I'm thinking of buying a house which has a UPVC conservatory.
I've never lived in a house with a conservatory before. But my
perception of conservatories is that they a

* Boiling hot in summer
* Full of condensation in winter; need loads of heating

What are the "real world" experiences of people on this NG who have a
UPVC conservatory?
For instance, could I comfortably sit in the conservatory on a winters
evening without feeling chilly?

Thanks
Bruce