+1 Théière on insulation.
I insulated our single storey house, which has 120 m2 of living area plus another 115 m2 of utility and storage space under the same roof, with 4 cm extruded polystyrene below the OSB + laminate floor, 4 cm polystyrene backed placo plus 5 cm fibreglass on the outer walls, and 30 cm cellulose above the placo ceilings.
Now our pellet stove tends to overheat the living area in mild weather, even on its minimum setting of 3.2 kW.
It tends to cycle on and off too frequently, which causes excessive soot buildup and shortens the life of the igniter element.
It is more economical (and quiet) to use our two 0.9 kW input / 2.8 kW output reverse cycle aircon/air source heat pump units when the outside temperature is above about 8 - 10ºC.
The only snag is that neither heating system operates when the electricity supply is cut.
Fortunately we are in a small town, not out in the wilderness, power cuts do not usually last too long, and we can run a petrol driven generator in the garage to provide power for lights plus the pellet stove.
EDIT: We were reminded of how effective our insulation is last week, when we stayed in a studio apartment in the mountains in S. Spain.
The days were mild, with temperatures around 18º, but dropped to 5º or lower at night.
The apartment had a huge radiator, with a slightly smaller one in the bathroom, fed from an oil-fired boiler.
These would have been enough to heat our entire house, but in the uninsulated building, they were barely adequate, and the floors were extremely cold.
I don't think there is much chance of slowing global warming when the majority are not even aware of the benefits of simply insulating their houses, let alone reducing the use of fossil fuel in oversized vehicles and home heating.
On some great and glorious day the plain folks of the land will reach their heart's desire at last, and the White House will be adorned by a downright moron.
H. L. Mencken 1880 - 1956
Some may not like his views, but what a prediction!