plz help out of mind with worry about getting sued

GDB2222

Unless there are serious structural defects, mould is mostly caused by the people living in the place. Any flat needs to be heated and ventilated. Of course, colder walls and single-glazed windows will tend to lead to more condensation, but that is easily dealt with by a little ventilation and possibly quite a lot of heating.

An example is a flat I let to the local council in a seaside resort. The people they housed there could not afford to heat the place properly, and the result was mould in some places on the walls. It was a 100 year-old victorian property without cavity walls. I tried what I could to sort the problem, including replacing the render on the outside of the building, just in case it was defective somewhere. (It wasn't, and the problem persisted.)

In the end, the council housed their family elsewhere, and I sold the flat to an owner-occupier. I bumped into him a year later and asked if he had any problems with mould at all. He was genuinely puzzled, and his answer was "No, of course not!"