Since the heating V A/C war of winter 2012/13 (A/C won ..) and me ignoring the thermostat settings, dad getting whopping bill in 2013/14 winter , we have a new boiler and individual thermostats on radiators now.
10.30pm-6.30am the thermostat is set to 17ºC, 6.30am-9am it's 21ºC, 9am-2pm it's 20ºC and 2pm-10.30pm it's back to 21ºC. I don't have the radiator on in my room but the house is comfortable for father, which is fine for me.