Should I build my own windows?

[MattD]

I'm designing a new build to the latest regs. A neighbour recently had new glazing fitted to their entire house and the company that supplied them mis-measured everything by ~5mm (they were fitting new glazing in existing frames). The company turned up with the incorrect sized glass and they got to keep it. They have offered me all of the incorrectly sized glazing (Pilkington K) for free.

 

Many of these donated glazing units would be quite close to what we need, so I'm minded to take up this offer and get custom-made window frames to fit the glass. There will be a slight deviation from original window sizes, but we need to put in a planning amendment to adjust other aspects of the windows so this is all changeable. We're required to use wooden window frames.

 

The way I see it, I have three options:

• Self-build the window frames to fit the glass
• Commision custom-made window frames to fit the glass
• Ignore this offer and just buy off-the-shelf windows in standard sizes

 

I read here that the price of off-the-shelf windows is now roughly the same as custom-made windows. Assuming that's true(?), then it would make sense to make use of this glass, as presumably it will bring the build cost down. I appreciate that the major part of a window cost is the frame, but I presume this would at least make enough of a difference to be worthwhile.

 

That leads me to my main question: should I build window frames myself? By the time we come to build the house, we will already have built a workshop. I'm not a carpenter, and I realise anything I build will not be to the same standard as someone who does this every day. However I'm not in a rush and am able to do a reasonable job at most things given enough time, reading up ahead and the right tools. Our workshop will be kitted out with handheld powertools, but no specialist heavy bench-style stuff (pillar drills etc, although I may be able to justify getting something if it is likely to be useful in future).

 

I think the main factors to consider are:

• Certification requirements (CE marking?) etc – if this requires external certification it may just not be worth doing myself
• Not worth doing if I need complex machinery which we can't justify buying just for this project
• Cost in terms of my time versus just paying a skilled local carpenter to do it – I will obviously be slower. Of course the satisfaction of having built my own windows would be a plus, but not if they leak!

 

Any experiences others have had would be welcome. I realise it's not a straightforward answer and depends on several factors.

[nod]

All window frames nowadays are custom made Manufacturers now make everything to order 

 

Planners insisted on timber sash windows on our first build due to the neighbors being listed But allowed us to use wood grained UPVC 

 

[MattD]

Thanks @nod. That means that I can rule out buying off-the-shelf – one way or another, it seems that making use of this glazing would be the right thing to do. So what I need to work out is whether to build myself or get someone else to do it.

 

Our windows really do need to be wood framed (not just wood effect uPVC) as our build is required to have an ultra-low ecological footprint. Reusing existing glazing is another plus point in that regard.

 

Any thoughts anyone might have on the pros/cons of building ourselves (given a modest workshop and an 'inexperienced but willing to learn' attitude) would be appreciated. Any idea of the relative cost would be helpful too (in terms of materials only for self-build vs materials and labour for purchasing in). I also have no idea by how much providing our own glazing will reduce the cost. Clearly that limits us to local carpenters since they will need to collect the glazing from us first.

Edited January 3 by MattD

[Russell griffiths]

You won’t be able to do it, not to a good enough standard. 

Find a local timber window manufacturer and go and have a chat to them. 

Do you know the u value that was given to the sealed units as you will need this to calculate the overall u value the new windows will have. 

[nod]

32 minutes ago, MattD said:

Thanks @nod. That means that I can rule out buying off-the-shelf – one way or another, it seems that making use of this glazing would be the right thing to do. So what I need to work out is whether to build myself or get someone else to do it.

 

Our windows really do need to be wood framed (not just wood effect uPVC) as our build is required to have an ultra-low ecological footprint. Reusing existing glazing is another plus point in that regard.

 

Any thoughts anyone might have on the pros/cons of building ourselves (given a modest workshop and an 'inexperienced but willing to learn' attitude) would be appreciated. Any idea of the relative cost would be helpful too (in terms of materials only for self-build vs materials and labour for purchasing in). I also have no idea by how much providing our own glazing will reduce the cost. Clearly that limits us to local carpenters since they will need to collect the glazing from us first.

The company that manufactured our frames Like most don’t do there own glass So wouldn’t imagine they would object to supplying frames only 

[Iceverge]

1 hour ago, MattD said:

designing a new build to the latest regs

 

What spec are the glass you've recieving? 

 

Centre pane U-Value and G-Value and edge spacer design?

 

Windows are by far and a way the worst performing elements of our passive house, and of them, the window frames are the worst part. And they are passivhaus certified. You won't be within an asses roar of a good performing window unless you're prepared to become a complete expert, fastidious with details and spend days making each window. Then you'll be hoping that you've got it right in terms of stability and durability long term.

 

Glass units are generally cheap to buy so I don't think your neighbour has done you any great favours. Flog them on eBay. They'll only make pounds each and like @nod says buy they best performing uPVC windows you can.