Guidance

About the UK House Price Index

Updated 13 December 2016

1. Introduction

The UK House Price Index (UK HPI) captures changes in the value of residential properties.

The UK HPI uses sales data collected on residential housing transactions, whether for cash or with a mortgage. Properties have been included:

  • in England and Wales since January 1995
  • in Scotland since January 2004
  • in Northern Ireland since January 2005

Data is available at a national and regional level, as well as counties, local authorities and London boroughs.

1.1 Experimental statistics

The new UK HPI has been published initially as an experimental official statistic to allow for users to acclimatise to the format of the new HPI, to evaluate user reaction to the new data, evolve the publication of data further to meet user requirements and to further develop the data sources used in the production. Whilst the methodology for the new UK HPI has been finalised, further work is taking place to secure additional property attributes data (such as from Scottish Assessors) that will supplement and provide additional assurance to the production process going forward.

It is expected that we will seek to take the necessary steps to remove the experimental status at the end of 2016, once the above points have been implemented and then progress with the assessment of the new UK HPI as a National Statistic.

Please note that the Northern Ireland Residential Property Price Index, used as a component source in the production of the new UK HPI remains an official statistic (i.e. this is not classified as experimental).

2. Data sources

The main sources of price paid data used in the UK HPI are the Land Registry for England and Wales, Registers of Scotland and Her Majesty’s Revenue and Customs Stamp Duty Land Tax data for the Northern Ireland Residential property prices index (RPPI).

2.1 Land Registry for England and Wales

Information on residential property transactions for England and Wales, collected as part of the official registration process, will be provided by Land Registry for properties that are sold for full market value. The dataset contains the sale price of the property, the date when the sale was completed, full address details, the type of property (i.e. detached, semi-detached, terraced or flat), if it is a newly built property or an established residential building and a variable to indicate if the property has been purchased as a financed transaction (for example using a mortgage) or as a non-financed transaction (cash purchase).

All this information is currently published by Land Registry in its Price Paid Dataset (PPD), with the exception of the funding status indicator. This is not publicly available as this data is considered personal information and would breach data protection rules.

2.2 Data exclusions

There are a number of registrations excluded from the version of the Price Paid Data (PPD) used in the UK HPI. These are:

  • all commercial transactions
  • sales that were not for full market value
  • transfers, conveyances, assignments or leases at a premium with nominal rent which are:
    • ‘Right to buy’ sales at a discount.
    • subject to an existing mortgage
    • to effect the sale of a share in a property
    • by way of a gift
    • under a Compulsory Purchase order
    • under a court order
    • to Trustees appointed under Deed of appointment
    • Vesting Deeds Transmissions or Assents
    • of more than one property
    • leases for seven years or less

2.2 Registers of Scotland

Registers of Scotland (RoS) provides residential property sales for Scotland in the calculation of the new UK House Price Index (HPI). The Scotland data follows a similar process to the Price Paid Data (PPD) where the data provided for the HPI is a by-product of the Scottish property registration process, whereby property sales are submitted to RoS on completion of a sale. Data is gathered from these applications and entered into the RoS Land Registration System (LRS). A weekly extract of all sales data is then taken from LRS and undergoes a quality assurance process to check the price paid, date of entry, property type (land, commercial, residential, forestry, agricultural and other) and to identify market value residential sales (as opposed to non-market sales similar to those detailed for PPD). This data is then combined with further details, such as full address and house type (detached, semi-detached, terrace or flat), using the RoS Geographical Information System database to provide a comprehensive source of data that can be provided each month for use in the new HPI.

In addition, a funding status indicator and a new build indicator are also added to the final dataset. The funding status indicator is identified by whether the applications for registration of a market value residential sale also contain an application for registration of a standard security mortgage deed. All applications with a mortgage deed are mortgage sales, while all those without an accompanying mortgage deed are marked as being a cash sale. The new build indicator is given to every sale of an individual property from a builder’s development title. The coverage of the RoS data differs to the PPD slightly in that transactions relating to residential properties where the buyer or seller is a corporate body, company or business are included within this data house price index will continue to be calculated and published quarterly. Northern Ireland data will be provided to Office for National Statistics (ONS) quarterly, and will be combined with the Great Britain data to give overall figures for the UK. The overall UK figure will be calculated by keeping the house prices in Northern Ireland constant for each month in a quarter. In the two months following the end of a quarter, when Northern Ireland results for the most recent quarter are not yet available, indices and house prices for Northern Ireland will be carried forward from the previous quarter. They will then be revised when the quarter is complete.

2.3 Northern Ireland data

The Land & Property Services/Northern Ireland Statistics & Research Agency house price index will continue to be calculated and published quarterly. Northern Ireland data will be provided to Office for National Statistics (ONS) quarterly, and will be combined with the Great Britain data to give overall figures for the UK. The overall UK figure will be calculated by keeping the house prices in Northern Ireland constant for each month in a quarter. In the two months following the end of a quarter, when Northern Ireland results for the most recent quarter are not yet available, indices and house prices for Northern Ireland will be carried forward from the previous quarter. They will then be revised when the quarter is complete.

2.4 Council of Mortgage Lenders – Regulated Mortgage Survey

The Regulated Mortgage Survey (RMS) is the Council of Mortgage Lender’s version of the Mortgage Product Sales Data (PSD) that all regulated lenders report to the Financial Conduct Authority (FCA). This is detailed transaction level data on mortgage completions. Starting in April 2005, the RMS now contains over 12 million individual mortgage sale records.

It is collected electronically, with all reporting firms submitting according to FCA-defined data definitions, and in a standard xml format, ensuring consistent data structure. Data coverage is estimated to be around 95% of all regulated mortgages currently advanced. However, some lenders do not permit their data to be transferred to third parties, like ONS, so the share of the market covered by data received by ONS is about 70%.

Reporting fields include purchase price, completion date of property sale, type of borrower (first time buyer (FTB) or home mover) new or second hand property, type and size of dwelling. The RMS is the only comprehensive source of data available for the type of borrower and provides the necessary data to allow the new HPI to be produced according to whether the buyer is a first time buyer or an existing owner. The RMS is also a key source of data used in the production of house prices for inclusion in the Retail Price Index and will continue to be for the foreseeable future.

3. Property attributes data

There is comprehensive data available on the price of transacted property across the UK; however, this price data is limited in terms of details regarding the physical characteristics of the property.

The use of price data alone is insufficient for the calculation of an inflationary index for house prices due to the fact the composition and type of property sold can differ vastly between periods. Therefore, in line with recognised international best practice, hedonic regression and mix-adjustment is used to account for the change in composition.

For a hedonic regression model to be work sufficient, details regarding the attributes of properties sold are required to supplement the price paid data. For the production of the UK HPI, these attributes are available from a number of official sources described below.

3.1 Valuation Office Agency Council Tax Valuation list

The main source of property attributes data that will be used to supplement Price Paid Data (PPD) for England and Wales is administrative data taken from the Council Tax Valuation list maintained by the Valuation Office Agency (VOA).

The VOA has been responsible for banding properties for Council Tax since the tax was first introduced in 1993; before then, the VOA was responsible for the earlier system of domestic rates. The Council Tax Valuation list is a robust source of property attributes (such as the size of the property) data that covers, in principle, all residential properties in England and Wales.

3.2 Land and Property Services Northern Ireland Valuation List

Land and Property Services maintains the list of Northern Ireland properties which are valued for rating purposes. The data are maintained and validated similarly to the VOA data described above. The Valuation List database contains all the property attributes required for the hedonic regression used in the production of the Northern Ireland Residential property prices index (NI RPPI).

3.3 Energy Performance Certificates Scotland

Scottish Energy Performance Certificates (EPC) is used to provide the floor area of the property and the number of habitable rooms required for calculation of the new HPI. This will be matched against the price paid data provided by RoS (using the address details of the property).

3.4 ACORN classification

A key determinant of house prices is the demographic characteristics of the area in which the property is located, such as the affluence of those people living in the area. A well-established geo-demographic segmentation of the UK is available through the ACORN dataset, produced and licensed by CACI Ltd. ACORN segments postcodes into categories and groups by analysing significant social factors and behaviours.

4. Calculating the UK HPI

The calculation of the UK HPI is performed by the Office for National Statistics. Further information on the methodology applied is available via the published article ‘Development of a single official House Price Index’.

4.1 Methodology

The UK HPI applies a hedonic regression model that utilises the various sources of data on property price (for example the Price Paid dataset) and attributes to produce up-to-date estimates of the change in house prices each period.

More details of the UK HPI methodology on the ONS website.

4.2 Geometric mean explained

There are different ways of calculating average prices. These include the arithmetic mean (simple mean), the geometric mean and the median.

The arithmetic mean is greatly influenced by the few high value properties and will therefore not give a true reflection of the average price of a standardised property.

The geometric mean reduces the weighting given to high value properties when compared to the arithmetic mean and is typically lower, usually closer to that of the median.

For the UK HPI, the standard average house price is calculated by taking the average (geometric mean) price in January 2015 and then recalculating it in accordance with the index change back in time and forward to the present day.

A 3 month moving average has been applied to estimates below the regional level. For example, at the local authority level, the published estimate for March is a simple average of the calculated estimates for January, February and March. This helps remove some of the volatility in the series at this level. Volatility still remains in estimates for local authorities with fewer transactions, such as Shetland, Orkney and the Western Isles. Northern Ireland estimates are unaffected by this as they are only available on a quarterly basis.

4.3 Monthly and annual price changes

The ‘annual’ percentage change in house prices is simply the price change relative to the same month twelve months earlier. For example, if the HPI release is for February, then the ‘annual’ price change reports the percentage change in values relative to February in the previous year.

This annual rate of price change reflects the best estimate for how much the value of a typical property has changed over the preceding twelve months. Similar to the ‘annual’ change, the ‘monthly’ percentage change estimates the percentage change in average house prices relative to the previous month.

4.4 Monthly UK HPI revision

There is a time-lag of between 2 weeks and 2 months between the sale of a property and the subsequent registration of this information on the Register. As a result, UK HPI data for the two most recent months will be subject to revision.

4.5 Seasonal adjustments

Seasonally adjusted series are calculated at the regional and national level only. These data can be found within the data tables.

4.6 Inflation

The UK HPI measures nominal house price changes and is not adjusted for inflation. Users of the UK HPI can make their own inflation assumptions and adjust the UK HPI accordingly.

4.7 Small local authority districts not shown on the UK HPI

Due to the small volume of sales for these areas, the UK HPI would not always provide a reliable measure of price movement. This may become possible as the amount of data increases.

4.8 Recent volumes not reported

There are partial sales volume data for the months immediately preceding the UK HPI release. However this is not published because the data is not complete. We aim to report on accurate and reliable information and therefore do not want to release sales volume data that has the potential to be misleading if quoted out of context.

5. Repossessions

Details of repossession sales are only available for England and Wales.

In August 2016, we will begin reporting on Repossession data for England and Wales.

For England this will be volumes of repossessions recorded by Government Office Region. The data will be shown as a table and in a heat map. The data will also be available to download as a .csv file.

For Wales there will be a headline figure for the number of repossessions recorded in Wales. This data will be included in the .csv file.

6. The difference between the UK HPI and others

Currently, there are a number of different sources of house price statistics published in addition to the UK HPI. There will be differences in the data published by each source, as there are differences in both the data and methodology used. For example, Rightmove use asking prices, sources such as Nationwide and Halifax use their own mortgage approvals data, while the UK HPI uses data at the end of the conveyancing process, calculated based on completed sales. Therefore, the UK HPI is not directly comparable with these other indicators.

Halifax house price index and Nationwide house price index

Both Halifax and Nationwide produce house price indices based on their own mortgage approvals only and therefore will not include any cash transactions. They both have UK-wide coverage, and since the Halifax and Nationwide use only their own in-house data they can process them immediately and do not have to await the receipt of data from other lenders. This means that they are timelier than the UK HPI.

LSL Acadata house price index

The LSL Acadata (previously the LSL Property Services/Acadametrics) HPI reflects all transactions, as opposed to data samples, and provides mix and seasonally adjusted results at national, regional and county or unitary district or London borough levels.

The index can be accessed at Acadata.

Rightmove house price index

The Rightmove index includes all property types that are advertised on its website. However it includes houses that do not subsequently sell and reports only asking prices. If house price movements are different between the non-selling and selling

houses then this will affect the accuracy of estimates of house prices and changes in them.

Registers of Scotland official quarterly housing market statistics

Registers of Scotland will continue to produce average house prices based on arithmetic means of these transactions, which is published as the quarterly housing market statistics in the second month after the month to which the figures refer to.

7. Republishing data

UK HPI data is published under Open Government Licence. When using or publishing data from the UK HPI reports, background tables or search tool, you will need to add the following attribution statement:

UK HPI data published by Land Registry © Crown copyright 2016.

When you publish the data, be sure to include information about the nature of the data and any relevant dates for the period of time covered.

Neither Land Registry nor any third party shall be liable for any loss or damage, direct, indirect or consequential, arising from:

  • any inaccuracy or incompleteness of the data in the UK HPI
  • any decision made or action taken in reliance upon the data

Neither shall Land Registry or any third party be liable for loss of business resources, lost profits or any punitive indirect, consequential, special or similar damages whatsoever, whether in contract or tort or otherwise, even if advised of the possibility of such damages being incurred.

8. Data tables

When the UK HPI data tables are published each month, they represent our best available view on historic house price movements at the time. As new information becomes available, the tables are revised to reflect any new data. Each month the new data will be added and the previous 2 months updated to reflect any addition sales added for those months.

As the NI House Price Index is published quarterly and sales data form the basis of future domestic revaluations, the NI price data series will be revised as and when necessary to take account of any new sales information received, therefore the most recently published data series from Jan 2005 should be used NI House Price Index from Q1 2005.

8.1 How this data is different to data available from the ‘Search the House Price Index’ tool

The Search the UK House Price Index tool allows customers to produce printable reports derived from the House Price Index data. The reports can also be downloaded in CSV or Turtle formats, and the SPARQL query generated in the background viewed. Real-time preview allow search options covering average prices, indices, sales volumes and property types ranging from January 1995 to the most recent available data to be changed easily.

The House Price Index data tables are for customers that would like to download the full dataset in a more usable format which incorporates data behind the UK House Price Index. The tables are made up of:

  • UK HPI data tables
  • average price
  • sales volumes
  • cash mortgage sales
  • First time buyer and former owner occupier
  • New build and existing resold property
  • index (Seasonally Adjusted)
  • average price (Seasonally Adjusted)
  • repossession (from August 2016)

If you would like to understand more about the data tables and the differences between the figures, please read the following technical information.

8.2 Format of data

The data is available in CSV and linked data formats.

8.3 How to access the data

UK HPI data is published monthly in CSV and linked data formats on data.gov.

8.4 Seasonal adjustment

The difference between the tables called Index and Index (Seasonally Adjusted):

  • the Index table contains monthly residential property price index at regional, county/unitary authority and London borough level.
  • the Index (SA) table contains seasonally adjusted monthly residential property price indices at regional and national level.

8.5 Monthly change and annual change

Data presented in the Monthly Change and Annual Change tables:

  • the Monthly Change table contains monthly change figures which represent the month-to-month percentage change of the index.
  • the Annual Change table contains annual change figures. These represent the percentage change in the index over the last 12 months.

8.6 Sales volumes table

This table contains counts of all sales included in the electronic register at the time of data extraction. The data collection delay mainly affects the most recent months. The two most recent months are therefore omitted from this data to avoid reporting misleading volumes.

8.7 Levels at which the data is presented

The data presentation is in:

  • ‘Monthly Change’
  • ‘Index’
  • ‘Annual Change’
  • ‘Average Prices’
  • ‘Sales Volumes’ are provided at national, regional, county/unitary authority, local authority and London borough level

Data in ’Average Prices (SA)’ and ‘Index (SA)’ tables are presented at national and regional level.

9. Searching the UK House Price Index

9.1 About the search tool

The UK HPI search tool allows you to customise searches of the House Price data, using specific areas, dates, house types and indicators.

9.2 Browser support

As of April 2014, Land Registry no longer tests new application software releases against Microsoft Windows before Windows 7.

Microsoft Internet Explorer 11, Microsoft Edge, Safari 8 onwards and the latest version of any browsers which automatically update, such as Mozilla Firefox and Google Chrome are supported.

9.3 Data items displayed

The UK House Price Index (UK HPI) is published by Land Registry using sales data collected on residential housing transactions, whether for cash or with a mortgage,

Data item Description
House Price Indices Captures changes in the value of residential properties from a base of 100 set in January 2015
Monthly Change The month-to-month percentage change of the index.
Yearly Change The change in the index over the last 12 months.
Volume of Sales The volume of sales on which the analysis is based. Figures include all sales captured in our Price Paid Dataset at the point of extraction. Sales in the most recent month may not reflect the actual number of sales due to the registration lag time these are revised in months 2 and 3.
Average Price Standardised average prices. These can be pulled for all properties or can be split into property type.

9.4 How to view your results

Our UK HPI data is presented at national, regional, county and at borough or metropolitan district level. When you start typing in the name of an area a drop down list of available options will appear. You need to select the option from that drop down to start the search.

If you are unsure of the areas available for reporting on, use the map icon to view the different areas available.

9.5 Viewing results

The search tool initially presents results for the UK for the previous 12 months showing the Index, average price, volumes, percentage monthly and annual change in both tabular and graphic form. You can change the options (Date, Location, indicators and property types)

9.6 Available data

Not all data is available for all countries. For Scotland and Northern Ireland data is not available at regional or county level.

9.7 Differences between the Search the UK House Price Index tool and the data tables

The Search the UK House Price Index tool allows customers to produce printable reports derived from the House Price Index data. The reports can also be downloaded in CSV or Turtle formats, and the SPARQL query generated in the background viewed. Real-time preview allows search options covering average prices, indices, sales volumes and property types ranging from January 1995 to the most recent available data to be changed easily.

9.8 The significance of the Beta status

The beta status allows us to review the service and make changes to the current format. We will collate feedback during the BETA period and where appropriate make changes to the search tool.

10. Calendar release dates

Publication dates for the next 11 months UK House Price Index (HPI).

Month and year of the data Publication time and date
August 2016 9:30am, 18 October 2016
September 2016 9:30am, 15 November 2016
October 2016 9:30am, 13 December 2016
November 2016 9:30am, 17 January 2017
December 2016 9:30am, 14 February 2017
January 2017 9:30am, 21 March 2017
February 2017 9:30am, 11 April 2017
March 2017 9:30am, 16 May 2017
April 2017 9:30am, 13 June 2017
May 2017 9:30am, 18 July 2017
June 2017 August 2017*
*to be confirmed  

11. Pre-release access

The UK HPI information is sent to the following people 24 hours before general release:

Job role Department
Statisticians in Communities Analysis Division Scottish Government
Economists inCommunities Analysis Division Scottish Government
Cabinet Secretary for Finance and the Constitution Scottish Government
Keeper Registers of Scotland
RoS Communications Registers of Scotland
Commercial Services Director Registers of Scotland
Head of Products Registers of Scotland
Prime Minister 10 Downing Street
Private Secretary 10 Downing Street
Principal Private Secretary 10 Downing Street
Head of Research and Information 10 Downing Street
Briefing Official 10 Downing Street
Special Advisor 10 Downing Street
Deputy Chief of Staff 10 Downing Street
Chief of Staff (joint) 10 Downing Street
Chief of staff (joint) 10 Downing Street
Principal Private Secretary 10 Downing Street
Private Secretary 10 Downing Street
Special Adviser 10 Downing Street
Statistician - Housing and Planning Statistics Department for Communities & Local Government
Minister of State for Housing and Planning Department for Communities & Local Government
Press Officer Department for Communities & Local Government
Special Adviser Department for Communities & Local Government
Special Adviser Department for Communities & Local Government
Chancellor of the Exchequer HM Treasury
Chief Secretary to the Treasury HM Treasury
Commercial Secretary to the Treasury HM Treasury
Permanent Secretary HM Treasury
Exchequer Secretary to the Treasury HM Treasury
Economic Secretary HM Treasury
Financial Secretary HM Treasury
Chief Economic Advisor HM Treasury
Duty Press Officer HM Treasury
Duty Press Officer (CHX Spokesperson) HM Treasury
Special Adviser HM Treasury
Special Adviser HM Treasury
HMT Briefing Preparing Official HM Treasury
HMT Briefing Clearing Preparing Official HM Treasury
Housing Statistics Analyst Welsh Government
Housing Statistician Welsh Government
Minister Department of Finance (DoF)
Special Advisor Department of Finance (DoF)
Chief Executive Land & Property Services
Senior Press Officer, DoF Communications Office Department of Finance (DoF)
Information Officer, DoF Communications Office Department of Finance (DoF)
Executive Officer I, DoF Communications Office Department of Finance (DoF)
Chief Executive and Chief Land Registrar Land Registry
Private Secretary to the Chief Executive Land Registry
Director of Digital Services Land Registry
Director of Legal Services Land Registry
Director of Operations Land Registry
Head of the Chief Land Registrar’s Office Land Registry
Head of Corporate Communications & Engagement Land Registry
Head of HR Service Land Registry
Head of IS Service Delivery Land Registry
Public Affairs Manager Land Registry
Public Affairs Officer Land Registry
Press and PR Manager Land Registry

12. Contact

Lorna Jordan, Product Manager, Land Registry

Rhys Lewis, Head of Housing Market Indices, Office for National Statistics

Ciara Cunningham, Statistician for the Northern Ireland HPI