Just to clarify, there is a difference between a conservatory and a glass room, with the latter tending not to require planning permission (although it is always good to check on with your local authority on this matter so you don’t end up having any problems because of building violations).
Glass rooms also provide the perfect solution maximising your abodes useful space. You could extend your kitchen with them then add both heating and ventilation so that all year round it will accommodate the fluctuations in temperature. You can also get reflective seamless glass that gives the impression that it’s only one sheet that you can see out of yet people will not be able to see in.