Quote from Building Regs Explanatory Booklet:

"A porch or conservatory built at ground level and under 30m² in floor area
is exempt provided that the glazing and any fixed electrical installation
complies with the applicable requirements of the Building Regulations (i.e.
Part N 'Glazing - safety in relation to impact, opening and cleaning' and
Part P 'Electrical safety')."

So what about glazing with respect to U-value etc.
And do I still need a building notice. If so, I guess I just chat to
the BCO about
requirements.

Simon.