Bingo! On an old HDD I found ancient (2013) WUFI case studies, as discussed here from my memory, most recently in
http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18146&page=1#Item_26 .

I also found the WUFI 5.1.exe, which loaded and opened, where previously it had been time-limited to 6wks following the WUFI course. So, back in business! tho am sure to pay to legit-upgrade to current WUFI 6, which I think has changed a lot.

In that thread, the construction discussed was:

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Rafters (or studwork), plasterboard, skim and vapour-breatheable paint internally, which can be punctured at will for electrics etc; 12 ply sheathing (or 11 OSB3) gapfilling (polyurethane) glued and screwed/nailed externally, as air barrier, blown full of Warmcel insulation.

EPS (or wood fibre) insulation; if 95 rafters then 150 EPS; if 145 rafters then 100 EPS, glued external to the sheathing EWI-style, with highly gappy glue application, to allow unimpeded water vapour passage. Board-edge joints filled with expanding foam, by long nozzle pushed in full depth, so filled full depth from inside outward. Bead-board EPS is by far least environmentally offensive, compared to any foam-board insulation such as PIR, and is sufficiently vapour-breatheable.

Breather underslating felt, downslope battens, crosswise tiling battens, tiling.

This design, fully breatheable without any vapour barrier (VCL), results from my one opportunity, years ago, to play with WUFI. I tried many use-cases, and for this type of construction, found it performed much better without any VCL. Note, there is a (vapour permeable) air barrier layer and a (vapour permeable) external wind barrier layer. I put this superior performance down to its maximisation of re-drying potential, unimpeded both outward and inward. With or without VCL, there is, at some times of the year, interstitial condensation in the outermost centimetre(s) of the EPS, but this is harmless as there's no embedded timber in that zone. Neither EPS or woodfibre mind such intermittent wetness, as long as fully re-dried soon enough, whether diunal (winter sunny day) or seasonal (after a long cold winter).

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I find the case studies neatly arranged and hopefully useable to convince Bldg Insps. We shall see. Screenshots attached:

WUFI 1 OSB shows the water content in the mid-sandwich OSB layer, with no VCL.
WUFI 1 EPS shows ditto in the outboard EPS layer;
WUFI 5 ditto ditto are with standard inboard VCL.
WUFI 6 ditto ditto are with Intello variable VCL.

Intello works better than standard VCL. But no VCL at all works much better than both!
What do we make of that?

Note that vertical scales differ, so need to look at the numbers, not just graph shape. Print em out - hard to compare otherwise.

More case studies for me to verify with my own eyes then!

jpegs - when composing your post, below it is Attachments>Browse - click that, then in Explorer, which opens up, navigate to the folder where the jpeg is filed on your computer, select the jpeg and click Open. It attaches.

I cannot see an attachments option. Where should I be looking?

P.S. what does the 'big input' button do?

See the picture below which is what I see. Do you not see this?

No, I just have an add comments button.

No format, Emoji, or attachments :-(

What device are you using? Using a browser on a regular computer, or even a tablet, should give you a sensible interface.

Just had a look using Edge (I don't normally use it on my laptop, usually Chrome) and can confirm that there are format options but no options for Emoji, or attachments.

How strange.

Various points in no particular order.

(1) Your first post in the thread isn't very clear, at least to me. It seems to be talking about roofs but the building inspector is talking about walls? Your post doesn't seem to mention what the outer part of the wall looks like. Is there cladding or render or what? Is there a drainage plane and vented cavity? Is the render breathable?

(2) the building inspector is clearly wrong quoting 5.17. It doesn't 'require' anything. It simply states one case where a construction is 'deemed to satisfy'. As you say. But what is 'EWI on masonry'? 5.17 clearly isn't and from what I can make out yours isn't either?

(3) C2 doesn't require an absence of condensation as the BI seems to claim but instead requires "The walls ... adequately protect ... from harmful effects caused by: ... (c) interstitial and surface condensation". So as you say, what is required is that any condensation that does form dries out before it does any damage.

(4) I don't think you're stuffed. You need to go back with a reasoned argument, or go to his boss (that's what I did with mine) or change your BI firm.

Norfolk has a number of PH BTW, so they're not all ignorant, inbred yokels. My building inspector was in Norfolk and our walls are (breathable) render directly on rottable organic material. I expect there's condensation in there quite often.