We have now received all but one of our window quotes. As we are already behind schedule and most of these suppliers have an 8-10 week lead time to delivery I need to decide on the supplier asap and order by the end of the week if poss. Any help or advice, any supplier to be avoided or recommended - all information is very welcome, I really need help on this.

Quoted for:

2 windows 1400mm wide by 2100mm high (one section of 700mm fixed, one tilt and turn), 1 external door 800mm by 2100mm, patio doors 2800mm wide by 2100mm high (four sections of 700mm each, inner two as french doors, outer two fixed), two tilt and turn windows 800mm wide by 1600mm high

Specification: aluminium clad wooden double glazed window, RAL colour on alu outside, wood stain on inside; U-values as low as poss but not Passiv House standard

Quotes received:

Adpol (windows from Poland): £7727 inc VAT&Deliv; 8-9 weeks

ecomerchant (windows from Germany): £6861 inc VAT&Deliv; 4-5 weeks

Internorm (windows from Austria): £8684 inc VAT&Deliv, inc installation; 8-9 weeks

Nordan (windows from Norway): still waiting; 8-10 weeks

Rawington (windows from Germany): £8058 inc VAT&Deliv, inc installation; 8-9 weeks

Russell Timbertechnology (windows from Glasgow): £7737 inc VAT&Deliv; 7-8 weeks


I would like to chose ecomerchant, obviously due to the price but also because of the short lead time but their windows have the highest U-value of 1.54-1.56 for the whole window. Is that as high as it seems or is this quite good? In comparison, Internorm claims a U-value of 1.1 for the whole window.

Has anybody used their windows? Would you recommend them? Is it worth waiting for Nordan? Is the aluminium cladding pointless and should I just opt for wood alone?

I would appreciate any input on this as I have only ever bought PVC windows and no experience with wooden windows. Thanks in advance,

Maren

We are going with Rawington for oak framed, alu clad windows, french doors and a folding-sliding door set with level threshold. They have been very helpful and patient with us whilst we've worked out what was needed for our home, including a window sample in the right colours for planning consent. Our order is in and we're currently waiting on a delivery date.

Some of our decision came from the quality of the mechanism with the Rawington windows - some of the others we looked at had excellent frames and glazing, but were let down with very basic ironmongery. The Rawington ones have the standard tilt/turn action, but also a position that pulls the whole window a fraction away from the frame to give a trickle vent effect around the perimeter. We're happy to go with the European style inward opening window, I'm not sure if other suppliers give you an open out option.

Unfortunately for you, it'll be a month or so before we can give you feedback on the quality of the installed product.

V interesting.

Forget NorDan - they've declared themselves not interested in the small domestic market - but don't bother to tell you so.

The prices look OK - from £373 to £472/m2 ex VAT.

Generally aluclad seem to be 15-20% up on the all-timber equivalent - except in the interesting case of Russell, whose Al design is more like an aluminium window with inner timber cladding, consequently 60% up on their all-timber equivalent. Currently Russell's all-timber price is vastly better than anyone elses - recently £250/m2. If you can accept all-timber, with long-life high-build opaque/colour 'stain' factory finish, Russell's are the bargain of the 21st century currently.

The whole-window U-values you quote are terrible - you understand that higher number is worse? I hope you're skipping double glazed and going straight to triple, which in this league costs little if any extra. You should get 1.0 or 1.1 Uw (whole window u-value), with 0.6 Ug (glass centre-pane U-value). Or down to 0.6-0.7Uw with Passivhaus-standard inward-opening, but you'll pay more for that.

Posted By: Maren
Is the finish on the Russell all-timber fairly maintenance free? How long till I have to paint them?

As much as any of that spec - they'll advise.

Posted By: MarenHow is the ironmongery?

Not Rolls Royce but adequate (true of the whole window) - not the open-a-crack secure feature unfortunately.

Posted By: MarenHave you seen those windows?

Specd succesfully on 2 quality projects - 3rd in the pipeline.

Posted By: MarenHow do they compare to the Internorm

Internorm supposed to be v gd - if you can stand the rather ornate 'styling'. Internorm I thought go straight for Passivhaus standard - so it's odd that they quote only 1.1 Uw.

Russell don't seem to be just the offshoot of some european manufacturer. Their stuff when it arrives is labelled from all over the far reaches of N/central/E europe, so maybe their secret is wide sourcing. Perhaps because of this, delivery times a bit unreliable - but worth the wait!

Thanks valasay for the heads up on the maintenance - I am very undecided now regarding the aluminium cladding as it does add 10 to 20% to the cost for most suppliers (but see fostertom re Russell = 60% above) plus an extra 5% because we asked for white outside and woodstain inside. Although we are not in an exposed location so wear and tear should be normal, planning has determined that all finishes have to be matched to existing and our PVC windows are white, so I would have to keep repainting them later on, while the aluminium is supposed to be maintenance free.

fostertom - have now spoken again to Russell, all-timber are maintenance free for 5 years if looked after, meaning keep them clean and patched up so small blemishes don't turn into bigger ones. That does not sound like 5 years maintenance free to me but maybe that is normal for wooden windows.

Internorm is 1.1 for double glazed windows, Russell 1.4 for double and 1.1 for triple, Nordan 1.4 for double and 1.0 for their (second choice) triple glazed windows

Posted By: fostertomInternorm supposed to be v gd - if you can stand the rather ornate 'styling'. Internorm I thought go straight for Passivhaus standard - so it's odd that they quote only 1.1 Uw.

Internorm do whole range from double glazed to passivhaus certified (I am interested in the latter). As such, they do supply windows with higher u-values. I don't think they offer a frame with thermal breaks. If I recall correctly even their passivhaus frames weren't thermally broken which I thought was surprising at the time.

I agree that 1.1 seems very good for a double glazed window - some triple glazed aren't that good. I wonder if Internorm are really quoting for a triple glazed panel?

I would generally support investigating triple glazed. Many have reported that the cost differential is now small, so it's worth looking at even if you reject the idea.

Yeah small windows are a temporary blind alley (unless part of an old house) resulting in strange-logic decisions (sacrifice insulation because starved of daylight). Unless a window is located such that it actually receives much solar heat during the heating season, plus the building is arranged to store and usefully retrieve that heat, then a window is nothing but a winter heat-loser and a summer over-heater, so should have lowest possible U-value, whether it's in the sunny south or the top of Ben Nevis.

Posted By: TunaOn the triple glazing front, we decided against based on two factors:

1. The additional glazing has a noticable effect on interior light.
2. As the rest of our house has high thermal spec, and the glazing area is unfashionably small, the benefit of moving to 3G is really pretty minimal. I remain unconvinced that 3G is worth it at least in the mild climate of the South of England.

Money better spent elsewhere perhaps?

That may be true in your case, but certainly wasn't for the original poster. Those windows were pretty big by any standard.

In your case, I'd argue that if you've gone to the trouble of insulating the rest of the fabric well then it seems a shame not to fit matching performance glazing. Of course, if the windows really are so small that the small degradation in light throughput for 3G is so significant then I can understand the compromise.

Is 3G really 20% more than 2G?

Posted By: fostertomYeah small windows are a temporary blind alley (unless part of an old house) resulting in strange-logic decisions (sacrifice insulation because starved of daylight). Unless a window is located such that it actually receives much solar heat during the heating season, plus the building is arranged to store and usefully retrieve that heat, then a window is nothing but a winter heat-loser and a summer over-heater, so should have lowest possible U-value, whether it's in the sunny south or the top of Ben Nevis.

I don't quite follow your logic - our windows aren't tiny, but they're not in the modern grand designs style that seems to cover entire walls. For a ~180 sqm house, we have 20 sqm glazing. How does being starved of daylight result in sacrificing daylight? The argument for maximising solar gain makes a lot of sense, but not all sites can be positioned to do so. In our case we're east/west facing.

My point was that with relatively modest area, the difference between good 2G (say 1.3 W/m2/K) and 3G (say 0.8 W/m2/K) amounts to 10W/K or around 100Watts additional heat loss for a 10 degree difference in temperature. Ignoring the reduction in solar gain (which would only further reduce the difference), that's not a lot. When you're fighting the budget, you find yourself picking your fights.

We never managed to find 3G that came in at similar prices to 2G, unless we lowered the spec of the frame. As inexperienced self-builders though, we probably aren't knowledgable enough of the market to find the bargains.

Posted By: Tunaour windows aren't tiny

I got that impression - if bigger isn't daylight adequate even if reduced by 3G?

Posted By: TunaHow does being starved of daylight result in sacrificing daylight?

I said 'sacrificing insulation'

Posted By: TunaThe argument for maximising solar gain makes a lot of sense, but not all sites can be positioned to do so. In our case we're east/west facing

If solar gain is possible (during the heating season) and you're set up to take advantage of it, then those windows may need to be 2G, to maximise gain, as 3D reduces gain (as well as daylight). Windows not 'doing' gain shd be 3G, unless too expensive! E/W facing facades can be v gd for heating season gain, as sun penetrates deeply at low elevation, better than south facade/higher elevation.

Posted By: Tunanever managed to find 3G that came in at similar prices to 2G

if that's so, then yes maybe not worth it.

Nothing wrong with the solar gain available during the UK heating season. It'll be compulsory to housebuilders to rely almost entirely on it for heating, by 2016 (2013 in Wales, 2011 in Eire).

Don't think there's an instant answer to the question - it has to be thermal-modelled for the individual set-uo, either by the PHPP Passihaus procedure (the UK SAP lookalike isn't up to it, until forthcoming revision hopefully) or by computer thermal simulation by Tas, EIS, Hot3000 etc. Or by seat-of-pants! Any better ideas, anyone?

Update on Nordan: £7037 inc VAT&Del with French doors, £7560 inc VAT&Del with tilt and slide patio doors;
quoted for double glazed alu-clad windows and doors (U-value at 1.4 for the whole window)

fostertom: you might well be right but when you have a house like ours that has absolutely NO insulation whatsoever, my extension budget has to be smaller to allow for insulating the rest of the house and to fit better windows and doors there.

What would you do - spend all you have trying for a zero-fuel extension and let the old part of the house bleed heat away (and it is absolutely shocking how little heat the house holds) or compromise on the new build in order to improve the old part as well? Btw I have been advised that insulating the extension too much would be bad for air-flow and adversely affect the old part of the house - I didn't believe it but what do you think?

jezza22: Velvac does not seem to provide tilt and turn windows and for "Rational" do you mean "Rationel"? Rational yielded only German kitchens, albeit good ones, Rationel, however, is a window and door supplier.

Maren I sympathise with your dilemma - too much that's worth doing, for the money available. No half measures tho - if insulating do it really well or leave it till later - you'd only have to re-do it. Take in the message of my info sheet - energy saving measures can be readily seen as zero- or negative-cost, if they create cost savings or capital value increases over a period of your choosing - you still have to finance that period of course. Research and take a view on future fuel prices and consequent capital value effect, then do your calcs and act accordingly, even if against the conventional wisdom. It's scary! But good to get all that very clear, even if you can't act on it just now.

Posted By: Mareninsulating the extension too much would be bad for air-flow and adversely affect the old part of the house

Depends how it's done. Most arguments in favour of uncontrolled leakiness are misguided.

Posted By: fostertom It'll be compulsory to housebuilders to rely almost entirely on it for heating, by 2016 (2013 in Wales, 2011 in Eire).

With my cynics hat on, I'd say that these requirements will either be scaled back or dropped entirely by then. It doesn't seem to me that the industry is moving fast enough to achieve the goals laid out. Having seen such government initiatives in other areas (and being bitten by them), the usual pattern is that the gov. announce some legislative deadline, a few enterprising companies move heaven and earth to meet the challenge, but the vast majority do nothing. When the deadline is coming up a review takes place and, realising that the goals will not be met, the rules are either relaxed to virtual non-existance or dropped entirely.

Not that that's a reason not to aim for them, but it's probably not a good idea to rely on legislation to improve the current standards to the levels we'd like to see.