Timber vs Aluminium windows acoustics

[Sjk]

Hi all

 

Sorry another question from me!

 

We need to choose our windows, the planners seem open to both timber and aluminium. 

 

So the issue is we are on a budget, spanking 25k on some quality wooden windows isn’t going to happen, it seems we can get some okay soft wood windows for about 7k which is approximately what we were quoted for some aluminium windows. 

 

Now, I prefer the wooden windows, but I’m worried they will let more noise in. 

 

Are windows rated? Is there a standard they must adhere to?

 

 

[MikeSharp01]

No particular standard for the window itself but they do have U values, so if doing a passive style house yiu have a U value to achieve and they need to meet building regs in all kinds of ways; air tightness, glass toughened where needed and escape provision. 

[ADLIan]

+1 on above.

 

I doubt the frame material has an impact on the acoustic performance. Acoustic performance depends mainly on number of panes, glass thickness (better with 2 or more different thicknesses), gap between the panes and addition of an acoustic absorber between the panes. Remember as soon as you open a window its acoustic performance reduces to zero!

[Moonshine]

1 hour ago, Sjk said:

Are windows rated? Is there a standard they must adhere to?

 

Yes they are/should be for sound reduction (Rw) in particular cases, this is not a building regulation requirement but maybe required from planning if its a noisy site, to achieve suitable internal noise levels.

 

Some manufactures will test in accordance with BS EN ISO 10140-2:2010, but you have to make sure that the quoted sound reduction (Rw) are for the glazing panels,  including frames and seals. A lot of things quoted are for the glazing element but not the frame.

 

A typical double glazed unit (6mm/12mm/6mm) will give an Rw 30-32 dB, assuming that frame and seals are good.

 

34 minutes ago, ADLIan said:

Remember as soon as you open a window its acoustic performance reduces to zero!

 

not quiet that straight forward, as depends how 'open' the window is, the source and window type

 

https://www.napier.ac.uk/~/media/worktribe/output-246785/twfrepnanr116pdf.pdf

 

[the_r_sole]

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Edited September 26, 2019 by the_r_sole

[Jeremy Harris]

I can add that our aluminium clad timber windows, fitted with 3G glazing (4 - 20 - 4 - 20 - 4, so 52mm thick glazing units) are extremely good at keeping out sound.  If anything they are too good, as the house is a bit eerily silent inside at times. 

[Moonshine]

1 hour ago, JSHarris said:

I can add that our aluminium clad timber windows, fitted with 3G glazing (4 - 20 - 4 - 20 - 4, so 52mm thick glazing units) are extremely good at keeping out sound.  If anything they are too good, as the house is a bit eerily silent inside at times. 

 

Chuffing heck that is some build up, was that selected for thermal reasons?

[Jeremy Harris]

7 minutes ago, mike m said:

 

Chuffing heck that is some build up, was that selected for thermal reasons?

 

Yes, they are budget passive house standard windows (£8,500 for all the doors and windows, including a big glazed gable) with a reasonably good thermal performance, around 0.7 W/m².K Uw.  It was only after the house was finished that we realised that they were also pretty good at keeping sound out.

[jack]

47 minutes ago, JSHarris said:

... a reasonably good thermal performance, around 0.7 W/m².K Uw.  

 

Only "reasonably"? I think you're selling them short!