All work undertaken by JJA Windows & Doors is covered by Assure Certification. This gives you peace of mind and you can be rest assured that your windows and doors have been installed to comply with Building Regulations. Assure is an official, UKAS-accredited Competent Persons Scheme authorised by the Ministry of Housing, Communities and Local Government (MHCLG) for the replacement of windows, roof windows, roof lights and doors in England and Wales