U values for doors/ceiling lantern. Advice needed!

Timmy C

Just getting quotes for doors and a roof lantern for a kitchen extension. Total room area is approx 38 square metres with approx 7.5 m of floor to ceiling folding doors across the back, 2.5m on one side and a 3x1.5m roof lantern.  I have no idea whether this information is relevant to my question or not but it gives an idea of the room. I hope to have it heated with water underfloor heating if cost allows.

The quotes I've had so far have stated a U value of 1.2 for both doors and ceiling lantern. My question is, is it sensible to look at a lower U value or is it likely to be a case of much higher cost for very little benefit? I can't help but feel everyone is out to sell me what they think I can afford and are giving me advice accordingly so any tips anyone could give would be very much appreciated.

John

I asked something similar in GC 18 months ago. will see if I can find it

C Rated Windows Vs A Rated windows | AVForums

Can't remember what I went with in the end. I think if I was having a roof lantern I would want it as efficient as possible