My kitchen is a small extension (5 or 6 square meters) of the house. No heater. Extremely cold in winter (down to 8 degrees celcius). For months I've wondered why it's so cold (1), now I suspect it's the outside walls: the kitchen walls are about 80% or 90% outside walls. Can this explain why the room is so cold, and if so are there things I can do about it?
(1) I already posted a question here about why my kitchen is cold. But since the reason I'm proposing now is so different and calls for a different kind of answers, I thought posting a new question was more appropriate than adding comments to my old question.