Will my windows be a problem to source/expensive

[AliG]

Hi,

 

I have attached the elevations of my parents' house.

 

The architect has created a very modern design as asked, which has a lot of glass. There is 72sq metres of glass plus two doors for a 195sq metre house which is a pretty high ratio.

 

The plan is to have alu clad 3G windows.

 

As drawn on the elevations, the largest windows are fixed panes 2.63x2.39m, I suspect this is too large but there is room to change this. All the downstairs windows are 2.63m tall.

 

There is one set of sliders 3.64x2.63 for the kitchen.

 

We have Rationel windows that we are very pleased with on our house, but the maximum height sliders they can make are 2.388m.

 

I have also noted that if we want any of the downstairs windows to open, Rationel cannot make them.

 

I would like to use Rationel as we are using an MBC frame and they can supply and fit Rationel. I thought the price was reasonable for the quality on my current house,

Would it make sense to mix Internorm/Solarlux sliders with Rationel or will Internorm not be as expensive as I am worried about?

 

Has anyone had MBC provide Rationel, was the price reasonable and was it worth it to get everything from them or should I not worry about getting the windows elsewhere?

 

I checked out various suppliers, Idealcombi can go to 2.6m high on sliders, Nordan 2.588 and Velfax 2.475. The architect was very against reducing the window height, but it does seem to me that reducing it by 50mm would maybe give us a lot more options. I think the Rationel max height is too big a change.

 

Also does anyone have access to the maximum sizes for different kinds of Internorm windows, I have struggled to find this.

 

Maybe my best option is to get a window schedule drawn up now before the frame is signed off and get quotes.

 

By expensive I mean much more than £350 a sq metre ex vat and fitting.

 

Thanks

 

 

Elevations.pdf

Edited August 17, 2020 by AliG

[craig]

45 minutes ago, AliG said:

Maybe my best option is to get a window schedule drawn up now before the frame is signed off and get quotes.

 

It should always be a priority, not having one leaves quotes open to interpretation/imagination of the suppliers at the quoting stage. Your architect hasn't indicated any handling of windows on the elevation drawings for example.

 

45 minutes ago, AliG said:

the largest windows are fixed panes 2.63x2.39m, I suspect this is too large

 

That's not that overly large but the width/height ratio would need to be checked, max glass size for laminated pane/toughened pane also accessibility to site and on site. How will they be manouvered? Things like that will determine whether being supplied in one unit or coupled is more feasible. 

 

45 minutes ago, AliG said:

Also does anyone have access to the maximum sizes for different kinds of Internorm windows, I have struggled to find this.

 

Generally speaking, 3m height is fine (width dependant), they and others will be able to do 4m height (width dependant).

Edited August 17, 2020 by craig

[Pm1987]

Have you contemplated breaking opening up into smaller window ?  Our openings are approx 2.5m x 2m.

 

 

[ToughButterCup]

11 hours ago, AliG said:

...

There is one set of sliders 3.64x2.63 for the kitchen

...

 

How much?

Here's what my roughly equivalent (bit bigger , but not much)  window cost - triple glazed. Every single person who has seen it plays with it - weighs a ton, move it with one finger. 

 

In the context of comparing quotations, I found it really difficult to compare like with like. For me, detail contained within the the quote matters. Some producers were - to our mind - light on detail, and so were filtered out quickly.

Edited August 18, 2020 by ToughButterCup

[Thorfun]

and as another comparison, here's our largest slider quote from Norrsken. and I agree with @ToughButterCup in that comparing quotes was hard. I found that Norrsken were very upfront and contained a lot of detail in their quotes and included everything I could possibly need in the quote. so there were no hidden extras. 

 

 

although they don't do UPVC so will probably not be what you're after. but they were able to do the following window with no size issues. (3.3m high at the apex)

 

 

(all posted with the caveat that I haven't started building yet so my opinion could all change once we get to the delivery and installation stage)

 

 

[Bitpipe]

13 hours ago, AliG said:

The architect was very against reducing the window height, but it does seem to me that reducing it by 50mm would maybe give us a lot more options.

 

That's nice but they don't need to source them, pay for them or install them  

 

You pay them to do what you want, so go do your research and if a tweak to the design  makes your life easier then just get them to do it.

 

Supply and fit as a package is the only way to go - numerous advantages namely there is zero VAT applied (vs you paying VAT and then reclaiming later), supplier is also responsible for the windows on site until they're installed.

 

Make sure there is no ambiguity over what handling equipment is required and provided either as part of the quote or by you - no good a team of installers arriving and expecting a tele handler that's not there.

 

Have you/architect done a draft SAP calc to see how that amount of glazing impacts the house performance?

 

Have you/architect calculated overheating risk (extends from spring to autumn, not just summer) and designed in provision to minimise (external blinds, bris Soleil, recessed frames, solar film etc)?

 

As a happy owner of a MBC house with Gaulhofer windows (including two 4.5m x 2.2m sliders, fingertip operated) they are unforgiving when the sun is shining through them. We specced external electric blinds for the east elevation and use internal drapes to reduce west sun in the evening (plus external blinds on the Velux roof windows).

[AliG]

Thanks for the comments. The main issue is with the height of the sliders, if they were a more standard 2.2m high I would not be so concerned as I could get them from Rationel or many other places, but from the companies I have been able to find a maximum height on a sliding door for, only Internorm can supply a slider this tall. I have checked Rationel, Velfac, Nordan, Ideal Combi and Internorm but not Gaulhofer or Norrsken. Someone did post quotes on a similr sized window from Internorm and it was more like £9k.

 

Breaking up the windows might be necessary. For the two large fixed panes, again from the companies that I could find that produce data on maximum window sizes you start to run into trouble when a single element is above 5sq metres. So if the windows were 1.5m wide x 2.63m tall it would be OK, I have some windows around that size, but over 6 sq metres is outwith the normal scope for many companies often they run into a maximum weight limit. Similarly opening windows are often limited to around 1.8m in height, so after that they would need to be either fixed windows or broken up.

 

I have run the heat loss calculation using JS Harris spreadsheet. the large amount of glass does increase the heating requirement, but not enormously so. The windows will account for half the heat loss for the whole house. It still only comes out as probably requiring around 9000kWh of heating a year which is very low.

 

I have been thinking about overheating on the lounge and kitchen windows but have not made a decision yet. We will probably have the ASHP rigged to be able to run in cooling mode, and might consider internal blinds or a heat reflecting film/tint.

[craig]

 

2 hours ago, AliG said:

I have checked Rationel, Velfac, Nordan, Ideal Combi and Internorm but not Gaulhofer or Norrsken

 

You should. Your 2.63x2.39 fixed window, will be under 300KG triple glazed. It generally should only start to cause concern at 400KG.

 

I have previously declared myself in introductions but only here to help and offer advice and don't like to see someone stuck or think they are limited in choices. The sizes you have mentioned are not restricted to just Internorm, generally speaking some suppliers will struggle with the sizes due to a number of factors. One of them being engineered timber v's non engineered timber and overall unit weight. Numerous suppliers/manufacturers will be able to meet those sizes easily & the price for the slider should be nowhere near £9k for that size if I'm honest, probably more like £6K/£7K possibly less dependant on system.

 

Tilt and turn at 3m high should also not be an issue but again you need to take in the width/height ratio of the opening section.

Edited August 18, 2020 by craig

[Dan F]

2 hours ago, AliG said:

I have been thinking about overheating on the lounge and kitchen windows but have not made a decision yet. We will probably have the ASHP rigged to be able to run in cooling mode, and might consider internal blinds or a heat reflecting film/tint.

 

Not considered external blinds?

[Thorfun]

1 hour ago, Dan F said:

 

Not considered external blinds?

+1

[AliG]

Sorry, yes it was not an exhaustive list

[ToughButterCup]

4 hours ago, AliG said:

...

I have been thinking about overheating on the lounge and kitchen windows but have not made a decision yet. We will probably have the ASHP rigged to be able to run in cooling mode, and might consider internal blinds or a heat reflecting film/tint.

Forgot to mention that our window has a large set (4m high) of external louvres for precisely the reason you give.

Together they make  a very pleasant combination in terms of light,  shade and " air ". 

Wot that Kevin off Ch 4 calls a Breeze Corridor 

 

 

[SuperJohnG]

It funny the different sizes different suppliers cam cope with. I have a 4.6m opening and decided I want a two section slider (one pane fixed) 

 

Express were able to do it,.but rational can only get up to 4m wide which is a pain as they are a decent price but I feel like 600mm is a lot to lose. Waiting on Nordan coming back and sent something to Gaulhoffer but not heard back @craig who is the Scottish dealer? Is that you guys?

 

Id never heard of norssken until now, thanks @Thorfun

[Thorfun]

2 minutes ago, SuperJohnG said:

Id never heard of norssken until now, thanks @Thorfun

I first heard of them from members on here. @vivienz and @Russell griffiths are a couple that come to mind that both had Norrsken windows and had good things to say about them iirc. so the thanks should go to them! ? 

[Pete]

21 minutes ago, Thorfun said:

I first heard of them from members on here. @vivienz and @Russell griffiths are a couple that come to mind that both had Norrsken windows and had good things to say about them iirc. so the thanks should go to them! ? 

We liked Norsken but they could not do the size of sliders we required. We liked the built in insect screen that was hidden in the frame that you just pulled across when the the door was open

[Thorfun]

8 minutes ago, Pete said:

We liked the built in insect screen that was hidden in the frame that you just pulled across when the the door was open

 

cor....not heard of this with Norrsken! will need to speak to our sales guy as he never mentioned it. just goes to show that they don't do the hard sell I guess.

[craig]

46 minutes ago, SuperJohnG said:

Gaulhoffer but not heard back @craig who is the Scottish dealer? Is that you guys?

It is, sent PM. Apologies but only myself working and inundated with quoting and Other work. 
 

Way behind but we’re back up in strength next week and back to the office as well.

[AliG]

@craig

 

Thanks for your helpful input.

 

As is typical of architects, he didn't really seem to have considered where we might get the windows until I started to look around.

 

We were planning to have a window schedule, I was just thinking is there time to send one out to some people before we sign off on the frame in case we need to make changes. Originally the plan was to do it afterwards.

 

I like to try and do my own homework on things before contacting companies and the limits on window sizes are available from some and not others. It just happens that we have Rationel on our house, but they seem quite limited size wise for sliders and opening windows. They have a limit of 2398 on tilt and turn and 1798 on side hung/guided which made me worry that if we wanted a few of the downstairs windows to open we might have a problem. It might just be though that they have lower limits than some other people.

 

As it seems Gaulhofer might have the sizes we want available, and you guys are reasonably local, which I like, I might be in contact once I have spoken to all the people involved.

 

[SuperJohnG]

9 minutes ago, craig said:

It is, sent PM. Apologies but only myself working and inundated with quoting and Other work. 
 

Way behind but we’re back up in strength next week and back to the office as well.

Granted. Its only been yesterday since I sent request. I'll keep an eye out.