Central Heating? Oil filled radiator?

[Motorina]

I have recently got a new job working remotely. I've set up a study in a small attic room, but have only now realised that, whilst it has a radiator, it's not actually connected to anything. Due to, uhhh, historic bad plumbing decisions, the pipes literally end in the middle of a concrete screed.

It would be relatively straightforward to plumb it into the central heating system, but the alternative is simply to put a plug in oil filled radiator in that room. The former will involve a plumber, so have set up costs, whereas the latter won't.

My central heating runs on oil. What are the relative costs of heating a room with the central heating, and heating it with a plug in oil filled radiator? Because if there's not much in it I might as well go for the latter.

Thank you!

It will be cheaper to heat one room with an oil filled radiator when wfh compared to heating the whole house. When I wfh I’d never put the central heating on.

but if you’re going to have the heating on then running an extra central heating radiator will be cheaper than an oil filled radiator

Oh on gas central heating anyway. No idea about oil.