We bought a house that has the garage converted to an office. Access is from a door off of the lounge. We understand this was done about 14 years ago but without any permissions. The walls have been plastered and the floor built up and covered with laminate. There is lighting and heating and double glazed doors at either end. There are no signs of damp or any other defects. Should I apply for retrospective permissions and if so will I need to take the floor up etc., or should I just leave well enough alone?