By constructing a glass Sun Room with Tiled Roof or putting such a roof onto an existing glazed structure means that it becomes and Extension.
Although many fully glazed Sun Rooms would have been exempt from Building Regulations, the introduction for a tiled roof at any time will bring these buildings under full Building Regulation Requirements.
This will entail Council fees of several hundred pounds, submission of Structural Calculations for the lower frame work, exposure of existing foundations and drainage together with producing overall thermal efficiency in relation to the whole building.
Full lead cavity trays will be required, there should be a heating system independent of the main home and any electrics must comply with Part L.
Failure to deal with all of the issues above correctly, will present extensive problems if the property is put on the market and it is important to be aware that even if Building Regulations are not required for a project, nonetheless compliance with many of the related issues is a legal requirements, which if not complied with can result in heavy fines and the probability of Enforcement Orders.
We offer the full services of an architect, structural engineer who is a heat retention specialist to ensure that your project is correctly and legally programmed.
You may well find that a completely new structure, possibly taking advantage of the existing lower walls and fully designed with Building Regulations from the beginning will be a better option.
It would probably also mean that the value added to your property is more than modifying an older existing structure and consequently the best value for money.