I agree with the FSO's comments that the provision of detection in WC's & sluices is over the top, (irrespective of whether its his call or not surely he or she can voice his or her opinion), i've seen a "dado-rail" of call points in a corridor in my time in order that the alarm installation company gets a holiday in Maritius.
Yes good point that there is a possibility of fire setters with people suffering from mental illness or dementia, but you can provide early detection in the MoE corridor and you can't beat a waking staff walk around.
Digressing slightly, but on the subject of residential care homes, I risk assessed one recently that had a nursing unit dedicated to one floor, when I asked to look inside the store room at the end of the corridor that was locked, I was told "That's only for our linen and paper towels etc" says the manger, when I finally got to look inside, it also had 48 oxygen cylinders in it - result! (It did have a detector in it though!)