Hi, I bought the mid terrace house in very poor condition over a year ago. Im in the process of replacing the ground floor external wall which are completely rotten, timber framed with earthwool itchy type thin insulation. Unsure what it was but presumably built 1970s with a gritty vinyl appearance adhered to ply. I would like to change this into a fastclad brick slips cladding and i am sure the studs are sound to hold its weight. I will add celotex insulation and breathable membrane with new osb3 boards. If i do the front first which is worst compared to the back it is 25% of the skin.Do i need planning permission or apply for building regulations? I have checked planning portals and all planning applications made in our area, none of my neighbours who replaced 1st floor upvc cladding into hung tiles applied in the council. Please advise, many thanks.