I have had an extension to mthe rear of my house and also the front (kitchen, downstairs toilet and ahll extendet to front of house. The house is c21 years old with UPVC double glazing and cavity wall insulation (as are the new extensions). The house feels cold and draughty despite the window people coming out several times and saying the seals on the windows and doors are fine. We had a new vented extractor fan for the cooker on an external wall and the plastic flaps move vigorously in windy conditions. Could this be part of the problem? I cannot get up to see if this is the problem. In the ensuite shower room I can feel a real draught coming through the door also and I feel a cold draught on my face when lying in bed. Could all of these things be connected? The bedroom door will actually move in real windy conditions but I can't actually feel a draught through the windows. Anybody got any thoughts please.

It is totally obvious that your home has many cracks or opening to allow outside air to lleak inside. Call 3 contractors who spcialize in making ahome weathertite. Listen to what they say and what they will charge. Then you can descide if you can handle that work or not. Let the pros do the looking for you.