Room in roof insulation is a unique type of insulation system that is designed specifically for properties with rooms set into the roof space. it is a very different product and involves a very different installation process.
A room in roof is typically (but not always) a bungalow which has had a loft conversion that is accessed from a fixed staircase, but it can also be an original building feature at the top of properties. Normally a room in roof will have sloping ceilings, and dormer or sloping style windows such as a veluxe or similar window at the upper floor.
A room in roof can have multiple different heat loss elements including sloped ceilings, stud walls, dormer and gable walls and a flat ceiling; and by insulating all of these elements properly a thermal barrier is created that prevents heat from escaping.