We recently bought two-thirds of an acre of building land sited outside the development policy boundary. There was an original building on the site which had been demolished and foundations for a new property laid. When we bought the land it had been substantially enlarged and we applied for permission for a new building on another part of the plot. Planning permission was duly granted but the local council omitted to revoke the previous planning permission. It has subsequently agreed that there are two valid planning permissions on the plot and immediately agreed the landscaping scheme we had submitted with our planning application. The council has told us that both permissions cannot be implemented together but we have overlaid both the original layout plan and our latest plan and there is only one area of conflict. The area around the existing foundations tends to be wet and we had proposed planting a tree in that location. The council has suggested we apply for something called a certificate of lawful use (CLU) but as far as we can tell, neither type of CLU is relevant to this situation. None of the case law (Pilkington v Secretary of State and its derivatives) seems to apply due to the differences in timeline and while it was an understandable action, we are not sure the council acted properly when agreeing the proposed landscaping. Obviously we would prefer not to pay out yet another application fee, nor to waste any more time and we would like to have an additional building plot available to us. How should we proceed?