This guidance highlights the differences between the Scotland figures within the UK House Price Index (HPI) and our house price statistics.
For more information about how we compile our statistics, see our guidance notes.
A guidance document comparing different house price indices in the UK is available.
Summary
The table below provides an overview of the differences between the methodology and content of the HPI and RoS unadjusted statistics.
| House Price Index | RoS House Price Statistics | RoS Small Area Statistics | |
|---|---|---|---|
| Links | HPI | House Price Statistics | Open Data |
| Frequency of publication | Monthly | Monthly/ quarterly/ calendar year/ financial year | Calendar year |
| Base data source | House Price Index: Applications for registration of residential sales in the land register, plus house types derived using RoS methodology and base mapping data (Ordnance Survey ©Addressmap) | ||
| Date range of extraction | Based on the date of entry to the property | Based on the date the application is received for registration on the land register | Based on the date the application is received for registration on the land register |
| Price Range | All market value sales | Medians: All market value sales Means: restricted to sales between £20k-£1m | Medians: All market value sales Means: restricted to sales between £20k-£1m |
| Calculation of average price | Geometric mean | Medians and Arithmetic means | Medians and Arithmetic means |
| Methodology | Hedonic regression model to adjust for case mix | unadjusted | unadjusted |
| Seasonal adjustment | Yes | No | No |
| Revisions | 13-month cycle | Whole series revised monthly, quarterly, and annual as appropriate | Whole series revised annually |
| Results | House Price Index | RoS House Price Statistics | RoS Small Area Statistics |
| Volume of sales | Yes | Yes | Yes |
| House types | Yes | Yes | No |
| Cash sales | Yes | Calendar and financial year | No |
| New builds | Calendar and financial year | No | |
| First time buyers identified | Yes | No | No |
| Quartiles | No | Yes – quarterly and annually | Yes |
| Deciles | No | Financial year | No |
| Geographies | UK, Scotland, and LA | Scotland and LA monthly; urban and rural annually | Scotland, LA, Scottish Parliamentary Constituency, Health Boards, Electoral wards, Data zones and Intermediate zones |
Average prices
The average price trends when comparing the HPI with RoS house price statistics are very similar. RoS data is based on the date of registration, while the HPI is based on the date of entry. Registration can occur up to several weeks after the date of entry. In 2022 the date of registration was on average 19 days after the date of entry.
Typically, the arithmetic mean will lead to a higher average price than other measures. Due to the distribution of residential property prices, the arithmetic mean can be influenced by the sale of a few high value properties. The geometric mean will typically be closer to the median than the arithmetic mean.
The HPI monthly figures are smoother than the RoS monthly house price statistics, again because of the different methodologies used. The HPI figures are mix adjusted, while the RoS house price statistics are unadjusted, which means the RoS figures are more prone to fluctuations in the market, for example if a high number of high or low-value sales are registered within a particular month.
Volumes
There are slight differences in the volumes being presented because the RoS data is based on date of registration, while the HPI is based on date of entry. RoS volumes, when used for arithmetic means, excludes any sales below £20,000 and above £1,000,000. The HPI methodology does not apply price limits but excludes outliers. When medians are used all market value sales are included.