Excellent answers, all.

Thank-you. I will try to incorporate as much as I can. I know all about
poor ventilation in a flat that suffered from condensation. I installed
a heat-exchange ventilator that seemed to improve (reduce) the
condensation. I just hope I can find the instructions somewhere.

I intend to keep notes and post my experiences via a blog as and when I
commence on all of this.

I will have a period with "existing" setup so I will have a little
"baseline" info to compare the improvements against - although I won't
wait a whole year before starting work


Clive