Which house price index is the best?

It's probably not much of a surprise that property-obsessed Britain has at least five main indices measuring house prices.

Nationwide, Halifax, the Office for National Statistics (ONS), Zoopla and Rightmove all produce data reports – eagerly awaited by home buyers and sellers every month – that detail the ups and downs of home values across the country. But their conclusions on the state of the housing market are all slightly different, which can make things a little confusing.

So, how do the property indices differ from each other? We take a look at what each one measures and which house price index is the best.

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Nationwide house price index 

The Nationwide house price index is one of the most popular indices used in the UK, with data stretching back to 1952.

The data used is the lender’s valuation at the mortgage-approval stage. This may differ from the actual sale price, but the idea is that it is near enough to the end of the home-selling process to offer a more realistic snapshot than the initial asking prices.

The index is mix-adjusted, which means it tracks a representative home by giving a relative weight to each property based on characteristics like the number of bedrooms. This prevents price disparities from arising if different types of properties are sold each month.

Nationwide releases HPI data each month, with the latest figures saying house prices were up 1.8% in the year to November. Meanwhile, prices between October and November were up 0.3%. Nationwide said the average UK house price was £272,998 in November.

The building society also said the number of mortgage approvals was similar to pre-pandemic levels as the market showed signs of resilience.

Halifax house price index 

Halifax’s house price index has data going back to 1983 and, like the Nationwide index, is based on the bank’s valuation at the mortgage-approval stage. A standardised house price is calculated using this data, and property price movements on a like-for-like basis are analysed over time.

The latest HPI figures published by Halifax reveal house prices grew by 0.7% in the year to November, down from 1.9% in the year to October. Average property price growth between October and November was flat, Halifax said. The average house price in November was £299,892, according to the lender.

The lender said it expected falling interest rates to lead to property price growth at the end of 2025 and into 2026.

Rightmove house price index

Rightmove’s house price index differs from Nationwide and Halifax in that it is based on asking prices. The asking price is usually determined at the very first stage of the home-buying process. The index also excludes inner London.

One obvious advantage of using asking prices is that it picks up price trends early on. But the asking price can differ drastically to the price at which a house is eventually sold.

One of the main issues with the Rightmove index is that it mirrors market sentiment rather than solid data, according to London estate agent Petty Son & Prestwich. There is also no guarantee that a house that's advertised will sell.

Despite this, the house price report is useful for data on discounts and how quickly properties are going under offer, which gives a good indication as to the health of the property market.

Rightmove’s latest figures suggest asking prices fell 0.6% in the year to December, while experiencing a bigger 1.8% drop between November and December. The average asking price in December was £358,138, £6,695 less than the month before, Rightmove said.

ONS/Land Registry house price index

Each month, the Office for National Statistics calculates official house price figures using sale data from HM Land Registry, Land and Property Services Northern Ireland, and Registers of Scotland. This is the most authoritative house price index.

The ONS index uses a statistical method called hedonic regression that adjusts the data to account for characteristics like the number of bedrooms.

Unlike the Halifax and Nationwide indices, which are based on mortgage approvals, the ONS data also includes cash purchases. This gives a broader view of the market.

One downside is that the index has a time lag of around two months, as it takes a little time to process conveyancers’ submissions to the Land Registry after a sale is completed.

According to the ONS, house prices rose by 2.6% in the year to September, but fell by 0.6% month-on-month. It said the average property price across the UK was £271,531 in September.

Zoopla house price index 

The Zoopla house price index uses sold prices, mortgage valuations, and data for agreed sales to calculate house prices for any given month. In other words, it tracks achieved prices, which is a key difference from an asking price index. Tracking homes that are “sold subject to contract” is a better indicator of current house prices, as the asking price often does not reflect the sale price.

The index also provides data on the number of days it takes to sell a house, giving prospective sellers an idea of how long it will take for the property to sell. This measures the time from the initial listing to going under offer.

Unfortunately, Zoopla’s index, like all other indices on this list, relies on a limited pool of data with some degree of time lag.

Latest figures, according to Zoopla, suggest house prices rose annually by 1.3% in the year to October, up £3,340 to £270,200. Between September and October, prices increased by £200 (0.07%) from £270,000.

UK Residential Market Survey by RICS

UK Residential Market Survey by RICS 

The UK Residential Market Survey by the Royal Institution of Chartered Surveyors (RICS) is very different to all other indicators in this list. It is a monthly sentiment survey of chartered surveyors operating in the residential sales and lettings markets.

It measures the percentage of surveyors reporting house price increases versus declines. While it doesn't provide an average house price for a specific month, it serves as an indicator of current and future conditions in the UK residential sales and lettings markets.

Surveyors are asked 18 questions on various metrics, such as sales, enquiries, listings, and house prices, and are required to report whether these have increased, remained the same or decreased.

A positive net balance indicates that more surveyors are observing price increases, signalling a strong housing market. Conversely, a negative net balance suggests that more surveyors are witnessing price decreases, indicating a more fragile housing market.

For instance, if 15% of surveyors reported an increase in buyer inquiries and 20% reported a decrease, the net balance would be -5%.

The latest market survey by RICS revealed a net balance of -19% of respondents saying house prices had increased over the previous three months, compared to -17% of respondents the month before.