Iceverge

I'm glad you've found a good company. That's probably more important than anything. I know I'm banging a PVC drum here but I see they do Veka profiles. I would price Alphaline 90 and Softline 82 and go to see a house with them and alucald both installed after 10 years and compare. You could see a £30k swing the other direction and a lower maintenance better performing window.

Apologies for my hiberno slang. Just glancing at the section of the window I wouldn't be sure it was a top performer in terms of air sealing and thermal conductivity. I would like to see more seals and insulation. Something like this with 4 seals and thermally broken too. The Uw figure looks fine as a whole but just be cautious of it as large areas of glazing with a low Ug can hide poorer Uf figures.

Those frames don't look hectic. What's the Uf value?

Wider cavity. It's not rocket science. We have 250mm.

Where's North?

I have a basic cheap flymo from about 10 years ago. It works fine on a flat lawn. I never bothered switching it off. Let it run all winter in the old house. I never got around to installing it in new build. It will get stuck in any hole bigger than a cup. One thing to be careful of is the mowing height. Too low and the grass will get weak and the leather jackets will have a field day.

Preach.

Nope, it's about 60% dearer than the readymix lorry. The cheapest way to get concrete is from the mixer truck..

Having used pumped insulation in the house attic and mineral wool batts in the garage I would happily say it's one of the best things I have done with the house. No itchy and scratchy show. I think @Gone West priced supafil when doing your house. Any idea of the cost installed? If you could find a machine to blow this behind a clear membrane you would have a cheap solution.

What's the UK price now? It's 4-5 years since I priced it here at €150/m3. Fitting mineral wool isn't particularly nice as jobs but it's very doable. Has anyone done blown mineral wool?

Tilt and turn baby. Tilt and turn!

Are you planning on stick building the frame? Have you considered blown insulation AKA cellulose. There's lots going for it.

Good layout, Nice to see a sensible square foot print. Personally I would pay the digger man another hour to level the site and forget about the step. It will make half the house unusable for anyone with a wheelchair or a pushchair.

Sliding sash looks pretty but is the draftiest window you can buy. I was in a new build of some neighbors, 0.15 walls floor and roof, compact foot print, wet plaster and plenty of airtight tape and MVHR. And sliding sash windows........ You could feel the cold breeze on the back of your neck sitting in the kitchen.

Any pictures? Is it mid bearing of the hollowcore slab or end?

You don't absolutely require MVHR, dMEV will give you adequate fresh air at less capex and slightly higher opex. However you'll have holes in the windows and you'll miss the chance to filter the incoming air for dust pollen etc. You will have more outdoor noise and drafts. I think your plan is a good one as you said. To throw a spanner in the works you could have an air driven heating system and allow the A2A units do everything and omit other central heating. There's drawback there too but it is a option.

I think this was on a forum here recently but I can't remember for who. 0.18W/m²K is just about achievable with a mineral wool 32 batt and 150mm cavity and some kind of light weight block inside. In reality I think a 200mm cavity and a cheaper 0.36 batt is better.

I assume you put battens inside the pir layer? 75*25? Did you have any issues with keeping them straight to hang the plasterboard?

100mm pir might be cheaper than 90mm. Worth a look.

Opening. I like to towel off ina cool breeze.

ubakus?

Mix up mortar 4:1 sand cement and trowel it into the chases where they're too deep. Maybe easiest done when the electrician is fitting conduit and push the conduit into the wet mortar. I know you're concerned but I wouldn't be too worried so long as everything is plumb.

I wouldn't worry about it. The calculator takes a snapshot of a temperature and assumes it stays -5 deg forever. Not very realistic unless you live in a valley somewhere that never gets any sun. Masonry is very tolerant of any damp. Masonry wall with mineral wool is somewhat vapour open so drying does occur both back into the house and out through the wall .

I could probably do any build method myself, masonry included. Unfortunately I would be long dead before I had finished. I think stick built has great advantages. 1. Speed 2. Many options to source materials locally 3. "Standard" TF constitution these days for mortgages and insurance etc. 4. No big deposit to find. 5. Easier airtightness + thermal bridging details. 6. No mega machines needed. Masonry is good but to make it work well you really need a simple box design, good masons and plasterers, a longer time scale and time for tricky airtightness and thermal bridging detailing. It's not impossible but for a high performance building (we did it) but it's more touble than it's worth. If you're will to accept something average it's fine. ICF and twin wall factory frames are excellent when done well but carry the risks of higher up front cost, waiting times, deposits, scarcity of extra materials if needed. Big cranes on site. Sometimes awkward insurance and mortgaging. Pick your poison.

That "mineral insulation panel" has a k value of 0.045W/mK. try it again with a "mineral wool 035" or "hk 33" for the EPS beads.