Paulie_d

I want to replace the timber sashes in two windows in my flat as they are rotten and beyond economic repair. As the property is listed (Grade 2), I have applied for listed building consent to replace them with like for like replacements i.e. single glazed timber sashes. After nearly five months, the planning department has indicated that my application will be approved. However they have also stated that I cannot replace the windows unless I apply for full planning consent. Despite making several requests over the last month, they haven't responded to my questions regarding why this is required. Can anyone help? I have replaced other windows in the flat and in each case, listed building consent was all I needed. I am not sure what additional information over and above what was supplied for the listed building consent is required. I have attached a photo of the windows.