Data Sources & Methodology
Full transparency on every data source used by ValuInsight AI, what we use, why, and what its limitations are.
Our Data Integrity Principle
ValuInsight AI prioritises verified, official UK government and public register data as the foundation of all valuations. AI-generated content is used only as supplementary intelligence and is always clearly labelled. We believe in full transparency about data provenance so users can make informed decisions about how much weight to place on any output.
HM Land Registry, Price Paid Data
Description
Records of all residential property sales in England and Wales registered with HM Land Registry. Includes sale price, property type, tenure, and address.
How We Use It
Used as the primary price anchor for our valuation models and comparable sales analysis.
Refresh: Monthly releases, current to ~6 weeks
Known Limitations
Does not include new builds sold off-plan, right-to-buy purchases, or repossessions in all cases.
Energy Performance Certificate (EPC) Register
Description
Government register of EPC certificates for properties in England and Wales. Includes floor area, energy rating, property construction details, and heating type.
How We Use It
Floor area, EPC rating, and construction data used to enrich property profiles and valuation features.
Refresh: Updated as new certificates are issued
Known Limitations
Only covers properties that have had an EPC assessment. Older or unlet properties may lack certificates.
Office for National Statistics (ONS)
Description
UK House Price Index (HPI), local area unemployment statistics, inflation indices, and census data.
How We Use It
Shown alongside valuations as market context. The published out of time test found macroeconomic variables, including Bank Rate, added no measurable accuracy over a one quarter horizon.
Refresh: Monthly (HPI), quarterly (economic statistics)
Known Limitations
Area-level data; does not capture hyper-local micro-market variations.
AI Language Models (LLM)
Description
Large language models are used only to write plain English summaries of results. They do not set valuations or select comparable sales.
How We Use It
Rewording model output and explaining, in everyday language, the factors already identified by the valuation model.
Refresh: At the time a summary is requested
Known Limitations
Generated text can still read more confidently than the underlying evidence justifies. The figures themselves come from the model and from Land Registry records, not from the language model.
Bank of England, Base Rate Data
Description
Official UK Bank Rate published by the Bank of England's Monetary Policy Committee.
How We Use It
Used in mortgage and affordability calculations, and reported as market context. Adding Bank Rate to the valuation model in the published test changed the mean error by £40, within the margin of sampling error.
Refresh: Updated after each MPC meeting (~8x per year)
Known Limitations
Individual mortgage rates vary by lender and product; the base rate is a reference, not a quoted rate.
Data Disclaimer
All data is used in good faith from publicly available sources. ValuInsight AI does not warrant the completeness, accuracy, or fitness for purpose of any third-party data. Property valuations are indicative estimates based on available information and should not be used as the sole basis for financial decisions. For a formal valuation, instruct a RICS registered valuer.
Contains HM Land Registry data © Crown copyright and database right 2025. This data is licensed under the Open Government Licence v3.0.