Heating for a small conservatory

[ANewDoll]

I am looking for ideas for economical and efficient ways of heating a small conservatory which is 10'2" by 7'3". It leads off the kitchen which has a gas central heating radiator and is separated by a glass door. I am hoping to use the conservatory as a small diner. Any ideas would be gratefully accepted.

Oil filled radiator which is portable and plugs into electric but cheap to run?

Or a wall mounted radiator which plugs into electric

Anything that runs off electricity is going to be close to 100% efficient in turning electrify into heat, so it doesn’t matter what you get. Something with more watts will bring the room to the required temperature faster.
Convection/ fan heater heat a room faster while raddiant heaters( oil filled for example) stay warm after they are switched off.

Bear in mind that a conservatory is treated as an outbuilding, not part of a house.

That means it doesn't have to meet Building Regulations such as cavity walls and loft insulation. It can be a well-insulated as a garden shed or a greenhouse.

That makes it cheap to build but expensive to heat.

Even a small one can lose 3kW of heat through the roof on a frosty night, which means you can put a powerful fan heater in there, using 50p worth of electricity an hour, and it will never actually get warm.

Maybe you have a well-insulated conservatory, but it's unlikely, especially the roof and the glass in the walls.

So your need for "economical" may not be met unless you invest in thick socks and jumpers.

We put underfloor heating in ours but cost a fortune yo run. so bought a couple of wall mounted convection heaters. they have fan boost and thrrmostat and work really well