Heating a lean to conservatory /smoking shelter in winter

[edlyu]

Joined to the house in a corner. Glass windows and door on two sides only with half brick walls to the front and side.Perpex double wall roof sheets.Ceramic tiled floor.

Has anyone any idea of the most efficient/economic way of heating this space to a comfortable (for short time spans only) level. I dont need it to be 'liveable' only bearable will do .Better than being outside anyway.

We have tried fan heaters and little oil heated radiators but they are either too slow to warm the space or burn out quickly if left on. Not possible to extend house central heating even if I wanted to.

What about a small portable Calor gas heater?
V. quick to heat up and they throw out lots of heat.
Only faff is replacing empty cylinders.

gas heaters create moisture.

Conservatories are exempt from building regukations requiring houses to be energy efficient and well insulated; and they aren't.

Trying to keep it as warm as a habitable room will cost a fortune. You could put a fan heater in it if you only use it for very short periods. It will be very expensive to run but quick to warm the air. If you have any chance of letting the sun get to it by pruning trees, that will help.

what about an electric wall heater ( they are usually in smoking areas in pubs etc), no idea if they are expensive to buy/run but they are very quick in warming areas.