Different types of conservatories and when is one not
A conservatory is classed as having 75% translucent material in the roof and 50% in the walls. Anything less than this and it is classed as an extension and requires full Building Regulation approval. The downside of this is the additional cost in complying with the regulations, particularly with regards to the foundations. It must not exceed 30m2 of floor space, must be thermally separated from building it is attached to and have an independent heating system from the main building.
Can I put a proper roof on my conservatory?
The chances are that you cannot because the conservatory is unlikely to have been constructed in a suitable way as to accommodate a normal felt, slate or tile roof. You might consider removing the structure and starting the walls again to accommodate the roof, but it will need to have suitable foundations. It is quite possible a conservatory will not have suitable foundations so these will need to be installed basically turning your project into the building of a new extension.
Baileybridge build all manner of conservatories, orangeries, garden rooms and extensions and can advise on the pros and cons of each approach.