Frequently Asked Questions

What is the Irish Grid?

For a full explanation of the Irish Grid download the PDF document by clicking here.

What are large and small scale maps?

LPS produce a range of large and small scale mapping. Large scale mapping shows a lot of detail for a small area, such as a few streets. Small scale mapping shows a larger area but in less detail. The scale denotes the number of units on the ground that are represented by one unit on the map. For example, on a 1:1250 map, one unit on the map represents 1250 units on the ground. The scale required will depend on the nature of the task. A small scale map, such as the 1:50,000 Discoverer series which is aimed at general touring and leisure use will have been generalized, resulting in less detail. For example individual buildings will be grouped together as urban blocks, and road widths will be exaggerated so that they can be shown on the map. On a large scale map such as 1:1250, individual buildings will be shown to a high level of accuracy and measurements taken from the mapping will have a RMSE (root mean square error) of +/- 0.2 metres. Therefore if a high level of accuracy is important, then larger scale mapping should be used.

What is the difference between a Vector and Raster Map?

Vector mapping represents geographic features as points, lines, and polygons. Attributes associated with the point, line and polygon features are contained in a linked table to enable interrogation of the data. Vector mapping is most suitable for use within a specialized GIS system.

OSNI raster maps are digital representations of its paper mapping products. A raster map is a static image displayed on screen which is suitable as background mapping. OSNI raster images are geo referenced so that they display in their correct geographic location when viewed in a GIS package. Each raster image is made up of a series of equally sized cells (or pixels) arranged in rows and columns.

What are the different formats of the files?

There are various types of file formats available for data downloaded from this website. Each product will have information on what formats they are available in. Below is a short description of the available formats and what popular programmes they are used for.

DWG is a file format used for storing two and three dimensional design data and metadata. It is the native format for several CAD packages including AutoCAD

DXF is another drawing file format and is used for AutoCAD.

Tif (Tagged Image File Format), is a file format for storing images. It is commonly used for image software.

ECW (Enhanced Compression Wavelet) is a proprietary wavelet compression image format optimized for aerial and satellite imagery

How long does it take to download a product?

The length of time it takes to download a map will depend on the size of the file being downloaded. Download Time should take between five and ten minutes.

What type of map do I need for planning applications and property conveyancing?

An AceMap, an Address Centered Extract Map, is required for planning applications and conveyancing. This can be found on our Create a Map page.

What are the shop opening times for Lincoln Buildings and Ballymena?

Opening hours are 9.30 am to 4.30 pm Monday to Thursday and 10.00 am to 4.30 pm Friday.

They can be contacted by the following details:

Land & Property Services
1st Floor, Lincoln Building
27-45 Great Victoria Street
MALONE LOWER
Belfast
BT2 7SL

Tel: 0300 200 7804
Fax: 028 9025 1659

and

Land & Property Services
Academy House
121A Broughshane Street
Town Parks
Ballymena
BT43 6HY

Tel: 028 2566 4724
E-mail: LPSBallymena.CIC@dfpni.gov.uk

How do I purchase additional copies of an AceMap?

Additional copies of an AceMap can only be purchased if the customer is receiving the order by post at £1.60 per copy. Alternatively a customer can purchase a single occasion licence to make legal copies of an Acemap. This licence is priced at £41.50.

Can I make copies of an AceMap?

Copies of an Acemap may only be made if it is for personal/internal use or if you have purchased a single occasion licence.

How do I purchase historical mapping and aerial photography?

Large scale historical mapping can be purchased via the website on our Digital Products page. Alternatively you can view and purchase historical mapping and aerial photography through the LPS Ordnance Survey Archive Department. They can be contacted on (028) 90255743.

I need to locate my property's legal Boundary. Can I see this on Ordnance Survey Mapping?

Land and Property Services Mapping does not depict legal property boundaries.

How do I find a grid reference for a particular area?

Grid references, also known as co-ordinates, for a particular area can be viewed in the bottom left hand corner of the website window, along the bottom toolbar. This can be achieved by hovering your mouse over your location in the map console screen. If you can not view the co-ordinates please try the following steps.

How to display coordinates in Status Bar of Internet Explorer 7

In Internet Explorer 7 – go to tools

Click on “Internet Options”
Click on the “Security Tab”
Click on “Custom Level”
Scroll to “Allow Status Bar Updates Via Script”
Click “Enable”
Click “OK” and “OK” again to close everything

You should see the co-ordinates in the status bar.
 

What do I do if the map does not show my property / If map is not up to date?

If your property does not appear on the map, or if you feel that the map is not up to date please contact us through a feedback form. Access to the feedback form is located along the bottom of the website screen.

I cannot see the preview of my chosen area.

Please ensure that the latest version of Java has been installed in the computer. If you have any further problems please report them through the feedback form at the bottom of the page, alternatively please contact our Helpdesk service on (028) 9038 8488 or (028) 9025 5774.

How do I know what date an orthophotograph has been taken?

To obtain the date that an orthophotograph has been taken please contact our Helpdesk service on (028) 9038 8488 or (028) 9025 5774.

How do I display OSNI Largescale vector data to the correct scale in AutoCAD?

Most AutoCAD users work with drawings where 1 unit = 1mm.  OSNI data is surveyed to a scale of 1 unit = 1metre.  Most problems can be solved by scaling OSNI dwg and dxf’s by 1000 in AutoCAD.