Conservatory or Orangery - which is greener?

[LucyJam]

I was planning to add a conservatory to my home but the company I am dealing with has suggested that I should think about an orangery instead as I am keen to make it as energy efficient as I can, not to mention being a bit less expensive on my fuel bill. They are a lovely company, and reasonably priced, I just wanted a second opinion on whether having a new orangery made with energy efficient glass and with a lower glass ratio is the greener option for me?

[welsh brickie]

its the glass thats the key,the frames are the same.You can buy low E glass but it will be extremly hot in the summer,The best on the market in my opinion is pilkington activ self clean."google" pilkinton glass for more information

[andy01]

A conservatory should not be used all year round as they are too hot in the summer and too cold in winter. heating them is effectivly the same as a garden heater, very wastfull
Also an external grade door must be fitted between the conservatory and the house.
This is not a requirement for an orangery. which goes to show what building regs thinks of conservatories.
build an orangery as it will have a better performance, but i imagine will cost you more as well

[ambusch]

A true orangery will be more energy efficient because it will often be built with structural columns (ie brick walls), and it has a large ceiling on which the roof (the glass roof lantern) is sat. This ceiling area will be designed to meet building regulations re energy efficiency etc....
The choice of glazing for the roof and windows / frames is the same for orangeries and conservatories. Basically go for a high performance glass that has low U-Value (the lower the better, it stops heat escaping) and also has good heat protection (ie reflect heat from the sun to make it more comfortable in the summer).
Currently Celsius [url](http://www.celsiusglass.co.uk)[/url]has the best performing performance glass (look up Celsius ELITE, it has a U-Value of 0.9).

So really it isn't just about choosing an orangery over a conservatory, but making sure that if you are going to go for the orangery it has all the right specifications that will make it more energy efficient (wide internal soffit with warm roof construction being key) Otherwise just go for a conservatory with good glass, and opt for a dwarf wall version. And let's be honest, some form of heating will be required

[LucyJam]

Thanks for all your responses, that's really helpful. It sounds like an orangery with good quality glazing is the best option, if the money runs to it. Building regs, as ever, make absolutely no sense at all. At least I'll be able to talk a bit more sensibly to the company I'm probably going to deal with - they seem to know what they're doing.