House sale statistics per month in the last 2 years that were included and excluded from the House Price Index

​FOI Ref: FOI/2021/2947

You asked

I read your publication that stated new house sales had been added together and included in a single month's figures.

1. Please provide me with the house sales statistics without this pooling taking place.

2. Please provide me with the number of residential sales per month in the last 2 years with the percentage of residential sales that were included in the HPI and those that were excluded from the HPI.

3. Has there been any previous pooling of new house sales onto the HPI?

We said

Thank you for your enquiry.

We have pooled new build transactions for certain months in England and Wales to account for the low transaction numbers that we have been seeing for these type of properties in particular, to ensure the data we publish is of a sufficient level of quality. Estimates have been smoothed to reduce volatility by pooling transactions for certain months, and this has been the case for every monthly release since the UK House Price Index (UKHPI) for April 2020 was published on 19 August 2020 and is accessible via the following link: UK House Price Index - Office for National Statistics (ons.gov.uk)).

In terms of transaction numbers, the sales volume data currently published on the HM Land Registry (HMLR) website is based on the un-pooled data: Sales (landregistry.gov.uk)

Transaction counts that feed into the UKHPI are available for any period up to 2 months prior to the reference month in the sales volume dataset available on the HMLR website, but because of the time it can take for a sold property to be registered with HM Land Registry, transactions for previous months will continue to feed through into the UK HPI dataset for a period after they were initially sold (12 months, in line with our revisions policy).

To help with your query, please also see the accompanying download, named 'Transactions in England, Wales and Scotland used for UKHPI in 2019 to 2021', which provides the number of transactions for England and Wales and also Scotland that were used in the production of the UKHPI for the specific reference period (i.e. at the time of publication).

The total number of monthly property transactions statistics as published by HM Revenue and Customs (HMRC) is updated monthly, and so is not directly comparable as we do not have access to the transactions statistics at the time of publication (which will have been subject to revisions each month following initial publication). However, they are available for you to refer to should you wish.

In terms of average house prices and house price growth, we do not hold analysis on this based on un-pooled data. This information would need to be created using a high level of statistical skill and judgement. Public authorities are not obligated to create information in response to FOI requests. This information is therefore not held for FOI purposes.

For context, we have not conducted this analysis due to the low number of new build transactions. It is not possible to produce the estimates without pooling to an acceptable level of quality, and as such, we have adapted our methods in response to the changes in the data to ensure we can still produce House Price Statistics to meet user needs. We review the pooling methodology each month to ensure it is still fit for purpose alongside the changing transaction counts and will continue to do so until we are able to return to our standard methodology as and when transaction counts for new builds improve over time. At this point we will update the commentary in the UK HPI statistical bulletin to reflect any changes.

If you have any further questions, please do not hesitate to contact us directly via our email address: hpi@ons.gov.uk