as part of an ongoing kitchen renewal contract for a council we come across some houses fitted with outside taps and none have double check valves, we are instructed to reconnect them when we alter the plumbing to the new sink, but do we need to fit double check valves as we are "fitting" the tap today, or are we working on existing and can simply repipe into the existing pipe, like gas work i say if we reconnect it has to be done to todays regs and needs a check valve, Clerk of Works wont issue works order for the check valve, my arguement is they should have one which we could connect on to what do you guys think?