I work from home two days a week in an attic room office. To have this room heated in the winter I had to turn on the central heating for the whole house which seemed such a waste or turn every other radiator off manually.
The solution that I came up with in the end was to zone the house into four zones which can be independently heated. To do this I used Honeywell CM927 wireless thermostats connected to Honeywell V4043H motorized valves. The valves were installed by a plumber and he had to find points on the existing pipework where the pipes supplied the zones that I had identified. He had to cut into the pipes to fit the valves so the whole system had to be drained and it took a whole day.
The original central heating timer and thermostat are still there and these now turn the whole system on and off. Each zone has a wireless unit that can be used to set the times and temperatures of heating in that zone whenever the whole system is running. It's all worked perfectly for the last year, my gas bill is down by 15% and my office is warm for the first time.
The parts cost £560, the labour was £300 and I'm saving £120 a year so this should pay back in just over seven years.