Solid Wall insulation internal - without buildings regs

8 Aug 2016
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United Kingdom
I know how stupid this is, but naively we installed internal wall insulation in several rooms (external walls). Solid wall house. Had no idea there were regs for this, just thought that adding insulation was a "good thing to do" (yes, ... I know better now).

We used Kingspan materials and it appears from their website calculator that we did make it thick enough (62.5mm) to meet the U value targets for this. Work done by family builder who probably knew what to do, despite no regs.

If we regularise this work (I've been doing a lot of googling) what will buildings regs want? We have samples of materials used still, and in one room no redecoration has yet occurred, so its easy to see. The other room have been redecorated - will they want to drill holes or dismantle to inspect? The thickness can be measured (approx) in those rooms. Are there other issues they might ask about e.g. damp?

I've been trying to decide what to do. I'm a cautious person and would never have done this deliberately so I would like to put it right, but is this wise at this point in time? There's one room I would be really sad to have to dismantle. I'm really in a quandry about this. Thanks for any advice.
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I wouldn't bother.

This is not safety related work, and the only reason I can think of that you might want it inspected, is if you don't think it's been done correctly and may need to pursue the installers.
Thanks for the replies. Won't it be a problem when I come to sell or remortgage?

I won't be pursuing the installer - he is closely related to me!

I think the work is very likely to be ok but I am not sure how hard it is to prove that retrospectively. It really makes a big difference to the comfort in those rooms (and bills).

We've been doing it as we do up the house (slowly) but the irony is we won't go on doing it now as because we've realised it costs an extra £300 per room in building regs (on top of the work costs), which alone makes it no longer economic.

I've realised, Buildings control must have seen it (because they came to inspect something else in the same room) but did not comment. Does that mean they are not really interested in this type of work?

Thanks again.
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You've not made the situation worse, so what do you think is the problem? I feel like I'm missing something here.
Did you strip off existing plaster before applying the boards? If not, I'm not sure you would have needed to make a Building Regs application anyway.

It wouldn't have cost £300 per room to apply for a regularization, but even so, the additional cost of that bit of paper would push your pay-back time well into the future, and personally I wouldn't bother.

Whatever, just stop worrying about it and enjoy the comfort and cost-savings.
The situation is just that it has been done without informing buildings regulations, so I guess it is not legal and this might be an issue when I come to sell (and I want to remortgage soon).

I read the part L buildings regs last night and as far as I can see you are supposed to apply whether you strip back to the bricks, or are just applying above existing plaster (We did the latter). I could be reading this wrong of course.

Yes, it does genuinely seem to cost PER ROOM locally because we've been only doing it gradually on a room by room basis and the price is per "unit of work" cost. So just the buildings regs alone makes it uneconomic to do on a room by room basis, which seem nuts when we want to get people to insulate and reduce CO2!!!

There is something about not needing regs if you only do 25% (or 50%, I forget which now) of an external wall, and I did wonder how much time there needed to be between the 25%/50% done before you do the rest .... Or am I overthinking this?

Thanks. I tend to worry and anything else done has or is being signed off by BC.
You certainly live up to your user-name.

Technically, you are probably right in that 'renovation' means 'the provision of a new layer in the thermal element....etc'.

No Building Regs dept would charge you £300 per room, they would regard the 'unit' as the whole house.

But if you've got all the other paperwork in order, why bother even mentioning this when you re-mortgage??
Do lenders really care about insulation anyway? [I guess not that much].

I am also too honest. I wouldn't be able to not mention the insulation work when I come to sell, now I realise that regs are needed. Perhaps I can for the remortgage and deal with it later. So, if I put in buildings regs later for another room (one not done yet) will we get the whole house signed off for insulation, do you think?
Thanks for all the comments also. Seems like I am just worrying too much, helps get it in perspective - it is nothing safety related after all
Seriously, spend the cost of regularisation on vino. Nobody will be the slightest bit bothered by your adding a bit of insulation to your rooms. Except the police helicopter that is - if one flies over pull the curtains in case they spot it.
As above, crack on. When it comes to sell you'll have a sellers questionnaire and where you have to list the works you've done over the last ten years, either a) don't bother listing it b) say you've 'redecorated' various rooms. No solicitor will ask any more questions, and the lenders won't care.
I put in buildings regs later for another room (one not done yet) will we get the whole house signed off for insulation, do you think?

Only the Building Inspector can tell you that. But it would be a very unreasonable one who would refuse to put the whole-house wall insulation on the completion certificate.

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