I have a 12 way split load consumer unit (six way on either side). Now at the moment I have the rings for downstairs and the kitchen on the RCD protected side and four spares, and on the non RCD side the two lighting circuits, cooker, immersion, upstairs ring etc etc and no spares. My question is which circuits would be better on RCD side and which on the non RCD side as a 6 and 6 split seems an excessive waste of RCD protected MCB's?