If the external footprint of your proposed conservatory is less than 30m square then you do not require regulations, if over 30m square then it does.
If you intend to open up the patio door or a window to create a through room into your conservatory then it DOES need building regulations, a conservatory should be seperated from the main dwelling by means of external doors to avoid building regulations.
If you want a tiled roof on your conservatory then the complete structure is likely to be less than 50% translucent and will therefore need building regulations.
All planning approval and building regulations will be dealt with by the company. We will also advise what they will need and follow the process from start to finish.
If you want to install a radiator running off your existing boiler which heats the rest of your home then it needs to be independantly controlled otherwise you need building regulations.
The specification for a conservatory and the basework to meet building regulations is much higher than a normal conservatory and will cost considerably more money.