G and J

That’s where I was at the start of the process. The architectural technician who drew up our plans was also of that mindset, but by that time I was converted and so I quietly stood my ground. MVHR and a truly airtight house would never have been suggested to us.

I’ve learnt a huge amount over these last months, planning our build and with my nose firmly buried in buildhub. If i think back to when I started I recall that I could never have believed how important airtightness is to the overall thermal performance, so if I put myself in the shoes of an engineer trying to dimension a heat pump, without the benefit of an understanding of the massive affect of airtightness, and with an eye on the history of heat pumps and the very public moaning over their efficacy, then I can see me falling into the trap of oversizing simply because I was trying to do the right thing for the customer. So I sympathise with both sides of this. It feels like early days in the UK building industry as far as airtightness is concerned. I imagine for many in the trade it’s another stupid rule imposed by idiots who don’t have a clue. I imagine in a good few years it’ll be in the industry’s DNA. Until then it’ll be a wrestle sometimes to get the right result.

It used to be if you left a corner of a wall you couldn’t reclaim the vat. As you are bracing the party wall that might be deemed to leave a corner. I’d suggest you tread carefully with respect to assuming a vat reclaim will be successful. Would have thought clarifying that with HMRC might be good.

So, if i understand correctly, you (well, your ‘friend’) had planning permission for an extension but always planned to demolish anyway?

I believe the one ringed in red will trip if there is an imbalance in the current in the live vs the neutral, i.e. some juice is leaking out of the circuit, usually to earth. (In this case probably through a still gooey mouse corpse - but the good news is they dry and as they do their insulation level increases till it doesn’t trip out any more). The one ringed in blue will trip if too much current is taken. Say if the mouse body is shorting between the switched wire (i.e. a live wire) and a neutral. You could wait and see if said body (or bodies) dries enough to save you having to firkle through the loft. But popping your head up to put some good snap traps up to reduce or remove the population would be a really good idea. I’d not recommend bait, it encourages them in (they think it’s a yummy food source) and then they die and stink. If you are going to bait, do it outside and reduce the population nearby. Our experience is that that is the most effective long term approach.

Brill. I trust Aviva. Will be giving the broker a call today.

Thank you. Protek are in pole position re site insurance. Wading through the warranty documentation is next week’s job (I know how to live it up at Christmas lol)

Reposting, as realise original title not too informative! "We need site insurance as well as a warranty. So I went and got quotes from Protek, SelfBuildZone and BuildStore, only to discover that the SelfBuildZone and Buildstore appear to be the same company giving the same quote. Sigh. So folks, who should I get a third quote from? We've both party wall agreements and demolition in the mix."

We need site insurance as well as a warranty. So I went and got quotes from Protek, SelfBuildZone and BuildStore, only to discover that the SelfBuildZone and Buildstore appear to be the same company giving the same quote. Sigh. So folks, who should I get a third quote from? We've both party wall agreements and demolition in the mix.

Crumbs! I think if I were in your shoes I’d want eyes on the bypass valve anyway for my own piece of mind, regardless of the UFH and certainly before I chop the circuit, but I do have a tendency to overthink. I find it difficult to believe that a bypass will have been shoved under a floorboard in the wing you are isolating, but that doesn’t make it impossible. If you are putting UFH in that wing I presume you’ll be having all the floorboards up anyway so you’ll find out. Anyway, I’m used to systems where all rads bar one can turn off with a trv OR all rads can turn off and a bypass is fitted. Maybe whoever fitted the system left instructions always to leave at least one rad open. Assuming you’ve only got one pump then as long as you are leaving other rads open I can’t see why isolating the wing would be an issue. But then, every day is a school day. Just don’t try it on Xmas eve lol, just after all the merchants close.

I don’t know but I’ve always assumed it’s due to temperature cycling - my loft temperature varies wildly over the year. Perhaps there’s an ideal torque that a screw connector should be tightened to to avoid it but I’m damned if I know what it is. Anyway I’ve got the hump now so I’m withholding my well meaning advice nonsense (until I see what sort of device is tripping out).

If you close the valves on the rads affected by capping off at the point indicated does the system run ok? Are all those rads on trvs? Iris one or more of them permanently open, indicating that they are the system bypass in case all other rads/trvs are off.

A thought. Stand an iPhone or iPad (or rather low rent android equivalent lol) next to your heat pump and set it to record on voice memos. Go back an hour later and you can see a graph of the noise it produces. I’ve just done a quick test using my voice (best I can do right now as we are a heat pump free zone) and this is what it looks like.

Our softener here has a through the wall type overflow, which is what I’ll do in the new pad. That’s ok for us as the water softener will sit in our garage outside the airtight envelope. Not sure how one would do it if it was inside the airtight membranes.

OK. I give in, (and I accept my googling technique clearly leaves something to be desired). I can’t find a UK seller of mineral wool filled metal roof panels. Anyone know of one?