JohnMo

Horizontal cylinder?

No need to add a second outlet, if it's a pain - just do two ducts to a single outlet 2x90mm to 125mm plenum.

Looking again now it's simplified the pantry supply isn't really adding to anything. The plant room extract is drawing air through that room anyway. Having the supply causes a short cut from pantry to plant room. Do double 90mm duct to lounge, everything else should be fine in single 90mm ducts. If in loft you will need insulation on ducts. Or build a PIR tunnel for the ducts. Build the MVHR into an accessible insulated box to stop heat gain in summer and cold in winter. Loft hatch will really need to incorporate a ladder for access. Floor loft for access to allow filter and general maintenance to MVHR. MVHR will need a dry trap for condensation drainage. Since you have moved the MVHR is there any reason not to move back to where it was and take the inlet outlet out the other end of the building by diner. Then all the possible noise is well away from bedrooms. Observation pantry seems to take up a lot of space for effectively a corner cupboard and what is the appliance garage? I would look to simplify the pantry, appliance garage and coat store. You have 4 doors in that area which is very busy. Do you need a plant room? Cylinder is making space too much of premium, you have loads of dead space in the loft, your MVHR is there already. Assume you have a heat pump UFH manifold could go in the utility where the cylinder is shown. Then have a more usable utility.

Move kitchen extract further along the wall to the gap between kitchen units and the other unit in dining. You don't need the supply by the lounge door. Just supply more into the lounge, around 60m3/h, it will spill 45 into kitchen and balance will flow into utility sweep the whole kitchen diner. Air supplies to bed 2 and physio room will spill down corridor, under doors to bathroom and ensuite. The extract in the hall messes this flow8 path so is not needed. I would do a combi supply extract outside wall unit and the the ducts can run together from MVHR unit to external wall. I would follow passivhaus flow rates for bedrooms, maybe slightly higher for your physio room if in regular/daily use. I would also be tempted to change description to bedroom on your plan.

Think building has been there since the 70s, so for original structural engineer, not sure they would be liable, especially as they have added more buildings on top of the original. Looks like a bodge splice, then covered in fire proof paint to hide it.

Same stuff as in the photo by @Mulberry View. 5 years since I bought it.

Option 3 move doorway

16mm is supposed to have a min bend radius of 80mm. But getting that without kinks not easy. I would bank on 150mm being nearer min radius.

Inlet/outlet seem a long way from MVHR unit. You only really need 1 extract from kitchen. I would locate the extract between the island and the dining area towards the wall units and have no supply in there at all. Air will travel from lounge and sweep area any way. No need for supply or extract in cupboard areas. Pantry supply or extract? Look at airflow paths from a supply terminal and see the shortest travel path to an extract and make sure you sweep all floor areas that are normally used (not cupboard etc)

Mine came from here, good service https://enviroform-insulation.com/window-posts-and-lintels/

There must be different grades of it, as mine was well flexible, I actually stored it rolled up.

Or a more modest normal install. I have a 5 flow and returns on one unit and 2x on the other.

I made insulation corners a bit bigger than the tape lines to enable lots to wriggle room. Once screed had cured, broke out the insulation. Did what I needed when bathroom etc was being done, then back filled with cement mix.

National grid live feed in the battery app.

As long as the secondary RCBO can trip without the main RCBO also tripping, if it does trip then mains power the relay base power is also cuts out. So question - does the second RCBO actually serve any purpose. Wouldn't you just kill the house power in total if you have a fire not faff with this bit and not that bit. If it's electric related fire your main RCBO is going trip anyway pretty quickly. You may be overthinking making it to complex it as you say to others

Depends where you are our current mix from National Grid in NE Scotland is 80% wind and 20% solar at 2pm

Long lengths of solid metal duct around 125mm dia maybe some of it bigger. Noise attenuation between every room. Great if you don't want to hide it away such as an industrial look. Pretty pants otherwise without loads of pre-build planning to accommodate.

Good chance, you may need to put a slight angle to get water to drip where you want it too. A normal heat/cool one has a drip tray to manage this

You most likely start making water at the heat exchanger, so will need to add some form of drain.

I would consider it generally rubbish due to low flow rates for cooling. However you can look at a different way as a dehumidifier to the incoming air. This will actively reduce house humidity and allow more margin from dew point for UFH (cooling), so you can run it cooler with no dew point issues.

Mine came with double sided tape. Although I actually upgraded most of it 25mm PIR in the end

I bought mine from Outsourced Energy, not sure if they still sell them. Hep2O do them. Also a quick search https://www.google.com/search?q=valved+water+manifold&client=ms-android-oneplus-terr2-rso3&hs=auXV&sca_esv=3b84e253abc71a61&sxsrf=APpeQnuZRlilx-yilcXRHpmgyLjX5DCNig%3A1783403463600&ei=x5NMarudJImchbIPtaSIsAI&biw=360&bih=664&oq=valved+water+manifold&gs_lp=EhNtb2JpbGUtZ3dzLXdpei1zZXJwIhV2YWx2ZWQgd2F0ZXIgbWFuaWZvbGQyBxAjGLACGCcyCBAAGAUYDRgeMggQABgFGA0YHjIIEAAYBRgNGB4yCBAAGAUYDRgeMggQABgFGA0YHjIIEAAYBRgNGB4yCBAAGAUYDRgeSIkuUNAiWMokcAF4AZABAJgBgAKgAaIEqgEFMC4yLjG4AQPIAQD4AQGYAgOgAsQCwgIEEAAYR5gDAOIDBRIBMSBAiAYBkAYEkgcDMS4yoAeyEbIHAzAuMrgHuwLCBwUyLTEuMsgHHYAIAA&sclient=mobile-gws-wiz-serp

Very true. A 3x MPPT hybrid inverter may be a better solution. Assuming a DC battery. If AC coupled battery any 2x MPPT inverter in addition to the existing inverter would be fine. Just need to manage the export limit.

I was interested also, so I had an internet search. Compared to one of my units (Titon HRV), see images below. Heat exchanger size on the Rega is very small. Insulation between air streams almost none. Casing insulation almost none. Just about as basic as you can get - maybe and most likely poor performance as a result. Fan motors on Rega mounted in the steelwork, Titon mounted within the insulation, giving better noise attenuation and vibration dampening. Electronins away from where any water could collect etc etc Rega unit Titon HRV unit

Would suspect the product is the difficult basket from the reviewers perspective, i.e. no idea what they are looking at. Suspect a note stating the full structural engineering completed by Structural Engineer and reference his/her drawings. Plus send the instructions from ICF provider. I had to do with our building warrant.