Iceverge

Lots of confusion re vapor as usual here. Its like worrying about a mouse when there's an elephant in the room. Airtightness is the real bogeyman. Poor air sealing allows hundreds of times more damaging vapour into the wall than vapour diffusion does. Not to mention the outsize effect airtightness has on building comfort and efficiency. I see you've been seduced by the headline K value of PIR to put it in-between the studs too. I wouldn't. It'll age differentially to the timber and you'll get gaps around it. You'll end up throwing lots and lots of offcuts in the skip too. Keep the mineral wool if it's still in good condition, perhaps add another 50mm to ensure the studs are full. ( I assume the studs are 140mm CLS at 600cc? Then an airtightness barrier. Then cross batten and insulate the service cavity. Very buildable, very little waste. A workable robust airtightness strategy. Much cheaper than what you proposed previously.

Can you copy and paste someone else's?

Why can't you keep the megaflow?

I'm not an SE but the farmer in me would like to see some foundation bolts well cast in to the concrete or else some galvanized straps tieing the frame down.

Not a quality job unfortunately. Does the house have an external layer of masonry? If not I would be very apprehensive about those fixings being butch enough.

Welcome welcome. We all love problems. Espically when we can pat our egos by solving them! The simplest solution looks to be to just screw the brackets directly into the rafters tails. Why wouldn't this work?

Looks good. Look forward to seeing it take shape.

Yeah it's interesting alright. Out of interest can you accurately model an air leak? For instance a badly sealing patio door with a 1mm gap over the height and a corresponding rattled sliding sash window on the opposite face of a building in say 10m/s or wind?

Wider lintels won't be needed unless you're using those silly catnic things. Just use separate precast concrete one on each leaf.

Computational flow dynamics?!

Don't do this. Moisture will get stuck behind the boards.

Be cautious of Ubakus. It's imperfect and shows a snapshot, typically of -5 outside. Unless you live in Greenland that isn't a fair representation of the lightly seasonal behaviour of the wall. Lightly in the UK the weather will be warmer 360 days of the year. No need to remove the existing plaster. Just patch up the holes and make sure anything at a penetration is sealed in a manor that won't crach with slight movement, tapes airtight paints and silicone are all fine. There's so much nonsence talked about vapour barriers. It really is almost nothing compared to leaks casued by airtightness. Concentrate on great airtightness, add mechanical ventialtion and you can get away with as much internal insulation as you like proviced it's not vapour impermeable like PIR.

A blocklayer is more than capable of installing cavity batts correctly. It's a technically much simpler thing than putting a cavity wall together. The industry never trained anyone to do it properly, manafacturers make unworkable products (rigid cavity boards), and there's usually zero oversight and reward for a job well done. We still pay per block so effectively want the insulating job done for free. Brickies who make a good job of it loose money becuase they havn't been paid for their time. Setting up the incentives so negatively for any human and getting a bad result, it's a bit rich to blame the individual.

Both fine. Will last 60-70 years with some care. Tiles look chunkier, slates look flatter. Natural slates will last twice as long but cost 3 times as much.

Preach. If uPVC was there times the price everyone's would think it was amazing.

Agreed. Everything is always behind you. Islands are for cookery shows so the cook can face the camera. The public got confused, thought that they were on TV and everybody else needed to see them peeling turnips. Turns out, nobody's going to watch that.

Great value. I'd do this if I was to new build again.

Whats your exact buildup? It's a good product, offer some drying capacity, hard to tear, offers very good airtightness but as Mike says it's not magic. It won't do much if not installed to an excellent standard and it's very expensive to boot.

As much as I can be, the UVC is too far from the kitchen tap in our house though. I think maybe 13-16m? I would use 10mm to the kitchen tap again as 6l/min is fine and it really speeds the delivery time. It also stops the Mrs pouring too much hot water directly down the drain. We get 10l/min at the tap if needed just by blending it down a little with cold. I did the same setup in my parent's house. Speed of delivery trumps flow rate in my view. We too have an A2A unit as the main heating so no water heating available . If we had an A2W ASHP I would certainly use that but the prices we were quoted would never have made sense given our small heat load. PV and divert is the eventual plan but the ~€400/ year (3500kWh) we spend on hot water on a TOU tarriff won't break us. At a guess you'll be double this usage for your house. The money for the PV is making far more use of itself as AVCs in my pension at the moment anyway.

That's ours. More pipe clips would make it prettier. Note the thermostatic mixing valve screwed straight into the cylinder and then the manifold directly above it. The. The first pipe away is the kitchen tap (10mm for us). The water in the manifold is preheated by convection so theres zero dead leg before the manifold. I've since removed the second stopcock and lowered the inlet group as it too was warming by convection. The only changes I think I might make to this if starting from scratch would be to lower the inlet control group more and move the tundish to the space between the tank cold feed and the cold manifold for tidyness.

When you have a cylinder with heaps of fittings and coils and extras this is an issue. Jeremy had a problem with this. Ours is a simple direct 300l UVC living in a 2m2 cupboard and its never much above the house +2deg at a guess in there. Even in the height of summer. I would argue against this by default. The price different of the cylinder Vs a direct one could pay for a solar diverter and a few panels if you're committed to immersion only heating.

Yes to UVC. 300 litres is too small for that many people if you plan to heat exclusively on a TOU tariff. Get 2*300l and be done with it. 300l is the most bang for your buck the last time I checked. We manage to store enough for 2 adults and 3 kids with 300l and 70deg storage on a TOU tariff 30mins showering and a large bath and a bit of washing up I about what we get from it. Run everything in 10mm Hep2O except the kitchen/utility tap and baths/showers. The delivery time will be small even at 15m run length. Don't bother with anything fancy like return loops or external manifolds or remotely heated sinks. Just flick the tap for a few seconds. It'll be way cheaper on the long run. Don't bother. The dishwasher will be already almost full of cold water from the pipe by the time it gets any warm water from the tank.

If you need to make significant fixings you could always cut a section out of the insulated plasterboard and replace it with ply direct to the wall for a solid surface to fix to. Have the cavities been insulated? EPS beads would be my recommendation.

If you don't want to have a raised base to the shower it's stuck in that corner. Although drilling through joists and adding metal strengthening plates is not impossible I believe. To a certain extent everything else can happily be moved where you like it as built in vanity, bath surrounds all conceal pipes nicely.

Great result, well done.