Compliance
Regulatory framework, standards alignment, data governance, and legal disclosures.
Gadsden Valuations is a PRA SS1/23-aligned automated valuation model with published accuracy metrics and walk-forward validation against real Land Registry sale prices. It is not a RICS Red Book valuation and is not produced by a RICS-regulated firm. Where a formal valuation is required by regulation or contract, this service should not be used as a substitute.
RICS Red Book references
While this service does not produce Red Book valuations, the model and reporting are designed with reference to the relevant RICS standards governing statistical and automated valuation approaches.
PS 1.3 — Statistical valuation
RICS Professional Standard 1.3 recognises statistical valuation methods as a legitimate approach to estimating market value. It requires that statistical models disclose their methodology, accuracy, data sources, and limitations. Our valuation reports and this methodology documentation are designed to meet these disclosure requirements.
PS 1.6 — Automated valuation models
PS 1.6 addresses the use of AVMs specifically. It requires that AVM providers publish accuracy metrics, disclose confidence levels, identify the model type, and maintain an audit trail. Our confidence tier system, published backtest metrics, model version tracking, and per-valuation audit records are designed in alignment with these requirements.
IVS 105 — Valuation Approaches and Methods
The International Valuation Standards (IVS) 105 sets out the three recognised valuation approaches: market, income, and cost. Statistical models fall within the market approach when they are calibrated to actual transaction evidence. Our model is trained exclusively on realised sale prices from HM Land Registry, placing it firmly within the market approach as defined by IVS 105.
EAA ESSVM alignment
The European AVM Alliance (EAA) publishes the European Standards for Statistical Valuation Methods (ESSVM), which provide a framework for AVM quality, governance, and transparency. Our approach aligns with the ESSVM requirements in the following areas:
- • Model governance: Documented model development, versioning, and change management.
- • Performance monitoring: Published accuracy metrics with regular backtesting against new sale data.
- • Confidence scoring: Three-tier confidence classification with clear definitions.
- • Coverage reporting: Clear disclosure of geographic and property-type coverage.
PRA SS1/23
The Prudential Regulation Authority's Supervisory Statement SS1/23 sets expectations for how regulated firms should use model-driven valuations in lending decisions. While Gadsden Valuations is not a PRA-regulated firm, our model and reporting are designed to support lenders' compliance with SS1/23 requirements, including:
- • Model transparency: Published methodology, training data, and feature descriptions.
- • Accuracy monitoring: Regular, published backtest results against realised sale prices.
- • Confidence indicators: Per-valuation confidence tier enabling risk-based decision-making.
- • Audit trail: Each valuation is recorded with model version, input data, and timestamp.
Data provenance
All input data is sourced from government and public-sector bodies under their respective open data licences. We do not use scraped portal data, asking prices, or self-reported property details.
| Source | Provider | Licence | Update frequency |
|---|---|---|---|
| Price Paid Data | HM Land Registry | OGL v3.0 | Monthly |
| EPC Register | MHCLG | OGL v3.0 | Monthly |
| House Price Index | ONS / Land Registry | OGL v3.0 | Monthly |
| School data | DfE / Ofsted | OGL v3.0 | Termly |
| Crime statistics | Police.uk / Home Office | OGL v3.0 | Monthly |
| Flood risk | Environment Agency | OGL v3.0 | Quarterly |
GDPR and privacy
We take data protection seriously. Our processing activities are conducted in accordance with the UK General Data Protection Regulation (UK GDPR) and the Data Protection Act 2018.
Personal data we process
Account registration details (name, email). Valuation requests (property addresses). Payment details are processed by Stripe and never stored on our servers.
Lawful basis
Contract performance (providing the valuation service you requested) and legitimate interests (improving model accuracy, fraud prevention).
Data retention
Valuation records are retained for audit purposes. Account data is retained while your account is active and for 6 years thereafter (HMRC requirement). You may request deletion of your account at any time.
Your rights
You have the right to access, rectify, erase, restrict processing, and port your personal data. Contact us at [email protected].
Disclaimer
Gadsden Valuations is an automated valuation model (AVM) that estimates UK residential property market value using a machine learning model trained on publicly available government data. The model is validated through walk-forward backtesting against real Land Registry sale prices, with accuracy metrics published transparently on our accuracy page. Each valuation includes a confidence tier and prediction interval to support risk-based decision-making.
Gadsden Valuations estimates are not RICS Red Book valuations and are not produced by a RICS-registered valuer. They should not be used as a substitute for a formal valuation where one is required by a lender, insurer, court, tax authority, or other regulatory body, nor relied upon as the sole basis for property purchase, sale, lending, or investment decisions.
All model-based estimates carry inherent uncertainty. The confidence tier and prediction interval provided with each valuation should be considered alongside the point estimate.
Gadsden Valuations Ltd accepts no liability for losses arising from reliance on AVM estimates. Users are advised to obtain independent professional advice where appropriate.