Nickfromwales

Ditto. SIPS would be my last choice, but then I’d just go masonry and simplify.

You’d need to see this for yourself, or accept my ramblings about just how good this is. It’s like pouring liquid PVA into a gap and it being left to cure. It’s nothing like fibres, just atoms of the ‘product’ that hit each other, bond together, and then cure in situ. The depth of the gap / void / crack has the product disappear more deeply into, then as that closes less and less heads in, but when sealed it’s a very good, penetrating seal. It’s like hammering more and more wedges into a gap I guess. In terms of longevity I would only think it would fail if left exposed and subject to mechanical wear and tear, but once covered over it’s there to stay afaic. This has been used for some time in the USA, so maybe search across the pond for reviews / instances of failure or issue perhaps?

Give it to the architect if you want to burn money, or get it near as damn it before doing so and reduce the pain.

Is that the WiFi app? Has it just lost communication?

The truth sometimes hurts

Did they demonstrate how long the 2 loops would each be? For this amount of m2 I would be looking elsewhere as the loop lengths would be crazy long, and the effectiveness of the loop pretty dire; energy disrupted into the slab would soon sap the heat out of the pipe long before it had returned to the manifold. Thos installer needs to be binned off afaic.

5 bedroom needs a system capable of 6 person occupancy. Your ‘advisor’ shouldn’t suggest a system of lesser capacity. Get an air-blower based treatment plant, and leave the coconuts to the good people that make the Bounty chocolate bars .

First obvious one, just do a flat roof. You're losing head height for no reason. An EDPM 'rubber' membrane can be flat as a witches tit, or GRP same, with either just needing a whiff of a fall off to one side to function if preserving head height internally is a big box to tick. Sketchup is what a few folk on here use for detailed DIY drawings Lots of other stuff available, others will comment I'm sure. Going below grade outside renders you being at risk of of flash flood / excessive storm rainwater finding its way in, so you'd need to understand the permeability of the ground and where the water table resides before even considering dropping down. Your foundations are huge, so just ditch the masonry and go for a lightweight twin-wall timber frame arrangement, well insulated, and whack some cheap AC in there for heat / cool. Zero need for the masonry walls, but you probably do need to have a solid floor / slab. You could incorporate a recessed area aka sump in the centre of a poured slab where the treadmill would then live (a bit like a pit in a car mechanics garage), to get you another 200-300mm of useful head-height when in use. I'd prefer my chances tanking and waterproofing that than dropping the whole slab that far down.

Did they glaze these on site?

I’d defo say go alu-clad vs solid aluminium. Condensation is a bitch. If alu then look intensively at how / if the frames are thermally broken.

I wouldn't leave it on show! I'm referring to using it for fundamental sealing and weatherproofing, only, with decorative rain screen meeting the frames of the units so hiding the 'seal' behind.

Are you challenging me to a dual sir?

The gap will be dictated by the supplier, for eg Norrsken wanted 10mm each side, and 10 - 15mm above, and to be able to pack out 3-5mm underneath to level the units. Don't order any products until you have these particulars FWIW, why Compriband? FM330 foam and then something like clear CT1, applied after the foam has cured and been cut just shy of the surface, does a splendid job and is (afaic) easier and more robust. I prefer to have a continuous bead of mastic 360 degrees around the unit to provide sealing / weathertightness etc. You can also CT1 across the face of the packers, whereas with Compriband you have to stop and start in between the packers which is a bit shite.

Whatever has been added to the very original house is another bite out of your PD. Why aren’t you just simplifying this by going for a full planning application? If they refuse at least you’ll know why and what’s not ‘acceptable’, but nothing stands out as offensive or domineering so I doubt you’ll have issues; unless the planning officer was bullied at school.

These are difficult to get right when they’re planned and executed to suit. Retro-fitting these will be crazy difficult, but not impossible. You can do anything in reality, it’s just time / cost / quality and this will need a boatload of filling and sanding to get it looking right. If someone rang me to ask me to do this as a paying job, I’d be adding a few zeros to the bill and clearing my diary for a month.

LOL!

Yup. Zero chance of getting anything in from outside. Seems an ok job so prob just needs the air to stop moving about under the unit and BINGO. Have you used a foam gun before? It’s such fun (not) if not?

Not how to live, but I’ve had to do similar in cheap rentals when me and the missus moved in together 30 odd years ago. Laws / regs / acceptable minimum standards have changed now, so this just shouldn’t be happening. 16°C is terrible, they keep prisons warmer than that.

Exactly the type of property that should never have had an ASHP installed on to. So many useless tossers happy to take the money and say nothing. Whats the EPC?

Or ICF Sorry mate, there's only room for one. 10/10. Consider AeroBarrier for the airtightness of the existing. Just done a hybrid masonry / posi joist roof refurb, and got the AT score down to <0.20ach as I am a fecking wizard lol. Norrsken doors and windows, blown cellulose in the roof + AVCL and the parge and liquid airtight membranes where necessary to get the results. ASHP and UFH now operate at crazy low temps, tres bien!

Defo a new slab and footings, as b regs will not allow space heating in non-insulated spaces due to terrible energy losses. You're not even supposed to put a radiator in conservatory as they have open ventilated ridge details. You could sample the slab and see if it's robust, and if so you could just bond PIR to it and build up to the level of the doorway, less the thickness of the floor covering, but in honesty once you disturb this for footings there will not be much worth salvaging. Better to lift the footings and lay the slab so you step up into the new porch, to weatherproof it, giving ample opportunity to insulate and then heat it with less losses.

@Bitpipe?

Why PD? Why not go for the original design if a downstairs additional WC is required / of long term benefit? A planning application isn’t likely to fail here imo.

This would require a LOT of EWI, to get these two sections (old and new) to be anywhere close in comparison. Have you included increasing the soffit and roof overhang to accommodate this properly? Seems the new extension will massively out-perform existing, eg you’re in Passivhaus territory with the new, so without airtightness and MVHR (assuming this?) are you sure this isn’t just a little OTT?