House Price Index

House price indices are published by government statistical agencies, mortgage lenders, property portals and research firms. They help households, investors, lenders and policymakers understand trends in the housing market.

Different indices use different methods and data. Some use completed sales recorded by land registries, others use mortgage approvals or asking prices. Many use techniques to adjust for differences between properties sold in different periods, such as comparing repeat sales of the same homes or controlling for size, type and location.

Examples include the UK House Price Index, published by HM Land Registry and the Office for National Statistics, the S&P CoreLogic Case-Shiller indices in the United States and indices from lenders such as Nationwide and Halifax in the UK.

For example, if a house price index rises from 100 to 106 over a year, average prices have risen about 6%.

House price indices often differ in the short term because of their methods and timing. Central banks watch them closely, since housing affects household wealth, borrowing and spending.