A map showing a postcode unit which is at risk from fluvial flooding, individual properties that are free from flood risk are outlined in red
Our clients often ask us what the main differences between property and postcode level data are. The two levels of granularity offer their own advantages and disadvantages. These should be examined thoroughly before deciding which type of dataset is right for your business. In this blog, we’ve distilled the key differences between the two options and discussed which might be the best choice for your organisation.
Q: What can property level information tell me that postcode level information cannot?
A: Property level information has the advantage of providing a detailed view of risk for specific properties. In the UK, the property level information originates from up to date Ordnance Survey address data which means that specific addresses can be searched for and then assessed for environmental hazards. From a systems perspective this is highly advantageous. Postcode level information provides a general view of risk to the area, making it less granular and less precise.
The below image shows a postcode unit in the south of England with a high flood risk. However, with access to property level information it can be seen that seven properties (outlined in red) in the postcode unit are not within flood risk areas. Property level information has the potential to open up new opportunities for businesses.

A map showing a postcode unit which is at risk from fluvial flooding, individual properties that are free from flood risk are outlined in red
Q: What are the advantages of using postcode level data instead of property level data?
A: Postcode level data can be advantageous if you have a limited budget as this option is a lower priced option than property level data; however it is worth mentioning that Address level data licencing is becoming far more flexible and amenable.
Postcode data is also generally quicker to load as the file size is smaller than the property level data.
An interesting advantage of postcode level data is that it can be used to identify geographical areas that may need further investigation or areas that are completely free from risk. This method makes postcode level data useful for an initial screen of risk to a property.
Q: How can I access property level data?
A: Property level data can be accessed via multiple mechanisms based on end user requirements; 1). Through an API, 2). it can be acquired in a .csv format which is shared through a file transfer protocol or 3). it can be accessed through online portals, such as Ambiental’s FloodScore Online. Each method of access has their own advantages and disadvantages, such as different licence structures (e.g. Transactional) and also data/ server requirements.
Q: How can postcode level data be accessed?
A: Postcode level data is usually supplied in a flat file .csv format. However, Ambiental is always happy to work with clients on a bespoke basis and supply the data in a format that best suits each individual business’ requirements.
Q: Is there a way of accessing property level perils data on a limited budget?
A: Yes! There are several actually. Instead of acquiring the complete property level database, data can be purchased based on a limited number of database ‘lookups’ or credits. These credits allow access to only the relevant number of property level data searches, with each property view constituting one credit. Property level data can be accessed on a transactional basis through systems such as Ambiental’s FloodScore Online portal or the FloodScore API.
An alternative option is to consider how many terminals/ users of the data are required for your organisation. Address data licencing has becoming more flexible in that you can licence the data based on just the number of users that will accessing the data. This makes the data cost far more amenable for smaller organisations, who then pay a fee reflective of their use as oppose to full ‘corporate’ level licence.
There are also options around ‘bound-policy’ pricing, which we are happy to discuss separately.
Q: What data is displayed at Postcode level?
A: Risk scores for each postcode unit in Great Britain and Northern Ireland can be calculated. These provide an indication of the risk to the geographical postcode area for different flood mechanisms (fluvial, surface water (Pluvial) and tidal flooding). Additional perils data on groundwater flooding risk, subsidence risk and crime (to name a few) are also available at postcode level.
Q: What information is shown at Property level?
A: Property level data can provide information on…
– The flood depths likely to affect a property
– The likely frequency of flooding
– The property’s proximity to flooding
– An individual 0 flood risk rating score
– Information on whether the property benefits from flood defences
– The geocoded location of a property
– Average Annual Loss values in pounds sterling
– Annual Damage Ratios
– Information regarding property characteristics
– An optional view of the risk of groundwater flooding
– Optional data on the likelihood of subsidence damage to the property
– Other property specific perils information
Q: Can a combination of postcode and property data be used to assess risk?
A: Yes most definitely. Postcode data can be used to provide an initial screen of the risks to a geographical area and then if the results are inconclusive, the specific property can then be investigated at the individual property level to ascertain a more granular view of the risk.
Q: How can I find out more information?
A: Regardless of your flood risk management requirements, Ambiental has a product to fit your needs. We provide data at postcode level, as well as highly granular property level data. We can supply these products in various formats and on flexible subscriptions, because we know that every business is different. If you’d like to discuss how postcode or property level data can assist you in your flood risk strategy, please contact us. One of our team would be happy to help.
About the Author
Angus Stevens is a Technical Liaison at Ambiental. His role is focused on assisting clients with technical queries in relation to Ambiental’s UK and Ireland product range. Angus is also involved in updating data assets and quality assurance. He has a BSc (hons) in Physical Geography from the University of Southampton.
