DrChippy
Member
Hi everyone,
I'm considering sourcing some high performing timber windows from Germany through a Melbourne company called Sustainable Construction Services. They're higher performing than what I can get from Australian manufactures, and cheaper than some Australian manufacturers too. I was just wondering if anybody had any experience with this company and/or if anybody had any other experiences and recommendations regarding purchasing imported windows.
Thanks.
Bushwalker
Member
We've been doing this for several years with a different company, can recommend it. The quality is very good and pricing has also been competitive despite freight and exchange rate variations. I don't want to turn this into an advert for the company we have been using but we are very happy with them, PM for details if you are interested.
BW
DrChippy
Member
Thanks very much for your reply, Bushwalker.
Just another question for you (or anybody else who can help). The German-made windows I'm currently looking are double glazed timber windows with low-e glazing that have a U-value of 1.2 and an SHGC of 0.62. The u-value goes up to 2.0 without low-e glazing. Local manufacturers I've contacted can supply double glazed timber windows with clear glazing with a u-value of 2.2, which it seems can be reduced with low-e glazing, but not to as low as 1.2. And with low-e glazing the Australian windows have an SHGC much lower than 0.62.
Is everyone here using the same units of measurement, particularly for SHGC? If they are, what is it that the Germans are doing different?
John Doe
Member
Hi Dr. Chippy - I am going through the same consideration. I initially sought some pricing for triple glazed windows (U-value of 0.6) from Germany. The price point is prohibitive when compared to local AUS suppliers of double glazing (came in at three times the price).
I think the air gap, the glass thickness and the filling combo for local manufacturers is different to the ones overseas. The local manufacturers I reached out to use a 4mm glass/12mm air gap/4mm glass. The ones in Germany used the same thickness and air gap but had Argon.
Keep us posted ...
Bushwalker, I will PM you for the details.
Bushwalker
Member
Just be aware that you need to compare apples with apples. The German windows are precision built (ours were made in a computer controlled factory if I remember correctly). Attention to detail is super, air sealing is catered for with at least two really good seals and rebates to take them. Our glass is all double glazed, low-e, and argon filled. Windows arrive pre-finished in the timber you select with the colour or stain you select. etc.
You can get double glazed windows at bunnings. Surprise, they are not the same! There are quality builders of windows here in Australia, but in my experience, once you get to the quality of the EU windows, you are paying much more than the cheap frames available locally and probably more than importing. Worth checking out the differences.
FreddyBare
Member
There is a company that is apparently in partnership with a German company that manufactures in China, their quality seems good and their certifications are genuine, they're a lot cheaper than here too. German windows as beautiful and energy efficient as they are, are mostly overkill for Australian conditions unless you're living in an alpine area, I would have thought?
I have no affiliation with this company I'm just chiming in. I can let you know their name if you like, I actually received their name from a fellow ATA'er. 
Bushwalker
Member
FreddyBare said:
German windows as beautiful and energy efficient as they are, are mostly overkill for Australian conditions unless you're living in an alpine area, I would have thought?
As soon as you start expending energy to cool or heat, or storing energy via sunlight and thermal mass, improving the insulation is a worthwhile effort. If you do it right, you only have to fit windows once. Our place is pushing 65 years old and I can tell it is on it's third set of windows now. The first steel frame windows were replaced at about 25 years, and the second set of warped, rotting and leaky timber frames we started to replace when they were about 30 years old. I'd bet that each time windows were installed the builder or owner considered them to be fine for Australian conditions.
I think these windows will last well beyond another 65 years, and there is no comparison to the level of comfort in the home, then vs now. We don't live in an alpine area, we live in a high wind area where overnight winter temperatures regularly push down into the low single digits and summer highs into the high 40's. I don't think good quality, well designed and insulated windows are overkill at all.
arttt
Member
DrChippy said:
Is everyone here using the same units of measurement, particularly for SHGC? If they are, what is it that the Germans are doing different?
I think the units of measure are the same... sort of. There are some things to be aware of.
WERS, the rating system used in Australia, uses U and SHGC values for the whole window ie glass and frame together.The frame reduces the SHGC as its not transparent and the frame can increase or decrease the U value depending on the relative performance of the frame to the glass.
WERS has a set of standard sizes that windows are assessed at for example all awning windows in WERS are modelled with the same dimensions which is different to the dimensions used for some other window type. So you need to make sure your comparing whole window values and similar window sizes.
Even within Australia you need to be careful if your windows are way outside the standard modelled size.
viridian has comprehensive specs on their website for just the glass although its easy to misread some of the specs around lowE last time i looked at that document.
Also be careful with the BCA requirements around glass eg making sure glass is toughened etc where it needs to be. The rules else where in the world can be very different and can be lost in translation. I know of one person who had a big issue with this.
Ah the joys of windows! I can share what took me months to find out while designing and building a certified passive house following the International Passive House Standard.
U values of frame are important and the Germans use the EN standard. Australians use a different standard. You can't translate. If you use the EN standard to compare then ask for data in the EN standard.
U values of the glass same issue. We used triple glazed.
SHGC same issue. EN and Aus are different measuring tools.
Airtightness is crucial and the Aus windows in this regard are way behind.
Don't forget as out window connection details for thermal bridge. airtightness, and wrapping insulation.
Windows are one of the 5 keys for essential energy efficiency performance...
Regards
Fiona McKenzie said:
Ah the joys of windows! I can share what took me months to find out while designing and building a certified passive house following the International Passive House Standard.U values of frame are important and the Germans use the EN standard. Australians use a different standard. You can't translate. If you use the EN standard to compare then ask for data in the EN standard.
U values of the glass same issue. We used triple glazed.
SHGC same issue. EN and Aus are different measuring tools.
Airtightness is crucial and the Aus windows in this regard are way behind.
Don't forget about window connection details for thermal bridge avoidance
. airtightness, and wrapping insulation.Windows are one of the 5 keys for essential energy efficiency performance...
Regards
DrChippy
Member
Thanks Superpod. I was recently made aware of the different standards being used, but hadn't yet got around to posting my "discovery". One thing I'd be keen to know, however, would be if there was an tendency of one standard to calculate higher or lower values comparible to the other. From what I've seen, windows with values calculated using the Australian method seem to have higher u-values and lower SHGC values, even when the windows and the glazing seems almost the same. It's possible that there are some differences in the quality of the frames and the glazing that would account for this. However, might it also be possible that the Australian calculation method is uniformly producing higher u-values and lower SHCG figures compared to the EN method of calculation? Does anyone have any knowledge about this?
Hi DrChippy
I found that you couldn't make assumptions or convert EN to Aus u value or SHGC. And that Australian window frames will generally be much worse than European ie higher U values. But the only way to compare would be to test one window using both methods!!!
As we were complying with the passive house standard the Aussie numbers became irrelevant
What a complicated component!!
Johnnojack
Member
Stegbar 'Sightline' windows, wood on inside ally on outside. Thermally broken. Also shopping for DG windows. Not keen on the European rounded PVC frames. Have only seen a few so reading this with interest.
Annette
Member
I have several UPVC windows (two tilt and slide doors and a tilt and turn window). They were installed over a year ago and have been great.
Not sure what you mean by 'rounded frames'. Mine are German profiles assembled into windows here.
gazmo88
Member
FWIW we found a company in Sydney called Ecoline Windows who import most of their extrusions from Europe and manufacture them here with a very impressive CNC machine. They do pretty much all styles - tilt & turn, open out, lift and slide in several grades in both aluminium and plastic. They only do double glazed and do not do the timber / alloy composite windows.
They are attractively priced compared to comparable products, although I could not say how much of that was down to the large size of our order. You are buying direct from the factory.
none installed yet so the jury is out for the time being but the samples we saw are at least as good as anything else.
Cheers
Bushwalker
Member
Gazmo, are you getting decent seals with your windows?
I had a look at the Stegbar Sightline referenced above, and there is hardly a visible seal and no emphasis on sealing in the brochure. They offer bifolds which would be a nightmare to effectively seal anyway, maybe truly effective sealing is not on their priorities. The frame dimensions also look pretty light duty compared to windows from EU.
If I can find some comparison photos, I'll post them up.
gazmo88
Member
BW,
As I said we have not yet put them in. But the samples we saw had pretty good looking seals. Its mostly European stuff so it seems to be pretty well worked out. At least as good as the Rylock ones I'd say.
I'll let you know once we put some in. We have mostly gone for inward opening tilt and turn, a few lift and slide and some outward opening French doors.
Even their bifolds seemed to have pretty good seals but the basic physics is working against you with a bifold - I reckon any bifold will leak air eventually.
We looked at the Stegbar sightline but they did not seem very well made. I gather there has since been a change in the place of manufacture though so it may be better now - have not been back.
Was also sorely tempted by the Rylock timber / alloy composite but they stopped doing them and they were a good deal more expensive than ecocline for thermally broken double glazed.
Johnnojack
Member
Thanks Bushwalker and Gazmo, I didn't notice that the Stegbars had poor seals, but it is early days and haven't seen much else. By rounded frames I mean the profile is rounded and a bit bulky. As we use exterior sliding doors a heck of a lot I reckon the lift and slide type would drive me mad. Sure they seal tight but convenience of use is also very important. Pity about Rylock, (we do like Aluminium out and Timber in) I built with Rylock 30 years ago and they were so much better quality than everything else at the time.
Living in Adelaide is a disadvantage when it comes to DG shopping, not all Eastern states windows are easily available here.
Can anyone else who has had good or bad experiences with double glazing please chime in.
axess
Member
Hi Johnnojack,
We've been using Certainteed sliders (+one doublehung) for the last 14 years without any problems. One window was fitted with a lintel top clearance problem but still works fine.
Attention to sealing around the sills and frames seems to be the key from day one.
I'm currently looking at motorising (or at least using a hook on a long pole!)the northern clerestory windows to improve night venting and building a security door combo to allow the front door to stay safely open on hot nights. Although it did take us 13 years to fit the window sills (and 7 years to choose wall sconce lighting). Ah maybe next year!
Thesakaman
Member
Hi i am currently building my house and want to bring windows in from europe and was wondering if they comply with our australian standard and will pass. If anyone has done this or knows anything about it your help would be much appriciated
When looking at Thermal Ratings/Figures from imported systems from europe, just keep in mind these are likely to be assessed under "CEN" testing conditions. In Australia, we utilise the American condition criteria "NFRC" for thermal assessment. That means you are not comparing apples with apples.
Basically for U-value assessment, CEN coniditions are 0deg external and 20deg internal.
NFRC Conditions are -18deg external, 21deg internal. There are also other differences like wind speed/velocity.
There are also major differences in SHGC values between the two conditions.
There is a good thesis paper completed by Peta-Gaye Ebanks, from Trent University which analyses the differences in results when utilising these different assessment conditions.
He found; "Uframe values differed where the NFRC U-values were found to be 5% lower to 24% higher than CEN values."
More reading for those that are interested by googling;
"A COMPARISON OF THE NFRC AND CEN THERMAL TRANSMITTANCE CALCULATION METHODS IN NORTH AMERICA’S
EIGHT CLIMATE ZONES"
Thanks,
Kurt Miglas
Miglas Windows
Benny said:
Seems odd Kurt that we use the US system - -18C outside ??? We don't often have that here.
I think it's more to do with Australian Fenestration Rating Council (AFRC) being the Australian 'arm' of the National Fenestration Rating Council (NFRC - USA) rather than the climate here. They follow their principles. But on the same note; Europe would frequently see below 0deg C...
https://www.wers.net/werscontent/about-wers
About WERS:
... The computer modelling software is the same as that used by the U.S. National Fenestration Rating Council (NFRC). It has been thoroughly validated against laboratory tests in all climates, hot and cold. WERS is truly international in its heritage and draws on over 100 person-years of research and development in 15 countries over the last decade...
Thanks,
Kurt Miglas
Miglas Windows
DrChippy
Member
Hi Thesakaman,
I got my windows from a company that imports them from Germany. My building surveyor, who has generally been by the book in terms of his requirements, only required of me a letter from my supplier that stated the windows were up to standard. My supplier supplied the letter, and that was that. In terms of performance, my surveyor doesn't care what method was used to calculate their performance. If you have a surveyor maybe ask them what they would require, then you could check with suppliers that they can do that provide the documentation you need.
AndyG
Member
My biggest concern with European windows has never been U-values, SHGC's, air tightness etc as they should be superior to local windows anyway - although be careful with SHGC's as imported windows may have SHGC's that are well above what is ideal for Australian conditions - but rather has been UV resistance.
UV levels in Australia are far above European levels and the last thing anyone would want is for their beautiful new UPVC windows to fail prematurely due to our harsh summers.
Otherwise, I would expect the European windows to be superior in pretty much every respect
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