Porthcawl Home and House Improvements – MPN Windows offering Porthcawl top rated WER Ratings for Windows A-Rated is standard with MPN suppliers installers and fitters in Bridgend CF36, Mid Glamorgan and South Wales. South Wales based Alternative uPVC Windows MPN. Suppliers and Installers of uPVC windows and doors. Specialising in PVC-U windows, patios, conservatories and doors.