Alexphd1

I like ashp's, I like oil boilers but I fail to like the idea of combining the two systems together. Sounds like the control system could be a pain in the ass to mantain/repair further down the line. I would keep the system as simple as possible (although I have failed on that with our hybrid system). Have you seen the price of the vortex air unit?

We are away to dump this....

That's a new one to me. Looks like it's made in Germany. Looks a pretty standard icf product.

First off is a vented or un vented tank, you may struggle for height for feeder tank if vented. If changing style of tanks the job may take longer than a day. Very hard to give you a rough price even on a simple job without seeing the job.

Combis are good for smaller properties and can give you a good shower but if it was my own property a system boiler and UVC everyday.

I think willbish is pretty spot on, our 1st day after pour we just walked around with a grin on our faces. Couple of days to remove bracing before even thinking about building next course. Forget about bonding coat between pours unless waterproofing (you dont put a bonding agent between traditional concrete block wall?) Generally you pour one floor at a time but every build is different. Biggest recommendation is find someone building with ICF and be there on pump day.

First thing I would do is check your mains water pressure and flow rate then work from there. Personally I would be more looking at a small system boiler and a 300l unvented cylinder. If the boiler short cycles on ufh then add a small buffer. A UVC should last at least two gas boiler life spans. A system boiler is more reliable (less parts) than a combi boiler and you have always the electric immersion back up for hot water you could also add a immersion to buffer for electric back up. If you have PV it's easily to dump excess in hot water tank. Piped correctly and decent water pressure and flow rate will give you 2 good showers.

I have a problem to remember to switch of lights.... is there not something on market to fit on downstream of meter to stop exporting electric?

Forget the cost pay back for a minute but how could i fit a large Pv system say 15kW in a domestic home and limit the excess power into the grid or stop altogether going into the grid.

The first timber we got supplied and delivered by local build merchant where also as you describe. Speaking to a local joiner he laughed when we was telling him about it, he hands pick all the straight timber and leaves the banana wood on top.... sounded like the build merchant just off loaded the shite of the top to us! I like the look of that stuff Russel speaks off.

It has gotten a bit of topic on how from how to straighten /prevent 6x2 timber from twisting to installing timber plates for 1st floor icf. @scottishjohn it would be a lot of work to remove beams and replace as you mention. This is a link on what we done (method 1) https://www.vancouvericf.com/nudura/technicalDetailsFloors.php with fixing the timber and pouring the concrete.

@scottishjohn i fixed my timber on the ICF for first floor then poured concrete. Worked a treat for me.

I didnt know such material exsisted!

Best I found was £90 plus vat for 75mm with anti bacterial coating 50m roll.

@Russell griffiths Sorry to change subject but what's the xps500 coming in at m2 @ 100mm?