Alexphd1

Your figure are pretty close. Think 380mm approx 0.1u. The graco agent in Leeds we bought the machine from had a few 2nd hands one aswell for a few £k less. Getting open cell bba certified foam is tricky, plenty non certified but there is a few suppliers going through bba at the moment. This is not a easy option, lot of time involved researching etc.

Installed cost is similar to purchase cost of pir/pur. You can DIY, because we are! We are splitting the cost of machines between myself and father (2x builds). Cost ways we are away ahead but I believe we are getting a good product at the end of the day!

Have a look on you tube and search kishorn insulation, it's a promotional video but pretty good (No comnection) I am not 100% sure on how good it is for decremantal delay but I believe it's somewhere in between blown cellulose and pir. Also the added benefit you it's pretty good for air tightness.

If you like duriosl icf have a butchers at velox icf.

I don't like to openly criticise online other products but I ruled out duriosl and integraspec very early in my project. As Russel says above prioritise what you are looking for and start from that.

Would be framed and plaster board inside. I would like very thick insulation on the outside of my concrete with NO thermal breaks in the insulation, just like a tea pot cosy....

Trust me two house is not a luxury..... I have got to go through this again next year....make your brother go first and learn from his mistakes.... In the grand scheme of things a extra few hundred pounds for pumps travelling time ain't going to make a fart of difference.

I really like the look of the single sided nudara icf which you remove the timber form from the inside to expose the concrete. Add on a 200-250mm EWI with chemical and mechanical fixings on the the nudara external ICF (as @Stones in Orkney done with amvic icf). Stick all this on a DIY eps insulated raft foundation, 400mm open cell spray roof.... simple😉

Integraspec is another decent ICF but i am not really sure the advantage with "chamfered closers" over most other icf manufactures eps cavity and lintel closures. Have a good look at amvic and nudara icf (they are not market leaders for no reason) visit a few builds esp on pour day. Don't just listen to the sales reps or a "expert ICF builder" who has only done a day course with a ICF manufacturer (came across a few of them).

We used Nudara and will be using it again next year (as long as price is competitive). There is alot of suppliers on the market all with there unique selling point, as russel says above make a list of what you need and starting from that.

£200 mentioned above for a extension is a lot less than I was expecting. For our build project I don't see what value a QS could bring to the project but we are not a normal build.

There has been a few threads on buying lighting from aliexpress with @AliG lights looking very nice.

I think it could/would be a very good solution for on site timber frame build. It is possible to do a DIY (we are doing it) but you need a lot of m2 to make costs/work add up.

£30m2 @ 300mm thick is a number which sticks in my mind. Can't remember U value. You get a pretty good air tightness compared to hand cutting rigid insulation.

Are you looking at a DIY basis or getting a contractor in?