House Price Index YoY

The UK House Price Index YoY measures annual change in the mix-adjusted average price of homes across the United Kingdom. It is jointly produced from administrative records by HM Land Registry, ONS, Registers of Scotland and LPSNI. It holds National Statistic status for independent quality assurance. It is not a survey, since it rests on registrations and tax data rather than a panel of respondents. It covers completed sales at full market value, whether paid in cash or with a mortgage. Gifts, discounted transfers and commercial deals sit outside its scope. YoY compares a period with the same period 12 months earlier, so it tracks the value of a typical property over a full year.

The reference period is the period in which sales complete. Registrations arrive between 2 weeks and 2 months after completion, so the first estimate rests on about 40% of eventual transactions. Publication follows about 2 months after the reference period, at 9:30, with Northern Ireland refreshed on a quarterly cycle. The timetable can shift around holidays. Each release carries the national headline plus country, regional and local detail, with seasonally adjusted series above regional level. Figures covering 12 months revise as more registrations arrive. The second estimate rests on about 80% of transactions and the third on about 85%. First estimates tend to revise downward, so a single release carries little weight.

The headline follows the mix-adjusted average, not the price of any single home. Published splits show where strength or softness concentrates.

• Property type: detached, semi-detached, terraced and flat-maisonette averages move on their own mix and demand.
• New-build vs existing, about 9%: new homes carry a small headline weight. The nearest 2 months stay unpublished for this split when new-build deals run thin.
• Funding: cash purchases against mortgage purchases across Great Britain.
• Buyer: first-time buyers against former owner-occupiers across Great Britain, with cash buyers grouped as former occupiers.
• Geography: national, country, regional, county, local authority and London borough detail, with a 3-month average below regional level and the Isles of Scilly excluded.
• Repossessions: counts of repossessed-home sales by region, shown as volumes rather than price moves.

1. Match: each price-paid sale is joined to attribute records on place, Acorn area type, type, size, rooms and age. Every deal then carries price plus traits.
2. Hedonic model: log price is estimated from six traits, since prices skew log-normally, and traits explain about 0.8 of price variation. The Northern Ireland model omits rooms on weak data.
3. Geometric mean: predicted prices are averaged geometrically, and the ratio of successive means gives the move. For illustration, means of 252000 then 257000 lift the index to about 102.0, a monthly rise of about 2.0%.
4. First estimate: the previous full-model price is grown by the reduced-model move, which drops the age trait. For illustration, a full-model 260000 with reduced-model 258000 then 265000 gives about 267054.
5. Weights, base and smoothing: mix weights refresh from completed-year deals, the level anchors to a base of 100, and small areas use a 3-month mean. Northern Ireland quarterly values carry into the next 2 months, then revise.
6. Annual and monthly change: monthly change compares adjacent periods while YoY compares the period with the same period 12 months earlier. The headline is nominal and non-seasonally adjusted. For illustration, an index of 105.1 against 100.0 a year earlier means about 5.1% YoY.