I've come accross housing associations that have L1 fire alarms in their contract spec for new builds - I have no idea if its a result of risk assessments in other buildings where there are compartment issues and they've made it a blanket policy, and they go a bit nervy when you suggest they take it out. as with many H&S issues, there is the assumption that the more you put in, the safer it must be and if you put the maximum in then everything is covered so it won't come back on the manager responsible.
I have seen BCO's and Fire Officers collude to try and get full fire alarm systems in new blocks - they try and use the 'we'll get you under the RRO' line to spook people - also had to deal with them trying to get disabled call points and refuges in buildings with no on-site manager (apparently, no staff was a reason why the intercoms should be there. No word on who was supposed to be at the other end)