Passive window recommendations please

[jack]

15 minutes ago, craig said:

I appreciate that and sorry to hear that happened. We are not all perfect, by a long shot and mistakes do happen. Mistakes can be avoidable though. I bet the supplier, installers didn't look at the details supplied which resulted in the problems encountered?

 

The architect used the supplier's standard details, so neither of them was the problem. Indeed, we took the architect with us when we visited the factory (huzzah for ultra-cheap flights!) and the managing director went through all the details and suggested some useful tweaks, especially around thresholds.

 

The installers were the sole source of the problem. It shouldn't have been like this though, because they were also the official sales rep for Ireland for the supplier (the supplier being a German company located in the Mosel valley - I'm sure you know the company, but I'd rather not identify them given that they weren't the source of the problems). The installers missed an important element in the sections, which involved all windows being packed up by 15mm to allow for the correct fall on the cills. This was drawn and annotated on the details that we supplied to them when they quoted.

 

They also failed to check the installation details for the external blinds, and only discovered after all windows had been installed that the external battens in the reveal prevented attachment of the blind rails.

 

Other than a slightly threatening series of text messages with one tradesman who we ended up having to kick off site, this was by far the most stressful part of the build for us.

 

[jack]

43 minutes ago, Crofter said:

As a minor aside, aesthetically I think windows look much better when set back a bit into the facade. Maybe it's just because that's the norm up here, but when they are flush with the outside surface of the wall it looks a bit cheap, to me.

 

 

We had battens pre-installed within the reveal, positioned so that they stopped the windows in the correct position relative to the insulation.

 

I agree completely about flush windows. In fact, I'm sure that I read somewhere (maybe A Pattern Language?) that externally flush windows are a major factor in modern houses not looking quite "right".

[Stones]

The only issue I had with my windows, was missing the order deadline for getting our windows delivered before the summer factory closedown, and that was down to lines of communication between myself, the builder and the window supplier.  Other than that, it was all peachy.  I provided the list of window sizes for the supplier to quote on, they produced a schedule which I signed off having checked each window to confirm correct size, interior colour, exterior colour, hinge type, inward/outward opening.

 

Made available for collection (as I arranged my own haulage due to remote location) on the date specified after order confirmation.

 

Same supplier used by @ProDave (ADW Ltd)

[Barney12]

4 hours ago, Crofter said:

or aside, aesthetically I think windows look much better when set back a bit into the facade. Maybe it's just because that's the norm up here, but when they are flush with the outside surface of the wall it looks a bit cheap, to me.

 

For us on the Dartmoor National Park having windows set back by at least 100mm is a planning condition. 

I agree with you on flush faced glazing but it can look good in the right designs. 

[Jeremy Harris]

Worth remembering that the window frames MUST be wholly within the insulation layer in order to avoid thermal bridging around the frame, and a potential cold spot and condensation risk.  Window and door frames are already the poorest performing part of a door or window, worse than the glazing as a general rule, so making sure they are surrounded by insulation makes a significant difference to the overall performance, as well as reducing the risk of condensation around the edges of the frames. 

 

This usually means that the frames need to be set back from the outside skin of the house.  We have a relatively thin outside skin (25mm counter battens plus 20mm overlapped waney edge larch) so our windows are set back by around 70mm overall from the furthest edge of the outer skin.  If we had a brick or block skin they would have been set further back.  I compromised a bit on thermal performance, by setting the outside of the frames flush with the outer skin of the insulated twin stud wall, ideally they should have been around 20 to 30mm further in, but setting them flush with the frame skin made the cladding an window reveal detail easier, and overall the thermal penalty seem small; less than 1 deg C temperature difference between the frame and the inside walls in very cold weather, which seems acceptable, and results in a near-zero frame condensation risk.

[TerryE]

Jeremy's first comment is accurate, but IMO there is still a trade-off to be made here. At one extreme bridging could the interpreted has any extra heat loss due to the construction at the interface.  We have an outer stone skin covering an MBC timber frame, and the window sit half inside the frame and half closing the gap between the skin and the timber panelling.  This arrangement definitely has more heat losses then positioning the windows in the middle of the timber frame, but when I do the sums, it works out at only a few W. Yes, the reveals adjacent to the windows will be a few degrees colder, but not sufficient to result in a risk of condensation.

 

The benefit of this arrangement is the improved external aesthetics, and the far better construction of the interface between the stone and the windows means that there is for less risk of weather compromise between the frame and the outer skin.

[Alexphd1]

since i have been rained off site this afternoon I have finally managed a couple of hours to sit down and wade through the 3g glazing quotes. Just wondering if anyone has came across polish interiors, they seem to be ticking the boxes? My icf supplier speaks highly of them.

[Plumbersmateuk]

I made reference to Polish windows in another topic.

This may be of Interest if not stumbled across before

http://www.windownews.co.uk/benefits-of-importing-windows-from-poland/

 

https://www.aikondistribution.com/

[gravelld]

22 hours ago, Alexphd1 said:

since i have been rained off site this afternoon I have finally managed a couple of hours to sit down and wade through the 3g glazing quotes. Just wondering if anyone has came across polish interiors, they seem to be ticking the boxes? My icf supplier speaks highly of them.

 

They are fairly well known, they work the UK exhibitions if you want to pop and see them.

[graeme m]

On 02/08/2017 at 10:48, Declan52 said:

Don't get to hung up on the fact your Windows have to be up to passiv standard unless you are going for the full on certified route. You can quite easily blow a massive hole in your budget with Windows and leave you skimping else where. Set yourself a budget and stick to it. Even 2g Windows now are of a pretty high standard.

Not much point in having passiv standard Windows and the rest of the house just meeting building regs.

 

We are going full certified.

 

[graeme m]

So far only Ideal Combi have quoted and they're not passive certified. Has anyone achieved Passive Cert with windows that have passive figures but no cert?

 

[PeterW]

I may be wrong @graeme m but I thought that using a "certified" product just short circuited part of the process as you didn't need to produce the paperwork to support the product specification..?

 

@craig may be able to advise  as that's his area of expertise. 

[craig]

Yes, we have numerous projects with non certified windows. You'll find a lot of suppliers will use the non certified product. For Instance, Internorm tend not to use the certified product because the certified product costs about 25% more (at least that used to be the case, I would need to double check if they have had any of the standard systems certified).

 

Certification is a marketing tool, it does also make the certification process a little easier but only just. You don't need and are not required to use any certified product on a Passive build.

 

You just need to prove the product you are using, does what is claimed. You do this by 3rd party certifications, which the supplier should be able to supply. They will generally be supplied with thermal calcs as well.

 

Its important that these values are available at a very early stage, so that these can be entered into the PHPP. If not available, the certifier will generally use standard values advised by the supplier/manufacturer and apply a penalty until the values/certificates are available.

 

I would also say that the shell of any build is not one to skimp on, the shell is what brings the savings. The bells and whistles are things which can be added/tweaked further down the years if need be. Difficult/costly to alter the shell later - I personally wouldn't advise skimping on windows but I'm biased in that view.

Edited August 13, 2017 by craig

[graeme m]

Thanks chaps

 

[graeme m]

I'm gob smacked at the difference in quotes from Rational to Internom £10k difference.

 

[IanR]

7 minutes ago, graeme m said:

I'm gob smacked at the difference in quotes from Rational to Internom £10k difference.

 

 

Is that like-for-like? Approx how much per m2 and for which product?

 

I know my experience was not the norm, but Internorm were slightly cheaper for me like-for-like (although I ended up spending slightly more on a higher spec Internorm and a "PH" install that the Rationel supplier didn't offer.)

 

I believe a lot comes down to the supplier you use. My local Rationel supplier was not interested in negotiating any significant discount, but rather tried to push another brand "if I wanted to save money", Where as the Internorm Supplier I used seam to have much better discounts from Internorm than the other Internorm suppliers I approached.

[graeme m]

No, they aren't identical and Internom include £6000 for fitting and the spec is different, £6000 different I don't think so?

[craig]

It comes down to numerous factors and is hard to tell without seeing the quotes.

 

However, Internorm are a high end Austrian product and a lot of differences exist between the two. With Internorm, it also depends on which retailer you have had a quote from. Prices vary between retailers.

 

Look at the supply price excluding fitting, is it comparable or £4K / £10k different - possible the end figure including installation may have been used when comparing figures?

[ProDave]

12 hours ago, graeme m said:

I'm gob smacked at the difference in quotes from Rational to Internom £10k difference.

 

Which way round?

 

I found internorm twice the price of Rationel, and only very slightly better Uw values, but others have found internorm cheaper.  I am not sure from your statement which was the cheapest in your case?

 

It is staggering how the quotes we get can vary so much.

[dogman]

13 hours ago, graeme m said:

quotes from Rational to Internom £10k difference.

Check the rational quote as they don't normally include sills it added 1000+ to our Rational quote and another 7500 for fitting. However i now wish we had used them 

[IanR]

You've got to strip out the differences between the quotes to be able to compare.

 

Even the small stuff like Internorm deliveries turning up with Installers and 100% handled by the Installer compared with what we were offered by Rationel which was us taking delivery and storing at our risk until the installer turned up a few days later, adds value to the Internorm quote.

[graeme m]

Rational were the cheaper. Did anyone look at Origin?

 

[JamesP]

Rained off today on Dartmoor so time for some window shopping. Internorm / Rationel have both quoted for triple glazed, tilt and turn and prices are near identical.

Can any owners of the above offer any practical advice regarding opening types especially tilt and turn.

Thanks all.

@Stones @JanetE

@Barney12@IanR @dogman @ProDave @craig

[ProDave]

We chose top hung, so they only open outwards. You can open them all the way so the inside faces out, and the outside in, so you can clean the upstairs windows from inside.

 

As I understand it, tilt / turn open inwards. Not the best idea when you have left a window open and a rain shower comes by?

 

In the previous house we chose side hung, as that's what we had always had, and the idea of top hung to us back then just sounded odd, but now I would not choose anything else other than top hung.

 

Again @JamesP Interesting how the prices vary so much.  The quote we had, Internorm had a very slightly better Uw value than Rationel so if the prices are near identical that might sway it for Internorm?

[craig]

I personally prefer tilt & turn over outward opening windows, top hung, reversible etc. shop around and check the quotes are on par with each other. Check installation, aluminium cills and so forth are included.