Required window U value, just the glass?

[epsilonGreedy]

When specifying new-build windows to meet building standards, do inspectors just focus on the manufacturer's quoted glazing U value or do inspectors want to see a calculation of a combined U value for glazing plus frame?

 

In my case I am talking about wooden sash windows fitted with high spec sealed glazing quoted as:

 

Glazing: D.G.U 24mm (4mm annealed - 16mm gap - 4mm soft coat Low E annealed)

✓ Glaze gap: Argon gas filled: centre pane U value = 1.1W/m2k

✓ Glazing spacer bar: TECHNOFORM "T.G.I" warm edge

[ADLIan]

Whole window is assessed - glazing and frame

[ProDave]

Whole window Uw value will go into the SAP calculations and that will pass or fail building regs.

 

Manufacturer should publish Uw values.

[epsilonGreedy]

Ok thanks both, not what I wanted to hear.

 

One bit of good news is that wooden windows only have to meet a U value of 1.6. I suppose I could try to argue that if the glazing has a U value of 1.1 the frame would gave to perform very poorly to drag the overall U up past 1.6

 

I will contact the importer of these Baltic sash window to see if they can provide a whole frame U score.

[craig]

Whole window value calculated to EN 10077-1