"The Land Registry House price index is considered the most reliable estimate of regional house price series for the UK. However, it is published with a lag. Forecasting more timely house prices therefore requires a judgement call deciding which of the other house price series the forecaster should use. This paper applies a number of filtering techniques to Land Registry the Halifax, the ODPM, the Nationwide and RICS estimates of regional house prices to construct the ""ideal"" house price index for each region of the UK. We find that whilst a composite of indices provides a more accurate measure of house prices this varies over time. "