The question is if there is nowadays better glazing that could be retrofitted and improve the thermal properties of what is fundamentally, in my opinion, incorrect construction.
In our house we have an (unfortunately) unheated "sunroom". That' a room that has three sides exposed, with 2m-tall, floor-standing windows for walls and a pitched, insulated roof. There is no ceiling per se, one can see the eaves, but if there was one it would have been
2-2.2m high (no thanks :-)). It is significantly (up to 1.5m) raised from the ground.We use this very infrequently, for the expected reasons; despite the black-out blinds in the summer it can exceed 35deg and in the winter my stingy heart aches to heat it with an oil-filled radiator (though it is on at the frost setting). In spring it can be unbearably hot during the day and still need heating in the evening.
It is double-glazed, with wooden frames and must be 10-15 years old. I have no simple way of extending the heating to it (wooden floors in the adjoining room and concrete/terracotta tile floor in the sunroom).
Thanks in advance for any ideas!
-- Kostas