Got to disagree with you on this one builder, which is a 1st.
Yes, there will be water carrying pipes that are not within the vicinity of either boiler or radiators which will be more susceptable to freeze than others. But by having the heating system come on especially when the internal temperature drops to approx. 15 deg c., the fabric of the building is warmed by the boiler, rads, and system pipework, and will eventually sustain the temperature around any zones where there are water pipes.
At present, I have the heating on throughout the night with the room stat set at 15 deg. c., and would be very upset if any of my pipes froze.