Hello there - I have a 4 bed, 1960s built house which has previously had cavity wall insultation and doubleglazing added. Since moving in, stripping all wallpaper & painting, we're finding that the windows (especially upstairs) have quite a condensation issue and that we're getting slighty furry/dusty green mould growth on different surfaces even though all upstairs doors are kept open and the house warm...however, we don't have an extractor fan in the bathroom AND we can't open windows with ease as we have house cats...i've booked an app with a PIV installer but these seem really expensive and i don't know if they're worthwhile or if there are any different &/or cheaper options people coud recommend. Thanks.
