Green Building Forum - Alu-clad wooden window quotes received - help me decide please

Alu-clad wooden window quotes received - help me decide please

Monty Gerhardy — Sun, 30 Aug 2009 22:19:56 +0100

Posted By: MarenPrice Update:

The U-value for these alu-clad, double glazed windows is given as 1.4 (average), these are the only windows
built 6-22-4 with warm spacer (and argon filled).

Monty: thanks for your concern. I posted the Nordwin catalogue in response to valasay to show that Nordwin was the particular name given by the Hermann-Gutmann-Werke to the same aluminium profiles discussed earlier (Braga and Mira) as made specifically for the Scandinavian/British market. You are right of course that this says nothing about the actual timber frame or glazing units.

Do you have any insight on the Rationel windows?

22mm is quite a bit wider than the optimal 16mm cavity for argon filled units resulting in poorer centre of glass values â€“ 1.2 as opposed to 1.1. The Rationel website is not particularly helpful as it provides the same u-value for a whole slew of window types leading me to think they are giving the data for a fixed light (more glass, less frame, minimal air leakage).

My concerns are directed at the particular company mentioned in connection with the importation rather than the Nordwin system. Fortunately the introduction CE marking, which will show the manufacturer amongst other things, will take care of this issue early next year. Anybody buying imported windows that are not CE marked would do so at their own risk.

They are good windows. A few points to consider;
If you require the Secured By Design standard then it is an upgrade. So are fully reversible windows. This specification may be different in the UK market.
One irritating issue with these windows is the propensity for the external glazing gasket to work its way loose. Iâ€™m not sure if this has been designed out yet but itâ€™s not an un-common site here in Ireland to see the gasket dangling in the breeze.

Monty

Alu-clad wooden window quotes received - help me decide please

Maren — Mon, 31 Aug 2009 11:56:27 +0100

Thanks Monty, your input is much appreciated. Have just spoken to the supplier for the Rationel windows and was told that the 22mm gap was a structural necessity for the aluminium clad range (ALDUS) and that the all-timber windows (DOMUS) would routinely be quoted with a 16 mm gap. Rationel are the only manufacturer so far to have this requirement for a 22 mm gap.

They did calculate the U-windows separately for most of my windows, giving Uw of 1.38 for the smaller windows, 1.41 for the side lights to the French Doors and the tilt and turn door and 1.44 for the French Doors. No calculation for the double windows but they would probably be between side lights and French Doors. (This is all for the double glazed units with a warm edge spacer)

Rationel also claims to be fully accredited for the CE mark so are these windows/doors quality tested already?

Alu-clad wooden window quotes received - help me decide please

Monty Gerhardy — Mon, 31 Aug 2009 23:01:40 +0100

There is no question about the quality of Rationel products and they certainly do have CE marking in place. Itâ€™s the like of Rawington who I would like to see certification for.

Rationels U-value information is not exactly a model of clarity though.
The CE marking on their website gives a standard u-value of 1.3 W/mÂ²â€¢K for an ALDUS sidehung window, yet qualifies this with â€œThe value is calculated for a single window 1230 x 1480mm with Rationel 4-24-4 standard glazingâ€ (The maximum width that they will actually make a sidehung window is only 948mm!) Their architects brochure though states u-value for a â€œstandard ALDUS size (1230x1480mm) is 1.44 W/mÂ²â€¢K.

I know this may sound pedantic but to anyone familiar with these issues something sounds a bit odd. A 24mm cavity using a Pilkington SN or S3 coating (they may be using a Guardian 1.0 IGU but again their published g values - 0.63 - donâ€™t support this) will give a centre of glass u-value of 1.1 with a 16mm argon filled cavity. Increase that beyond 20mm and the u-value goes out to 1.2. Its very hard to see how they can achieve a whole window u-value of 1.3 when the glazing is coming in at 1.2. Unless of course they are using the data from a fixed light somewhat larger then 1230 x 1480!

I would be curious as to what third party certification there is for the unit u-values you were given. You might ask the supplier to check.

Anybody else have any suggestions as to how they are getting these u-values?

Monty

Alu-clad wooden window quotes received - help me decide please

fostertom — Tue, 01 Sep 2009 00:17:43 +0100

Yes, there's a lot of very curious Uw/Ug data out there on manuf's info sheets - and it goes both ways - the over-optimistic and the ridiculously pessimistic.

Alu-clad wooden window quotes received - help me decide please

Monty Gerhardy — Tue, 01 Sep 2009 21:31:19 +0100

As the industry adage goes â€œTell me the result you want and Iâ€™ll tell you where to do the testingâ€
Iâ€™m surprised that youâ€™ve come across people under-estimating â€“ its not an industry renowned for selling itself short.

I had hoped CE marking would clarify this issue but given the Rationel example (and others) it doesnâ€™t look that way. The continental manufacturers by and large take the EN10077 standard of 1230x1480 and measure a single light. This is not a problem with tilt/turn windows or some of the H-Type hinges unlike outward opening casements typical in the British Isles which would have a problem supporting a sash of that size. UK manufacturers stick to the GGF 2.2 configuration of a 1230x1480 frame divided into an opening sash and a fixed light as suggested in BRE 443.
A single fixed light will typically perform better then a single opening sash which will perform better then a combined sash and fixed light (due to a combination of perimeter air leakage and glass to frame ratios).

BFRC certificates are going to muddy the waters even further. PVC manufacturers may well certify a product with minimal reinforcement â€“ to get a lower u-value â€“ and then end up having to insert steel reinforcement to get a stable window.

Monty

Alu-clad wooden window quotes received - help me decide please

fostertom — Wed, 02 Sep 2009 13:57:26 +0100

Posted By: Monty Gerhardysurprised that youâ€™ve come across people under-estimating

yes, like Uw 1.4 for a 3G timber window - I'll try to remember who.

Alu-clad wooden window quotes received - help me decide please

Monty Gerhardy — Wed, 02 Sep 2009 20:46:27 +0100

Uw 1.4 is not that far of what what I would expect to see for 3G without the argon and a mid-performance coating on one pane only on a 1.2m x 1.2m window.
Chances are its something you saw in an oldish scandinavian catalogue.

Monty

Alu-clad wooden window quotes received - help me decide please

fostertom — Wed, 02 Sep 2009 23:22:50 +0100

No I think it was a newly-introduced UK state-of-art (by UK standard) thing - also yes one of the scandinavians.

Alu-clad wooden window quotes received - help me decide please

Kombi — Mon, 21 Sep 2009 20:42:57 +0100

Maren,
any news?? As I am in a similar situation to yours I am following with interest.

Alu-clad wooden window quotes received - help me decide please

Maren — Tue, 22 Dec 2009 13:57:04 +0000

Sorted, at long last!

Have just ordered my windows from Rationel for delivery first week in February. As we had to include another window in our order we decided against the aluminium clad windows in the end and went for the Domus range instead.

Having seen both the wooden and the alu-clad window, I was impressed with the solidity of the units, the workmanship and the finish. Window frames are 115 mm thick, doors 70 mm - much better than the PVC-U ones we also decided to have a look at.

Regarding the alu-finish: The sample window (alu-clad) spent two weeks in my house, hidden so the kids couldn't damage it. Nonetheless, when I got it out to return it I noticed a bent corner and a dent in the cladding, with the colour threatening to flake off where it was dented. I came to the conclusion that alu-cladding is ideal if you have very careful installers and nobody touches your units after installation. As we have three very lively kids and a temperamental builder, alu-cladding is not for us after all. We were still somewhat torn because of the low maintenance until we had to add on the extra unit and then went for Domus (all-timber instead).

Final cost excluding VAT was 291.50 pounds/sq m - (I calculated that just for you fostertom, but you are right it makes for a much better comparison.)

Sorry everyone who recommended triple glazed - that was an extra 20% we didn't have. FYI alu-clad was ca 13-14% more. Whole window U-values achieved range from 1.33 to 1.55 depending on the size and type of units.

Thanks to everyone who gave their time and advice and so helped make our search for the ideal windows and doors less frustrating and confusing allowing us to make a much more informed choice. Much appreciated.

If you have any questions, I'll be glad to help.

Regards,
Maren

Alu-clad wooden window quotes received - help me decide please

Tuna — Tue, 22 Dec 2009 15:33:22 +0000

Posted By: MarenRegarding the alu-finish: The sample window (alu-clad) spent two weeks in my house, hidden so the kids couldn't damage it. Nonetheless, when I got it out to return it I noticed a bent corner and a dent in the cladding, with the colour threatening to flake off where it was dented. I came to the conclusion that alu-cladding is ideal if you have very careful installers and nobody touches your units after installation. As we have three very lively kids and a temperamental builder, alu-cladding is not for us after all.

That's interesting - we had a sample 'corner of a window' that we sent to planning, and that then kicked around our house (literally) for about six months before we swapped it for a set of full size ones. During that time, the aluminium remained dent free and the paint remained intact. The full size units made it on a ferry from Europe and across a field via an agricultural low loader without incidence.

Alu-clad wooden window quotes received - help me decide please

Kombi — Tue, 26 Jan 2010 23:09:45 +0000

Hello Maren,

I'm glad to see you are sorted. I wish it was the same for us sadly not!!! We wanted a sliding window in timber, with 3G. Unfortunately our chosen supplier let us down about 1 week after delivery was due, telling us that unfortunately he cannot make the window!!! So we are back to square 1almost, but time is pressing on as the work has stopped due to the lack of window.

If anyone knows who can make a 2400x1090mm window, divided into 4 panes of 600mm, with the 2 centers panes sliding left and right to create an opening (a bit like a double patio door), in timber or timber/alu and 3G then please let me know asap.

Maren, let us have your comments when the windows arrive.

Alu-clad wooden window quotes received - help me decide please

CarneyC — Wed, 27 Jan 2010 13:40:32 +0000

Kombi,

Try these people

http://www.sunparadise.co.uk/

I know some of their profiles can be triple glazed, they may have something suitable. We used them for some slidyfoldy doors & were very happy with the product.

Best of luck

Chris

Alu-clad wooden window quotes received - help me decide please

Kombi — Thu, 28 Jan 2010 01:13:41 +0000

Thanks Chris, I'll give them a try.

Alu-clad wooden window quotes received - help me decide please

Maren — Fri, 29 Jan 2010 01:18:28 +0000

Kombi,

sorry to hear about your problems, our windows are expected for the week starting 15 Feb so we're still waiting.

Just had a quick look through all my quotes - Albo Uk and Nordan quoted for a triple glazed door set similar to the window set you require, Rawington was double glazed - can't remember if they could do the triple glazed sliding. Our 4 sections were 700 mm each, though, and a number of companies told us they could not make sliding doors that small due to the weight I think - which is why we went with the french doors instead (also worked out at least Â£1k cheaper for the manufacturers who did offer this door set)

Hope this helps.

http://www.albo.co.uk/
http://www.rawington.com/
http://www.nordan.co.uk/UK/index.php

Alu-clad wooden window quotes received - help me decide please

ardachaidh — Sun, 17 Oct 2010 16:12:47 +0100

Maren, can you give us an update on your windows, and whether they have met your expectations?

Alu-clad wooden window quotes received - help me decide please

Peter65 — Thu, 20 Jan 2011 21:16:03 +0000

I found this thread extremely useful when starting my search for windows last summer for a major self-build refurb project, thank you Maren for the original comparison of suppliers. I spent a long time researching and selecting my windows, 6 alu-clad timer, 2 external doors and french doors, approx 14 sq m total, plus 2 roof-lights. Roof-lights were easy, only Velux offered the spec, size and finish I wanted, and Jewsons gave me the best price.

My initial request went to most of the list Maren mentioned, plus a few others. I was impressed with the speed of response from Nordan, Rationel, Rawington, Russell and Velfac, with most quoting within a few days, despite it being summer holiday period. Some of the other suppliers were much slower, but it took me longer to select a window with the normal delays caused by changing the size and location of windows.

I was looking at design and quality of windows and doors, plus confidence in the supplier, with price not a major consideration provided it was within my budget - I was asking for supply only with option for fitting. After viewing windows (I live within an hour or so of showrooms for RationeI, Rawington, Velfac and Nordan, and visited an impressive Adpol project) I reluctantly dismissed Russell as there were no windows or projects I could see locally, as well as Adpol as the appearance of the windows just wasnt to my taste. Nordan, especially the doors, were expensive but extremely high quality though I thought the others looked better. Eventually Rawington offered a superior design, not in their catalogue, with central mullion to match other older windows. My original spec inevitably changed, notably to a sliding patio door as well as the central mullion on the windows.

Prices? For the original spec there was a wide spread, from Â£310 to Â£550 per sq m. Rawington quoted Â£410 per sq m. All these were plus delivery, installation and VAT.

I placed order in end October. My windows were ready within the stated 7-8 weeks but bad weather prevented delivery until early January.

What impressed me about Rawington? Technical support before order was excellent, with most emails answered the same evening. Information on delivery arrived without having to ask for it, and I was even sent a picture of the completed windows ready for despatch. Installation was meticulous on a Sunday and Monday, and a return visit offered to carry out adjustments - there will be a few, but nothing major. Window quality and finish is as good if not better than their showroom windows, and upto the standard of the Velux windows. (My job was in manufacture of building products)

Negative points? Compared with Nordan, Rationel or Velfac, Rawington are a much smaller operation in UK, so the comfort factor is lower, but offset by the ability to deal direct with the person that runs the UK operation.

Having seen a lot of windows, if I were starting my search again, I would limit it to windows I could see, because I found the windows had to be viewed to compare appearance and ease of use.

Hope this helps the next person looking for windows!

Alu-clad wooden window quotes received - help me decide please

marktime — Thu, 20 Jan 2011 22:22:45 +0000

Very helpful. Thanks for posting.

Disclaimer: No connection with Rawington's

Alu-clad wooden window quotes received - help me decide please

Monty Gerhardy — Thu, 27 Jan 2011 22:45:39 +0000

Posted By: Peter65
Eventually Rawington offered a superior design, not in their catalogue, with central mullion to match other older windows. My original spec inevitably changed, notably to a sliding patio door as well as the central mullion on the windows.

What impressed me about Rawington? Technical support before order was excellent, with most emails answered the same evening. Information on delivery arrived without having to ask for it, and I was even sent a picture of the completed windows ready for despatch. Installation was meticulous on a Sunday and Monday, and a return visit offered to carry out adjustments - there will be a few, but nothing major. Window quality and finish is as good if not better than their showroom windows, and upto the standard of the Velux windows. (My job was in manufacture of building products)

Hope this helps the next person looking for windows!

Peter, was there any indication on the windows or packaging to indicate who actually made the windows and what country they were made in ?

The Rawington website does its best to infer that the windows are made in Germany by Gutmann AG.... who errr.. don't actually make windows! They are a systems producer. ie. they sell window systems to fabricators or joinery companies who actually make the windows.
What warranty did you get (not from Gutmann for sure) and was it provided by the manufacturer ?

Monty

Alu-clad wooden window quotes received - help me decide please

Peter65 — Wed, 02 Feb 2011 20:33:57 +0000

Sorry about delay in responding, I locked myself out of the forum.

Windows were made in Vilnius, Lithuania, and Rawington gave me the name of the manufacturer - its one of the large Baltic manufacturers. (I worked for a major multi-national and many of the big name manufacturers supply from the Baltic countries into their home markets in Scandinavia and western Europe, and was reassured by all the supply chain info given me - this arrangement is normal). Warranty is provided by Rawington, 7 years on paint and manufacturing, 30 years rot and fungal decay.

Peter

Alu-clad wooden window quotes received - help me decide please

wookey — Fri, 04 Feb 2011 00:56:40 +0000

Can someone who has lots of windows and door specs to hand give me some idea of expected weights? e.g for 2.0*.9m 2G or 3G fully-glazed door and 1.5*0.7 windows.

Alu-clad wooden window quotes received - help me decide please

cornishben — Fri, 04 Feb 2011 09:25:09 +0000

wookey - we unloaded our GBS EcoContract 3G windows/doors from the lorry by hand yesterday, I can confirm that the 2.7m x 2.1m fold aside doorset is pretty damn heavy! (that was a stressful moment as it teetered on the edge of the lorry above the quivering masses)

Impressions of GBS and the windows - We had great service and support with endless emails finally deciding the spec, a pretty good price and although most of them are still packaged up the one we opened up yesterday evening looks lovely.

Alu-clad wooden window quotes received - help me decide please

fostertom — Fri, 04 Feb 2011 10:53:03 +0000

You can easily work out weight, dominated by density of glass (x area x thickness x no of panes) + a minor bit for the timber frame, or calc that too. Just get the figures to hand and henceforth work it out in seconds.

Alu-clad wooden window quotes received - help me decide please

Monty Gerhardy — Sat, 05 Feb 2011 20:44:29 +0000

Posted By: Peter65Sorry about delay in responding, I locked myself out of the forum.

Windows were made in Vilnius, Lithuania, and Rawington gave me the name of the manufacturer - its one of the large Baltic manufacturers. (I worked for a major multi-national and many of the big name manufacturers supply from the Baltic countries into their home markets in Scandinavia and western Europe, and was reassured by all the supply chain info given me - this arrangement is normal). Warranty is provided by Rawington, 7 years on paint and manufacturing, 30 years rot and fungal decay.

Peter

Lithuania? Fancy that.
Reading the entire Rawington website there are precisely zero mentions of Lithuania. Reading the company profile the casual reader would certainly get the impression that the windows are made in Germany â€“
â€œPartners
Gutmann, with a 69 year history in the aluminium industry, is the biggest privately owned extrusion company in Germany and one of the biggest in Europeâ€
â€œDesign and Development
Presented systems embody the best of German engineering design.â€
â€¦and a picture of the factory inâ€¦Weisenburg, Germany !

No manufacturers warranty ? Thats brave after spending so much money

Caveat emptor would be my advice

Monty

Alu-clad wooden window quotes received - help me decide please

Monty Gerhardy — Sat, 05 Feb 2011 20:48:17 +0000

Posted By: wookeyCan someone who has lots of windows and door specs to hand give me some idea of expected weights? e.g for 2.0*.9m 2G or 3G fully-glazed door and 1.5*0.7 windows.

1sq/m of 4mm glass weighs 10kg.
1sq/m of 6mm glass weighs 15kg.
Standard double glazing is typically two panes of 4mm so weight is 20kg sq/m
Laminated glass is typically 6.4 mm so 40kg sq/m (or 30kg if 4+16+6.4 as often used in Scandinavian doors)
+50% for 3G
Frame as noted above is only a few kg

Monty

Alu-clad wooden window quotes received - help me decide please

tahir — Wed, 09 Mar 2011 15:20:45 +0000

I agree that the Rawington website is misleading. I've also found it almost impossible to get answers from him (I've only ever spoken to a single person there). I think we're going to go with Internorm (Varion), only issue is lack of sliding and folding/sliding doors to 0.8 U value and 2.5 mtr heigh, SolarLux do an AluClad folding/sliding door (SL97) but haven't managed to find a sliding door yet. Adpol said they could but the quote's come back with much higher U values than expected.

Alu-clad wooden window quotes received - help me decide please

tahir — Thu, 10 Mar 2011 10:59:53 +0000

Also, anyone know how much timber choice can affect U value? According to Adpol the difference on their AluClad triple glazed unit is huge:

RED MERANTI: 0,78
PINE OR EUCALYPTUS: 0,82
OAK: 0,92
LARCH: 1,1

Alu-clad wooden window quotes received - help me decide please

Justin — Thu, 10 Mar 2011 12:31:32 +0000

I wanted to understand this before I bought (Adpol softwood as it turned out..).

The frame becomes a bigger proportion of the total as the glass improves, and other things being equal, without thermal broken frame it begins to show up as large variations in the overall.

Alu-clad wooden window quotes received - help me decide please

michaelmaguire — Thu, 18 Oct 2012 22:25:40 +0100

This post was very helpful for us and it was one of the ones that lead us to Adpol. We saw several window providers and got several quotes. In the end, we put our money down (in June 2012) for Adpol. It wasn't the cheapest quote but neither was it the most expensive.

It's October now. I'd like to tell you how the windows are, but we still haven't received them yet. ;-)

I've written about our experiences with Adpol here:

http://my-experiences-with-adpol-windows.blogspot.co.uk/2012/10/why-i-am-creating-this-blog.html

in case it's helpful to others.