DIY Windows and Building Regulations

[siggy_7]

Apologies if this has been covered already, but I did a couple of searches on the forum and couldn't find an answer to my specific question.

I am thinking of making a couple of windows up for my Mum - she has a bay window and a large window half way up a staircase that leak air through the frames and have condensation issues due to the failed glazing. The existing windows are wooden outer frames with aluminium-framed double glazing inserted into rebates in the wooden frame. When mentioning this to a colleague, they suggested that I would encounter problems with building regulations that I wasn't aware of. Researching around the topic and reading Part L1B of the regs, this appears to be the case.

My question is, if building the units and installing completely myself, what is the process I need to follow? I understand that the new windows need to beat a target U-value of 1.6W/m²K for the whole window. The glazing units I buy in (I'm thinking of low-e laminated glass with an argon fill) would presumably have some certification as to their thermal performance, but given that the regulations talk about the whole frame and also considering air leakage based on testing how does this process work for windows not built by a certified manufacturer? I understand that I can get a local building control approval for the installation if not done by a registered installer who can self-certify which costs around £100 for 1-10 windows - does that only cover installation of complete window units that have been certified by a manufacturer, or does this also cover a non-certified construction where presumably an inspector would look at the certified glazing units and quality of the construction, do some empirical sums and come to a view as to whether the target U-value has been met?

It all seems like a bit of unnecessary hassle designed to ensure that certifiers can make money. I'd be tempted to avoid the process completely as what I would build would likely meet the standards anyway and be demonstrably much better than what is currently in place. However, as it's on behalf of family I don't want to create a situation where any future regulation compliance query or house sale is complicated by something that could be avoided at this stage.

 

[fluffflinger]

Did some research myself on this and concluded that reading all the various bits of legislation that may or may not apply to replacing windows made my head hurt and made me want to jump out of a window rather than construct one.

In the end I put in a call to my local building control officer and he said that they would need to see the rating for the DG units and confirm by physical examination that they were happy with the construction, after that he would be happy to approve under a simple building notice.

Note I do not live in a conservation area and I wouldn't take my word for it but a simple call to building control in your area might be a good place to start.

 

[Bradshaw Joinery]

It will have to comply with a centre pane u value figure (so the glass u value) and the window itself fit for purpose, safe, etc etc as its classed as a one off and built in a traditional manner.

http://www.bwf.org.uk/news/question-of- ... l-doorsets

 

[kostello]

Could you 'repair' the existing wooden frame by fitting new sashes etc......


Repairs to existing windows are not covered by building regs

 

[Dibs-h]

And what may I ask is wrong with making them up for your Mum and just getting on with fitting them?

Dibs

 

[Jacob]

Yes just get on with it. You could say it's remedial work and not replacement. There aren't any window police out there waiting to jump on you.

a simple call to building control in your area might be a good place to start.

Don't do it!!

NB there are usually easier ways to deal with condensation and draughts, rather than replacing windows

 

[RogerS]

Keep the frames. Then it becomes a repair and not notifiable.

Or if you do want to make the whole lot up, then go to the Mighton site and providing you use their stuff etc then it's covered as they have done all the hard work.

 

[siggy_7]

Thanks for all your responses.

Did some research myself on this and concluded that reading all the various bits of legislation that may or may not apply to replacing windows made my head hurt and made me want to jump out of a window rather than construct one.

I know the feeling, trying to get to the bottom of what standards need to be met in intelligible terms is something of a challenge! As with a lot of these things, there isn't a universally adopted set of terminology with different ratings that mean different things, and trying to understand what they mean in relation to one another is nigh on impossible.

Thanks Bradshaw Joinery, I didn't know about the centre pane U-value. Looks like if I target a glazing unit U-value of 1.2 or better from the suppliers then I shouldn't have too much of a quarrel with the building regs people. I will double check with them though. I agree with some of the other responses that it would be much better to just get on with it outside of building control, but I've heard from a colleague who is going through a house purchase at the moment that this sort of thing is beginning to crop up a lot in surveys etc when homes are sold and I don't want to create more problems than I'm solving by doing the work myself. The frames are early 80's and quite far gone unfortunately, much easier to make up new ones.

 

[Modernist]

It will crop up if the surveyor is half decent and will then lead to problems. This is currently a bureaucracy growth area!

I made all my own windows to a high spec and installed triple glazed units which obviously exceeded the regs. I then had to get them inspected by the BCO who was no problem and free.