The first measure is to dress your property in a good coat to reduce its energy needs. To do this, you have to make it airtight and insulate. If you see daylight under the doors that open outwards, if the curtains move a little when it's windy, it's probably time to replace the frames and doors. Be careful though, if you make your house airtight, the air renewal will have to be ensured by ventilation, otherwise you could encounter humidity / mold problems. Regarding the insulation, it can be placed under / on the roof, on the exterior / interior walls, on the ceiling or on the floor.
All these measures are to be evaluated on a case-by-case basis according to the cost and what will be the most beneficial.
Then, in terms of heating means, exit the oil boiler, the gas boiler is no longer the best choice either. Choose a heat pump or a pellet heater.
Finally, why not produce part of your electricity using photovoltaic panels? The return on investment is between 7 and 8 years.For the 3 categories, you will be able to benefit from subsidies.Need advice? We can refer you to professionals.