Bright light

Looking to replace four windows at the side of my flat. Two will be like for like replacements and two (situated in the kitchen) will need to lose a few centimetres of depth I.e. raising the sill line to allow for kitchen worktops to sit comfortably beneath the bottom of the window. I own share of the freehold and have other freeholders permission but as it is a flat and hence requires planning under Lewisham council guidelines for replacing any windows. Two of the windows are UPVC/Aluminium and two wood. Intend to replace windows in double glazed wood with 3 being sash windows in keeping with conservation area. As all windows are not in direct street views, I don’t expect any planning objections but obviously some simple professional drawings/sketches and photos will hopefully smooth a quick planning approval if drafted and formatted by a professional familiar with the jargon needed to satisfy Lewisham council….