete coverage of Northern Ireland, with rural areas surveyed at 1:2,500 scale and built up urban areas surveyed at a more detailed scale of 1:1,250
  • contains height information including spot heights and bench marks - all heights are above mean sea level at Belfast
  • the rich topographical data model and structure allows interactive access to information on features and makes large-scale vector suitable for a wide range of spatial queries
  • other vector, raster and address data, including the user's own datasets, can be used to increase functionality for example vector mapping can be overlaid with orthophotography using suitable software
  • projection consistent with other OSNI mapping data
  • all data fixed on the Irish Grid and capable of transformation to other reference systems
  • supplied either as pre determined tiles or as a bespoke clip out centred on a site specific area

Technical Information

  • vector data format
  • represents the real world in an organised and consistent way, according to a logical series of rules
  • contains 17,335 individual tiles, each based on the original large-scale maps of Northern Ireland surveyed at either 1:1,250 or 1:2,500 scales
  • every tile is edge-matched across the whole country, enabling the build up of a complete coverage
  • information can be stored for each individual piece of geometry, enabling links to the user's own data
  • scale free, can be viewed at a range of zoom scales without any loss of clarity
  • available in a range of data formats: - NTF, DXF and DWG
  • ESRI GDB and MapInfo TAB formats available for full Northern Ireland coverage only
  • detail is being constantly updated by OSNI
  • typical file size per tile 1MB
  • area covered by 1:1250 tile x 0.4km
  • area covered by 1:2500 tile 1.2km x 0.8km
  • bespoke user-defined area available


  • spatial queries
  • geo-demographic analysis
  • distance and area measurement
  • property conveyancing
  • planning and resource management
  • land registration
  • generation of paper products and bespoke cartographic representation

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