Mr Punter

It only seems to add water to bagged mix. If it could properly mix the dry ingredients (gravel, sand, cement, admix etc.) it would be worthwhile, so you could make concrete, screed, render, mortar etc.

True but the AC could be over 10x the MVHR

Go back to the supplier/installer and ask for this. It could be a tag or EN number.

Do the MVHR and just put AC in the rooms that need it. If you have lots of PV on the roof the AC will cost nothing to run during the day.

You could suggest that you will make an official complaint. Your LA should have a complaints procedure.

Who has done your inspections to date? If you have a name it would help. Give him a call. Bear in mind it is the end of Easter hols today, so next week should be better. Unless they are no longer doing Building Control (which they are legally bound to carry out) you should be able to get someone out fairly soon. Be nice and don't lose your rag.

There will be loads of solar install firms who work near you. Get 3 quotes and pick one. It may be that they will not fit used kit or have wiring by others but you can ask.

That will be quite a few holes in the web of the existing beam. Have you worked out how you are going to fix the decking?

I think similar or more expensive, depending on the range. Roseview are based on standard upvc profiles from Rehau and do lots of extra customisation and finishing. Their top range is almost indistinguishable from timber.

I have used the "Rose" range in a couple of properties. They are pretty good lookilikies for trad timber.

Hopefully Tim can recommend other trades. It often works like that.

Not sure what the blocks are, but it may be best to render over these. You may need to prep by cleaning off dust and giving a coat of rend aid.

Just fit a mushroom vent to the pipe.

If you are not in an exposed location you could have got away without these as the render would stop water getting through. You probably have weep vents every 450mm but some have been covered by render. You could have a dig about to find more or cover up any you don't like, but either way it is very difficult to make it match in with the render.

Nice job @DIYMichael. I really like the timber internal linings / reveals / cills for the door and windows.

No I didn't mention EWI. You need to fit counterbattens on top of the rafters and fix through the externally fitted insulation boards, hence long helical fixings needed. No need to fill between the rafters, although you could use a small amount subject to satisfactory condensation risk analysis.

If you have external insulation you will need to work out how to fix battens / counterbattens. You will need a lot of very long fixings. I think the helical type work well. Expect to spend about £7/m2 in fixings for counterbattens.

No, not viable. They are perforated clay and have poor insulation values. Warranty providers like a drained and vented cavity, so a single skin will not work. The blocks shatter if you drill them. You will struggle with plumbing and electrics. Airtightness is hard to achieve. More expensive than normal blocks. Just move on from these and save yourself a headache.

When the cavity is fairly wide the risk of voids is almost eliminated with blown eps beads. Probably the safest choice. Also if they miss, say an entire elevation it can be filled later.

Sometimes I have had the sockets on a flex under the units. Quite a few appliances have moulded plugs and it may be that any warranty can be voided if you cut them off. It is not simple to anticipate what is needed. I have had induction hobs needing hard wiring on a separate circuit where others are plug in 13A. I like under cupboard lights to be switched from an extra gang on the main light switch, which can also be a challenge.

Leica are a very good brand but IMO too expensive. The Chinese stuff is so cheap it is hard to say no.

You don't need to be qualified to build a house in the UK. ICF is fairly easy DIY. It would be more impressive if you built in brick and block. No requirement for Gas Safe if it is just for you but would be my preferred option.

The Dritherm 32 slabs are easy for the bricklayer to fit, easy for wall ties, decent u-value, don't make a mess if the wall gets drilled and easy to clean up mortar droppings. EPS beads are good too but you said you are not keen on them.

Proper rough job. It would still be rough without the rigid insulation, which elevates it to farcically bad.

Gas Safe plumber would be my answer.