Mr Punter

It looks very difficult to reconfigure. Round here they often add an extra floor, remove most internal wall etc when doing a bungalow. Have you looked around to see if there are other properties that would suit you?

The insurance rebuild costs are often higher than the actual build costs. It may take account of demolishing existing and maybe removing foundations and services before starting again, with a generous allowance for fees, prelims, contingency, overheads and profit.

This arrangement happens all the time in England. Conditional Contract or Option Agreement are the standard means. With a conditional contract, you exchange contracts at an agreed price subject to, in your case, obtaining planning consent for erection of a new dwelling etc. There will be other constraints to cover time allowed, appeals, fencing and boundaries, access, working times etc. Once the conditions have been met you are obliged to complete the purchase.

Unless you have someone in mind to take on the second plot, just offer for the one you like best. Major hassle and risk once you step outside the self builder role.

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.