22 April 2026
As part of the work to move the production of the UK House Price Index from a legacy platform to a new production system an error has been identified in the calculation of fixed basket weights for the first-time buyer and former owner occupier supplementary series.
The error was caused by the way cash sales are allocated the appropriate buyer status in the legacy system, which has been corrected in the move to the new system, and thus for the new 2026 weights.
This error does not affect any of the headline UK HPI estimates and is isolated to the supplementary first-time buyer and former owner occupier series only. At this stage, we will not be correcting these series. We are carrying out a wider review of the methodology used in the production of the UK HPI during 2026, and subject to the recommendations, we will update the series to incorporate the corrected weightings and any subsequent methods improvements. Therefore, we advise caution when comparing breakdowns for first time buyers and former owner occupiers before and after the January 2026 estimates.
