Housing index number inflates

Homebuyers, sellers and Bank of England interest rate setters trying to gauge where the property market is going are about to be bombarded with yet more information. A new monthly house price index claiming to offer the most up to date picture on property values goes live tomorrow, and will include data on homes put up for sale as recently as last Friday.

The index is being published by Rightmove, which describes itself as Britain's biggest property website. Rightmove covers 30% of all estate agents and says its report is based on the largest sample of data of any survey apart from the land registry's. At any time it displays a stock of about 140,000 properties.

The first survey is published tomorrow and, like those produced by Halifax and Nationwide building society, will include the UK average price, the monthly and annual increase or decrease, plus regional data.

However, while the two lenders take their data from approved mortgage applications, Rightmove's index is based on asking prices of properties marketed by its 2,900 member estate agents.

A spokesman indicated that this week's figures were likely to show a housing market that has cooled but is still growing.

Rightmove claims that its rivals' figures are about seven weeks behind its own data, adding that Halifax and Nationwide's latest figures relate to houses that probably first came on to the market in May.

"It will act as an indicator of where the housing market is going rather than a historic 'snapshot' of what has happened in the past," said the spokesman of the new index.

This apparent pot-shot at Halifax is surprising in that the high street bank is one of Rightmove's backers - the website is a joint venture between the estate agency businesses of Halifax parent group HBOS, Countrywide Assured, Royal & Sun Alliance and Connells.

Rightmove dismissed any suggestion that the two indices could end up bitter rivals, and Halifax was also keen to stress it was not fazed by this new challenger from its own stable.