I have recently carried out some work on the bathroom in my house and
require some advice as to the applicability of building regulations. I
live in the UK.

The work I have carried out is as follows. Originally I had a bathroom
and a toilet separated by a partition wall, I have now:

1) Removed the partition wall between the bathroom and toilet to
create one large bathroom.
2) Replaced the shower, bath, and toilet with new units.
3) Blocked up the original doorway into the bathroom with a new
partition wall (so that there is just one doorway into the large
bathroom where the original toilet doorway used to be).
4) Moved the sink to where the original bathroom doorway used to be
and attached it to the original bath water supply and waste.

The local council's building control officer has now been to see the
work and is happy with everything apart from the fact that he wants me
to fit an extractor fan. The problem is that I do not want to fit an
extractor fan as the bathroom has two opening windows, which provide
plenty of ventilation, and it will be very expensive for me fit one
(for a number of reasons).

As I understand it building regulations currently require that all new
bathrooms should be fitted with a "mechanical means of ventilation".
However, having spoken to another approved inspector, he has said that
the issue of the extractor fan is somewhat subjective when it involves
an existing bathroom.

I am quite confused over the whole building regulations requirements.
My questions are:

1) Has the work resulted in a "new" bathroom or can it still be
considered as an existing, but altered, bathroom?
2) If I can find an approved inspector to certify the work without the
extractor fan fitted is this adequate? or could I still be subject to
an enforcement notice or fine issued by the council inspector?
3) If I appeal the council inspector's decision that I need to fit an
extractor fan what is the process? I would argue that opening the
windows are more efficient than the extractor fan and would waste less
energy. I think I could prove this but would this "proof" be
sufficient for me to overturn the decision?
4) Are you as confused about building regulations as I am? 

Thankyou in advance for your efforts,