Data Cleansing

Using last year's Council tax Base Form and the NHB data arising, English Councils brought 15,725 empty home back into use (over 5% of these were in humble Brum). The attached table shows how many empty homes were returned to use since 2004 if if one were to use the NHB- Council tax base Form method of calculation. What will be the change in nos of empety homes in October this year, just 6 months after the NHB was launched? What are the best ways of cleansing our Council Tax data in a cost effective and meaningful way?