Glass Room vs Wintergarden
Glass Room:
A glass room, like those on this page, has single glazed panels and is not insulated — there may even be small gaps between glass panels. It can thought of as a glass covered patio area. It can be a lovely place to sit on a sunny winter's day and in the summer the sliding glass panels can be opened up leaving just the roof. You can add an infra-red heater for a little warmth in cold weather.
Wintergarden (aka Glass Extension) VIEW PAGE
"Wintergarden" is a German term for an insulated glass extension. A Wintergarden is double or triple glazed and fully insulated all round — the addition of bifolding or sliding doors allow it to be opened up on a sunny day. It can be used as a separate sun room, like a conservatory, or the wall can be knocked through to create a glass extension to a room, becoming part of the home and used all year round.