roof lantern u-values

andrewf75

Hi all,
We're about to start (hopefully) building a kitchen extension with bi-fold doors and a large (3x2m) roof lantern. Obviously heat loss is something we are concerned about and want to minimise but in designing it we have been assured that with the best new technology glass, it won't be an issue.

What kind of u-values should we be looking at from the lantern and bifolds for the room not to be too cold? Is it worth going all out for tripled glazed 0.6 u value or are the double galzed argon filled ones with roughly 1.2 u value going to be OK? My instinct is to get the best there is as with such a large glass area I don't want to take any chances!

Anyone got any experience of lanterns/bifold doors? Company recommendations would also be greatly appreciated

Many thanks!

Rodney_Trotter

Just done it 2x2 lantern and a 4.5 bifold. Also have another patio door in the room. Its not been an issue.


What area are you in?

andrewf75

Nice one, thanks. I'm in Oxfordshire

Rodney_Trotter

A local company beat the internet supplies in the end. Try and find someone local who's got some experience in bifolds. Aluminium are considered to be the best, then upvc followed by wood. Others will no doubt have other opinions.