Heating a lean-to office/man cave

[option click]

I'm in the process of building a timber-framed (fully insulated) room and was wondering what would be the most effective and/or cost efficient means of heating it.

Should I:

• extend the current central heating system?
• get an electric oil filled radiator (although the ones I've seen all look bulky and ugly)?
• get an electric fan heater - suspect this would be the most expensive to run?

All suggestions and advice welcomed - thanks

[sunbeam alpine]

If it's a true man cave fire is the only option.

[thinfourth2]

Get out the welding gear and make yourself a fire

That is what i did for our greenhouse