MikeGrahamT21

Definitely fill the cavity which will end up internally, which will help to prevent the chimney effect of heat loss

Looking at your original photos, it’s definitely an improvement how it is now. You will find the white powder appearing (efflorescence) as they dry out, and as they’ve been wet for so long this is bound to happen, keep brushing it off with a stiff brush to keep it to a minimum. when I dug out to do external wall insulation below the DPC, I went all the way down to the foundation and it took around 6 weeks of fine weather for it to be completely dry, it will take some prolonged time especially at this time of year when it’s cold and damp most days

Yeah that’s right. The top guides on my unit can be moved slightly by hand so no load there at all. I was originally told that the bottom track supported units were more robust and also didn’t require any special lintel loading calculations so went with that

I can honestly say I like mine, but my opening is only 2m, I would imagine with the amount of leaves you are planning as above it could start looking quite cluttered when they’re all stacked up fully open, and may well look cleaner with a sliding door, but if you are set on bifold, then yes they are good, as with most things, if you get a good one. Don’t get top hung as they aren’t as robust as ground bearing. If PVC, Liniar modlock are very good, what I’ve got, 10 years in and they’re as good as new, just don’t get chrome hardware outside!!

They look very much like london bricks, as were widely used at that time, which are quite a soft and porous brick. Clear a bit more out of that trench, and then you're going to have to give it some real good time (and fine weather) to fully dry out, then it may be worth applying some brick protection, which allows the bricks to breathe, but essentially makes them water resistant. Of course also make sure the pointing is sound before filling the excavated area up with some gravel or a drain.

Yes i've noticed Eon rates have gone down for export, i'm on their fixed Export Exclusive V2 at 16.5p, but the V3 one currently the one you'd be put on is now 12.5p

I mean as annoying as it is, it was going to be changing to CPIH in 2030 anyway, so only looking at around 4 years with lower increases. the shadow pricing would be the one which would be an absolute no-no, that would mean no more yearly increases inline with inflation til the mid 2030’s. It’s would be technically difficult for them to achieve and therefore expensive so hopefully if any it’ll be option 1.

Plenty of ways to meet insulation standards of today, not sure a whole load of steel is very ecological or economical, but as you rightly say you can add internal wall insulation, as long as you achieve the stated U value requirements with your build up then you are good. Just don’t forget to have the cavity pumped with blown beads too!

Isn’t the 3m3/m2.h number related to this… It’s talking about carbon emissions rather than overall efficiency, of course the lower the ACH the better it will work but also doesn’t mean it won’t work at all. https://www.passivhaustrust.org.uk/UserFiles/File/research papers/MVHR/2020.04.27-The Case for MVHR-v7.pdf it is expensive though, I’ll give it that!

I go into panic if I’m spending more than £4 a day 😬 but then I think that’s more part of being a Yorkshire man!

I suspect you’ll probably need a G100 compliant export power manager style device, to limit your export to agreed limits

What size, type is your property and how well insulated is it?

A chimney breast will have zero issues holding 25kg, an almost negligible amount given the load capacity of a double brick chimney breast. your fixing strategy is over the top too, a fixing either end would work fine, and I’d probably up that to three (one in the middle) to stop the timber sagging. Don’t bother glueing the timber to the wall, as you will only be glueing it to paint/paper. the majority of these pre-made timber mantles actually hang on the wall much like a picture frame

If your BCO are like mine, they haven't a clue what MVHR even is 🤣

You shouldn't need to change the flow rate, thats what the actuators are for. I don't have actuators on my manifold, and have to turn the clear plastic tube to alter the flow rate, but yours definitely don't look like mine. Probably worth a call to nuheat, or see if they've a manual online?