Thanks woody, I'll get her to do all that in future.Classic condensation.
Almost all of this can normally be prevented by taking simple changes in how the property is used, and all at no or little cost.
The moist air that settles on the walls is created by the occupants.
Extract steam at source from kitchen and bathrooms. Close kitchen door. Fit fans to these rooms and use them up to 30 minutes after bathing or cooking.
Open other doors to move air around the house
Use heating constant but low. Not high temp on/off cycles.
See other online condensation advice from reputable sources. Council housing department sites or Housing Associations have good advice as many of their properties have condensation issues and occupants with limited means.
What's your thought on that positive pressure device. Also the really bad area bottom of stairs he said might be rising damp?