@Justine413, Your location in the UK will likely have standard Heating for Homes requirements under various provisions of Legislation, including Building Codes.
May I ask what year it was Built and if there has been any renovations / alterations done to it, e.g Wallpaper/ Carpet added/ removed?
It's generally a Rule of Law to ensure Living areas are heated to around 18 to 20 degrees when sitting down, kitchens if they have opening windows with natural sunlight don't need to be heated if it's an enclosed type of room e.g a standard Kitchen because one is standing up and working in it, whereas Open Plan Rooms tend to require more warmth in colder weather.
Have you undertaken a Temperature check to see what the rooms are normally in the cooler months?
Maybe do that to as you will know what size Heating appliance would be best to suit your home.
Do you have Thermal or heavier curtains to retain the warmth, or lace/ net curtains for added warmth and ambiance?
A rug/ carpet?
There's nothing nicer than retaining the original features of your home to create warmth.