Why do I have damp problems after installing new windows?
As people have said,new windows have sealed out draughts,so now you have to let in fresh air,try putting windows on vent position,occasionally opening fully. You could also collect those silica gel sachets that come will lots of new things to keep from getting damp,place them out of reach of little ones where your getting damp,these help soak up moisture from the air,open bathroom window after bath/shower,kitchen after cooking,bedroom when you get up,basically any moisture needs to be replaced by fresh-air.
Sounds as though it is condensation, exacerbated by lack of ventilation, new windows aren’t draughty!! Try leaving doors of rooms open to circulate the warm air from the rest of the house, pull furniture slightly further away from the walls. Wash the affected areas of walls with a mild bleach solution. On nice days open the windows slightly to let fresh air circulate. If you have a dehumidifier put it on for a couple of hours, or use a crystals type moisture absorber, only a couple of pounds.
