Buyers and sellers in search of a market overview in order to determine the value of a property should be circumspect when looking at some house-price statistics. It is important to remember how each index is compiled and which give a considered view because some give just a snapshot and do not always represent the full picture. According to The Times, sources of some property surveys can no longer be wholly trusted, as revealed by recent evidence. People have been warned to consider the legitimacy of the results and how the data has been compiled.

Surveys produced by lenders such as Halifax and Nationwide only capture the prices agreed on homes for which they have provided mortgages. This means that some sectors of the market - prime and super-prime in particular - may not be represented in the data-collection. Some buyers do purchase without a mortgage at all and clearly will not be included. As such, market price data can be underestimated if based on these surveys.

An index taken from the internet, such as Rightmove.co.uk or Home.co.uk, is based on the asking prices of the properties registered online. These figures therefore symbolize the seller’s desired price, and not necessarily the final sale price achieved. The statistics also do not account for properties that are on the market without being listed on the internet.

Even the Land Registry, understood to be the most accurate house-price index, has been deemed as a less than true representation of house sale prices as, despite taking into account the actual sale price on a national basis, the information can never be totally precise because there is a time-lag of several months during which the data is compiled.

Michael Fiddes of Strutt & Parker’s Mayfair office says “It is important for our client base that their profile is represented in accurate research of the property market. There is nothing like talking to someone dealing in the local market on a day to day basis to get a clear view of what is actually happening to property values in the London area .”