On 21 February 2013 a new series (2010 = 100) was published with reference year 2010. The weights used for this series are based on the value of the total housing stock. In the previous series (2005 = 100) the weights were based on the relative share of dwelling transactions in a recent year. Starting from January 2014, the weights of the index will be refined further to fulfil the purpose of the index better. These new weights will be based on the total owner-occupied housing stock. Where possible, a retrospective revision will be carried out. Analyses have shown that the effect of this revision on the index values and changes therein will be very small.