Basically were starting a double storey extension on wed and last ngiht dh had this bright idea to move the utility and toilet into the new downstairs long sun room we will gain on the ground floor with a view to later knocking kitchen through to utility to make a big kitchen but thus still having a utility room and down stairs loo (so we can still hide my ironinig mountain). It easy enough to do i think as moving it back to the next room out so it remains at back of house and knocking up a partition wall in my now not so long sun room thingy. It wont affect outside look of the new extension but to ammend plans when already got permission do we still need to inform and seek council planning permission or as internal can we just crack on do you think? With it being building week so to speak.... (yes i could royally crack dh for this as now i have a doubt in my head where previously there was not one). He is basically on abotu it now as builder if comes back to do this in the future as we planned in a few years when we have enough cash for a complete new kitchen he is worried he will have to dig out floor etc.. to fit loo waste fittings etc to drains or as going to an external wall anyway would it not matter. Any useful advice from someoen who has ammended ideas after sought planning permission would be great