Iceverge

Looking at some of your posts and the high levels of insulation you're after I think approaching a truss company to design something like this might work.

Or post tensioned stone effect lintels like this would look fine. https://www.forticrete.co.uk/products/cast-stone/structural-heads

Raised tie trusses might give you a lot of the effect for less cash but won't be truly vaulted. Otherwise you're stuck with collar ties or lots of engineering cals and most lightly steel.

any cross sections drawings to help us see what you've planned?

A thermal store is an option. A combi store unit would allow you to get rid of the F+E and keep the stove boiler whilst moving to a pressurised hot water system. No g3 requirements either. A simple direct UVC would work but you'd need to get rid of the stove boiler. A bit left field but an exhaust source heat pump would be a good option to consider too. Remove the boiler from the stove. excess heat generated by the stove could then be removed from the air to heat the water at 3:1 for the use of your electricity. @Thedreamer does this happily i understand.

Have you paid them? perhaps hold off until you're happy they've done a good job.

As per the title. The price seems low so I jumped at it. Pretty small resolution but hopefully good enough for DIY.

A wide cavity with full fill will transfer almost zero sound whatever you choose. Reveals, heads, jambs, windows doors and the roof buildup will be far more important. If you'd prefer batts go for it. @Tony and @joe90 have had some success. I believe.

Yes. Just make sure all your penetrations are done before blowing. Also you'll need to keep cavity ties clear. Cavity boards to catch mortar or a wash down daily of the ties with a before the mortar dries.

Batts are good if you install them properly. Beads are more tolerant of less exacting workmanship. We used beads to about 600mm below floor level in the cavity to reduce the thermal bridge there. Similar to the Denby Dale detail but much less labour.

Fair play to your builder for having a crack on a trial window but it's clearly a specialist job. His effort isn't really that bad and with a little practice with tightening the bonds it'd look passable for 99% of casual onlookers. The trouble is that he will be practicing on your job and the end result isn't what you want. I'd put him out of his misery and order something premade. https://www.brickfab.com/product/prefabricated-arches There's an option here that would achieve 90% of the architects look off the shelf without having to dig up some perfectionist bricklayers. I mean that literally, most of them who did this are dead with centuries! I think your architect has to be held accountable here, you pay for their specialist knowledge of building. They should have a broad appreciation of every aspect of the house and be able to specify something that is affordable and practical to build.

Some details show twin wall timber frames supported on one side only allowing continuous insulation from the floor to the wall. Either insulated raft on the inside or supported on a block and strip foundation on the outside. Maybe you could explore this.

Or use off the shelf precast lintels separately for both leafs. Standard practice here.

Having done the masonry route we had to fight hard for our airtightness and detailing and the build process was torturous at times. Concrete is sloppy, heavy, dusty, noisy going. It is cheap and pretty solid however but simple things like window installs feel like a best effort rather than any kind of precision fit. I think a dense pack cellulose or rockwool filled TF with a heavy weight 15mm plasterboard and skim would feel plenty solid, but it's best guess really and listenung to others experience. Having been in PIR insulated roughly constructed TF with thin plasterboard houses with no attention to airtightness houses they're a world away. In hindsight would you change anything about your TF?

We had a cold trussed roof so much different. Trusses are slightly trickier to get the membrane right. A ridge beam and cut ratfers would be idea. I'm in Ireland and I don't think ecocel cover the UK. Do you have any roof section to post to give me a better idea?

+1 for beads. Very fill fill. I checked our 250mm cavity. By drilling test holes. Some PVA was missing beads fell out where I cored a hole. Make sure you have all penetrations sorted first.

Masonry here. It's cheaper but hard to detail to high performance levels. Robust design and an excellent builder will be needed. 400mm+ Blown cellulose in the attic however. I'm a fan. TF next time.

Corrugated metal would certainly add to the racking strength but I wouldn't say it's needed if you have a separate racking layer. I would do 18mm floorboards as internal wall finish. Much nicer than thinner t&g cladding. 100mm Batt insulation between the studs. 9mm osb racking. Tape all joints of OSB externally as air control layer. Breather membrane. 75*22mm battens. timber cladding.

The vertical timbers in your pictures are only to hold up the cladding, much like battens over a stick frame building. It's normal for the breather membrane to be inside these as it allows the back of the caldding to dry into a ventilated cavity. If you push a membrane tight up against the back of the cladding you'll risk trapping moisture there.

This would be much easier to build. Tape the PIR at the warm side and you'll have a warm shed.

blown bead?

Would you consider a floor drain with an airless trap under the kitchen sink and in all wet rooms and not bother with changing the Flexi tails? It'd cover all situations, leaking dishwashers, tap, pipe, UVC, Kids flooding the bathroom. Its one of those "I wish I had" items.

Amen brother! We have literally zero penetrations throughout ours and it's still too much IMO!

Wind flow over the low-rise building models with gabled roofs having different pitch angles - ScienceDirect I didn't look too much into it. It's just a pretty picture that represents the wind flow differences at both sides of a roof apex. Do you have any more details of your install? Plans etc. The more info you provide the more lightly someone will recognise and already have a solution to your problem. We used one of these. Paul make something similar.

It's almost guaranteed have a vastly different external pressures with any kind of wind as seen above. It might be a nightmare to balance.