The House Price Index (HPI) is a valuable tool for understanding how the average house price has changed over several decades.

https://www.gov.uk/government/statistical-data-sets/uk-house-price-index-data-downloads-june-2025

The current file size is just over 32MB, so not great, but not terrible.  Easy one to upload and manage.  

Provided under the Open Government License V3.0

It's a large dataset by field with 64 in total.

Along with the average price, you can break it down between:

• Regions →  England, Wales, Scotland and Northern Ireland.  So you can drill down into each Nation.
• Property type → Detached, Semi, Terraced and flat.
• AveragePrice → average property price (main headline figure).
• Index → HPI index (base = Jan 2015 = 100).
• IndexSA → seasonally adjusted index.
• 1m%Change → monthly change.
• 12m%Change → annual change.
• AveragePriceSA → seasonally adjusted average price.
• SalesVolume → number of sales (lagged, back-filled later).
• Most of the rest are indices, used for statistical comparison, less digestible but be useful depending on need.

Most useful in practice

For dashboards/analysis, you’ll likely use:

• AveragePrice, 1m%Change, 12m%Change (headline)
• Property-type splits (DetachedPrice, SemiDetachedPrice, etc.) for structural insights
• Funding split (CashPrice, MortgagePrice) to show how cash vs mortgage differ
• Buyer type (FTB vs FOO) for affordability trends
• New vs Old property splits
• SalesVolume (with caveat: lags by a few months, often blank for the current month)

Notes:

FTB - First Time Buyer
FOO - Former Owner Occupier (Just means someone who owned a house is moving or buying another)
New - Brand new house
Old - Every other property that is not brand new