Calculating window U value

[Chrispy]

I've been asked to make some windows for a customer, now although I have made many windows before I've never needed to provide a U certificate, this time I think I might have to, so far I have found a website that says they will do this for £35 a window, is this really the only way to go or does anyone know if I can do the sums and self certify?
£35 per window seems like quite a tax on the small business owner just to make a window!

 

[Random Orbital Bob]

dunno if this helps

 

[jimmy_s]

you should be able to do the calcs and submit - not that difficult to calculate.

 

[Chrispy]

dunno if this helps

Yes I did find this one but it is for their own plastic frames! Any design as long as its made their way with their system.

 

[Chrispy]

you should be able to do the calcs and submit - not that difficult to calculate.

I hope so, I just need to find out where to learn how. :?

 

[jimmy_s]

If you want a hand let me know - its part of my job having to calculate U values, it will take about 5 mins to do if you have the details of the window.

 

[Chrispy]

If you want a hand let me know - its part of my job having to calculate U values, it will take about 5 mins to do if you have the details of the window.

That's fantastic news, so it is safe for me to take on the job then, and if they need the certificate I can do the sums and self certify, when I draw up what they want I will get back to you if I may. Thanks.

 

[oakfield]

I looked in to this a while ago when I was asked to make some glazed door for a customer who worked for the council - I wanted to make sure it was 100% done by the book!

From what I remember there were 2 ways of doing it.
Either calculate the u value of the whole window, taking into account the size, shape and material of the frame, gaskets, glass etc. this is when you need complicated calculations, expensive program's, or pay someone to do it for you. This needs to be 1.6 or better
Or you can just fit a sealed unit that is 1.2 or better. This is what I did.

 

[HOJ]

I have the same dilemma, just picked up a potential job to replace 12 UPVC windows in a cottage, for Oak.

Looked at the Joinerysoft option, and worked out at over £10,000 for all the modules!!!!!!

I know Fensa offer a service, but not sure if I want to join another scheme, I normally work under Planning and Building Control/Conservation offices

I am looking at this at the moment, http://www.thermalcalconline.com/u-value-calculator/u-value-glass/u-value-glass.html not really had chance to go through it yet but looks interesting.