I'll check again in the morning.

Posted By: fostertomGreat Johann, I've just asked Inwido to quote that alternative, provided it's available all-timber not Al clad.

You're welcome, they do both timber and Al clad on all their Windows.

Posted By: biffvernonBecause the U-value only falls a little bit and there may be better places to spend your money. Law of diminishing returns

Not necessary true. I bought some windows from Sweden a few years ago. Asked at the time if they'd do me 2G windows. The answer I got was "Sure, we can do that. Will cost you a bit more though." Basically boils down to that 3G is standard, and as always if you want something custom it's more expensive... I'ts worth noting that the 3G timber units I got was not more expensive then 2G uPVC windows would''ve been! And that included £300 for the shipping!!

The beer is pants! It's a lager country...

The women are nice though!

Just saw this on http://www.buildinggreen.com/elists/furnacefree.cfm:
"Be sure to use krypton, which insulates twice as well as air, not argon, which is only 1/3 better than air and has a wider optimal gap. Extra cost is zero to negligible, because you use not 99.999% lab-grade krypton but only first-distillate-stage Kr (around 60-70% Kr, rest Ar, indistinguishable thermal performance -- same Kr as goes in those lousy "watt-saver" fluorescent tubes". This is USA - Krypton's much more expensive here? What is the optimal gap for Krypton? and for Argon? - is that different from the 16mm for air?

Nearly ready to report my survey of UK 3G Scandinavian-style window prices. In the end, only 5, maybe 6 cos could do it - 2 Scandinavian, maybe 1 German imports, 3 UK cos! One of the UK ones is best-price, tho' now they're talking of getting their Scandinavian sister co to manuf this particular order. One of the other UK cos adapted their 2G design to 3G specially at my request, but regrettably are way out on price. There's also the likes of Velfac, which is a different kind of design. Several of the vast majority of European cos who can still only offer 2G, are skipping this type of 4-12-4-12-4 3G design and going straight to 4-16-4-16-4 Passivhaus-spec type, with layers of cork laminated into the chunkier sections, as they've reached the point where the glass has better insulation that a solid wood frame.

Sorry - colon now cleansed http://www.buildinggreen.com/elists/furnacefree.cfm

Triple glazed soft-coat Scandinavian-style timber windows being quoted at £300-330/m2 delivered, presumably less for a whole office block. The cost of triple over double is so small as to make it a no-brainer - but the choice of UK suppliers whose rebates are deep enough for 4-12-4-12-4 units is few:

Russell Doortech, manuf'd in Glasgow or by Norwegian associate, 0141 958 0444 (whose quote I have recently accepted)
Tanums (import) 0115 9321013
SP (import) 01347 825610
The above three are in that price range; the following are more:
Sashless, manuf'd in Yorks to a design developed at my request 01609 780202
Green Building Store, manuf'd in Yorks, the eco bees knees but very expensive 01484 653765

The absence of several household names, who can still only do double glazing, is striking , incl. Rationel (import), Eco Merchant (Vrogum import), Scandinavian Window Systems (various import), and giant empire Inwido who have swallowed the once-excellent Swedhouse. That the majority of suppliers included are UK manufacturers in also surprising - Howarth, of Air-Supply Window fame, have a design under development too. A few other companies blew the invitation to quote in one way or another, so there may be others.

Other companies e.g. Vrogum and Inwido do even higher-spec 3G windows with 4-16-4-16-4 glass and frames timber/cork laminated frames, for European-market Passivhaus etc use. And there's Canadian sources, esp. interesting glass-fibre framed - Paul in Montreal has the info.

There are other ways of doing triple glazing e.g. Velfac's aluminium outer/timber inner stuff, which can also be made up into slim-sightline facade frame assemblies.

Any other names, johan?

Rembrand/Traryd said they couldn't do 3G. The cheapest by a significant bit was Russell in Glasgow, 6 to 8wks delivery (from Norway, in case of my present job). I look forward to seeing their product, in use.

The complacency of so many firms was frightening - all the conventional wisdom of '3G not needed in UK climate', the 2 favourite myths I've just noted in http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1015&page=1#Item_12 etc.
Just received a proud press release - the merging into The Performance Window Group of just two such cos that I contacted, who both have Scandinavian-style 2G products easily capable of modification to deep-rebate 3G, but have no such intention - Mumford & Wood and Clearwood (of Cornwall) - to focus on 'core activities of property development and housebuilding'. God save us from the wisdom of the mass market! Also another Cornish co, recently revitalised by a Polish eco-entrepreneur - they're making 'UK market high performance windows' in Poland, and in so doing have baffled the Poles by ignoring their expertise in super open-in windows, in favour of dreadful skinny 'stormproof' 2G designs. Yuk.

Posted By: fostertomRembrand/Traryd said they couldn't do 3G. The cheapest by a significant bit was Russell in Glasgow, 68wks delivery (from Norway, in case of my present job). I look forward to seeing their product, in use.

I'm confused now. Rembrandt advertise them as triple glazed units, see here http://www.rembrandtimber.com/product_range/windows/timber/timber_range.php.

If they are selling the standard range (as it appears) it would be 3G. I don't think Traryd do 2G windows except on special reqest.

Anyway, I haven't spoken to Rembrandt so I don't know what they told you. Traryd do export abroad themselves so I just called them directly.

another Cornish co, recently revitalised by a Polish eco-entrepreneur - they're making 'UK market high performance windows' in Poland, and in so doing have baffled the Poles by ignoring their expertise in super open-in windows, in favour of dreadful skinny 'stormproof' 2G designs. Yuk.

I have seen those as well, seems the 'stoormproof' look is sold as being better performace in the UK? I find this very puzzling.

Tom, I 100% agree with you on cost vs. performance. It's a no brainer really, very small (if any!) extra cost for a better window. Last time I bought windows directly from one of the Swedish manufacturers I asked if they would do a 2G unit. The answer I got was 'Sure, we can do that. It'll cost you a bit extra though'. Alas, the 3G unit was cheaper the a 2G unit!!

The Rembrand website seems to claim a centre pane U-value of 1.5, is that not a touch high for 3g...?

J

I am surpised you haven't looked at Internorm, the Austrian window company who make a PassivHaus standard window, and who have recently set up offices in the UK. Thomas Frolich is your man.

http://www.internorm.co.uk

How about 3G roof windows - opening and fixed (ie akin to Velux) - does anyone know of a manufacturer?

I need to significantly lighten a north facing and consequently rather dark extension to the back of my recently acquired house and these would seem to be the best route. My concern is that, since roof insulation should be much thicker than, say, wall insulation, the same should apply to a roof window and the best possible U-values should be aimed for. Are there obvious reasons for not going for 3G?

Johan, I'm puzzled, must check again when I have time - but I invited both both Rembrand/Traryd and Nor-Dan to quote for 4-12-4-12-4 3G windows and both said the couldn't; Rembrand/Traryd after special discussions with the factory. Both could I'm sure (reluctantly, and rightly - pointless) offer 4-6-4-6-4 3G if someone insisted. As I say, the latter would be pointless with no gas or with cheap Argon fill, but would work better than any 2G if expensively Krypton filled, as 6mm is in fact the optimum for Krypton - I think that's right - anyone confirm?

Posted By: AdsHow about 3G roof windows - opening and fixed (ie akin to Velux) - does anyone know of a manufacturer?

I don't know of any - big shame. Veluxes are so excellent in every other way, it's a pity they're so stubbornly backward with their glass. If 2G is inadequate for a window, it's doubly so for a skylight, as it suffers a much lower effective external temp than a window - all that radiating direct to the cold night sky. Strange, when their sister co. Velfac (Al-faced timber windows) do offer full 3G, albeit only in the small print.

Posted By: Mark BrinkleyInternorm, the Austrian window company who make a PassivHaus standard window, and who have recently set up offices in the UK

Thanks for that Mark, except the site's completely kaput right now - I haven't looked into Passivhaus-standard windows yet, but they're coming in. I guess that many of the Europeans will skip the 4-12-4-12-4 3G stage, which is just adapted from classic Scandinavian 4-16-4 2G practice - and go straight for the Passivhaus stuff. That's what I advised the two UK manufs who are presently setting up to do 3G. Interesting that Internorm seem to go the Al-faced timber route - they must have a massive thermal break in there somewhere - but looks like an alternative to Velfac - just what I'm after right now.

Nordan's window is called N-tech, try www.Nordan.com, particularly good for those of us that speak Norwegian.... (ie not me)

J

0.5 sounds way too low to me -- like not possible!