Hi can someone help please. A tenant has installed a boiler in a communal basement of a house converted into self-contained flats. The basement is divided into several small 'rooms' which are all communal. The boiler has been installed in one of these 'rooms'. The room itself is not compartmented properly. The ceiling of the whole basement is due to be made 60 minute fire-resisting shortly. I've suggested a detector to be installed within the room in addition to one located in another part of the basement, all linked to the Grade A system in the main house. They have questioned the need for the additional detector (the cost is high). Any thoughts please?