MikeSharp01

But only in freezing weather, so about 2 days a decade down here.

Which one did you eventually go for?

I think that means you have boards that are butted up against one another but have no support behind the joint, I guess those at 90deg to the joists. This means they are hanging in the air and so they will move relative to one another and there will be cracks eventually - taping should help but I was once, several times really and many years ago, told by a very old plasterer (Henry Cooper's brother actually) that all board edges must be supported so we put battens behind the cross joints as well to make him happy. They don't necessarily need to be anchored anywhere as they just ensure there is no chance of relative movement between the boards. There are no cracks in any of his plastering on our boards 20 years on.

My idea to make our seal is to use a bead of Orcon F or simlar to seal the airtight membrane to the floor nail a batten onto the soleplate about 10mm above the floor and put an Illbrook expanding seal along in the gap to force the membrane down onto the orcon F and close any gaps.

Yes tell the agent that for sure. Or something like "It seems to me that cut ridges are smaller than required from my understanding of the NHBC requirements".

Excellent to see the drawing with its annotation. You probably need to get a big washer (maybe 80-100mm dia) under the cap of the M16 resin anchor to avoid it just pulling through if it ever gets under load and if the timber has weakened as @TonyT points out it will very easily.

I think I get what you are trying to do can I ask a couple of questions. Do you have any housewrap type building paper on the outside of the timber cassette that can lap over the top of the red board to stop and water running behind the red board? (There will be a serious dew point issue behind the gladding anyway.) The red board will need to be impervious and very robust, so plastic come to mind and and joins will need careful attention. Have you considered wrapping the base, up both sides, of the cassette in some sort of membrane although this will be a moisture trap you might be able make it breath upwards?

Not sure I have not missed something but what stops you using your GSHP to circulate water through the GHT (http://www.ght.lv/home/) and not bother with the brine loop and presumably when needed in the summer you can cool the air that same way. You are payng some energy to run the brine loop after all. The 8KwH exchanger looks like a beast you could air condition a moderate place with that although perhaps not via MVHR. The sorts of flow rates the average MVHR can manage (Say 100m3Hr in a 3 bed Passive house) that unit would only deliver about 1kW of cooling but you might squeeze that to 2kW in boost mode. 2kW would be getting close to enough for many a passive house standard places around here but there are loads of other factors aren't there.

LINK!

Yes but you could compensate for that as well. We need to get to a circular economy if we can everywhere we can.

That could be achieved, somewhat, by @Delbot finding the equivalent weight of piles in scrap iron and recycle it to keep it circular?

+1 and also ensure all board joins are supported (IE Timber behind) and when you get it skimmed have all the joints tapped for additional board2board support although screws should be enough.

Helical piles and a frame built on them? Have look here: https://gbgs.co.uk/our-services/

You can find the JS Harris spreadsheet here:

Sealing it is no problem and where the pipe comes out of the walls it is (will be) insulated at both ends. Getting under the slab is a non starter at this stage, the original intention was to run the pipes down the outside, buried in pea shingle, and bring them in through the wall and this is still possible but I felt I could save a lot of cost (insulated pipe runs in 25mm dia are expensive) by using the in wall insulation and any heat lost will come into the house.

I have a plan to bring the ASHP-UFH 25mm (PEX-AL-PEX) flow and return pipes along inside the walls of our build. The Warmcell (other brands are available) insulation will be blown in around them to insulate them and they would be 150mm apart and 150mm from the inner surface of the insulation. The system will run in cooling mode and heating mode depending on season. Any thoughts on why I should not do this? My own thoughts are around the possibility of condensation forming on the pipe when in cooling mode and water and Cellulose fibre insulation are not good bedfellows!

Best thing is to start at the outside and work in with some questions: What appliances are we contemplating. Which way do you (or you for that matter) want to be looking when preparing food. Are we having an Island and if so what might you want on it. In the end you only need to chase out the above worktop sockets, from below the worktop, as everything else can be run in the service void behind the cabinets (not IKEA as they don't have much of one.) The real crunchers are getting the triangle right and the orientation.

Yes because you will only get (be able to afford) half a kitchen.

We discuss this here: AND HERE:

Thats a very good point - that is something the sun(amp) worshipers don't mention and I must look up how the Sunamp is handled for SAP calc.

Use whatever language you like and let the swear box gizzmo do the heavy lifting.

Welcome to THE forum for People like us.

Get some insulation on the outside of the beam, as PeterW says, even a thin layer of PU will break the cold bridge relatively effectively.

Welcome the THE forum for people like us!

Interesting, the whole choice of DHW has got no simpler since the advent of buildhub or its predecessor!